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Rumors => EOS Bodies => Topic started by: shizam1 on April 02, 2012, 08:13:54 AM

Title: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 08:13:54 AM
My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body.  I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it.  For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4.  I lost many good shots because the 5DIII took 2-3 seconds to focus.  I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ).  For AF, I had "one shot" selected, and the center point with the 4 surrounding points.  I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some.  The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus.  The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60.  Oh, and I had a flash on, putting out that red focus assist as well during all this testing!  Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same.  I've also seen people post results of miraculous AF improvement with the 5DIII...
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bart van Dieken on April 02, 2012, 08:21:10 AM
One thing that might be the problem is that the focus assist beam is pointed at the center of the image and therefore only helps the center AF points...not the outer AF points.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: BillyBean on April 02, 2012, 08:28:22 AM
Well, my paranoia is starting to kick in now. I can get a 5D2 for £1500, get decent IQ and put up with rubbish AF, or I can get a 5D3 for £3000, get decent IQ and put up with rubbish AF.

Hmmm... tricky choice.

I wonder if improved firmware will make this easier?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 08:34:07 AM
One thing that might be the problem is that the focus assist beam is pointed at the center of the image and therefore only helps the center AF points...not the outer AF points.

Yeah, and if you re-read my post, I had center point selected, with the four surrounding points as well :)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bart van Dieken on April 02, 2012, 08:37:55 AM
Billybean i can relate to your difficult choice...

I'm going to buy a 5d MK2 second hand from someone for 1250 euros (with 1 year warranty left) + 16GB 400x CF and an extra battery...and a sunsniper strap.

To me it sounds like a pretty good deal to me plus I got 2250 euros to spare to buy 1 or 2 great lenses!!
I'm so glad that it's finally over for me...5d MK3 is a great cam for someone else who has got loads of money to spare. I actually want more money coming into, then going out of my bank account ;-) A 5D MK1 or MK2 wont be the difference between a normal income from photography or a big income.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 08:41:37 AM
Yeah, maybe the AF is much better for tracking moving objects, but it didn't seem to help me much in a normal dark wedding reception.  Now I probably won't upgrade my other body, and will get a new lens instead.  I wonder if the new 24-70 will focus faster than those primes in a dark situation?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: ippikiokami on April 02, 2012, 08:56:32 AM
Strange... I was shooting a concert where I had to use around 12800 - 25600 iso and had it straight on center point AF and it was focusing amazingly (in that kind of situation my 5d2 wouldn't even try). In what situations did you try the expanded? Not trying to doubt you but it does focus much differently than the 5d2 when you put it on the expanded mode and if you're not used to it then it might have caused you problems.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: tt on April 02, 2012, 08:56:40 AM
Does the focus assist work from the ex II 580 with the mark III?


Did you try central point only?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 09:04:16 AM
Strange... I was shooting a concert where I had to use around 12800 - 25600 iso and had it straight on center point AF and it was focusing amazingly (in that kind of situation my 5d2 wouldn't even try). In what situations did you try the expanded? Not trying to doubt you but it does focus much differently than the 5d2 when you put it on the expanded mode and if you're not used to it then it might have caused you problems.

Well, like I said, I had it set to center point, with the af point expansion on.  My understanding is it would try to use the center point, but would also use the 4 surrounding points as well if it was having problem with the center point.

But like I said, I also was comparing with the 5DII on center point only, and both were acting pretty similarly.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Alker on April 02, 2012, 09:06:57 AM
Every new camera seems to have AF problems.
Mine 5D mark iii is superb with his AF
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: logaandm on April 02, 2012, 09:12:12 AM
I also find it pretty strange. I just tried my Mark III and it focuses really well in low light unless I am trying to focus on something with low contrast, like black on black. Mind you, I am not using any focus assit beam or a flash. Maybe a flash alters the focus logic.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 09:17:35 AM
I also find it pretty strange. I just tried my Mark III and it focuses really well in low light unless I am trying to focus on something with low contrast, like black on black. Mind you, I am not using any focus assit beam or a flash. Maybe a flash alters the focus logic.

Well, I was surprised as well.  I was expecting better AF performance in low light than my 5DII, but was getting the same result. It was pretty dark though, I was just expecting better.  Even focusing on a red fire alarm panel on a white wall in the venue was taking 1-2 seconds.  I'll play around some tonight and see if I get anything different.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: agierke on April 02, 2012, 09:31:03 AM
i have been under the impression that the primes are not fast auto focusing lenses. i dont have any yet but i have worked with plenty of people who have. i have especially heard the 85mm L is a bit of a dog with AF. i'm on the fence right now about incorporating them into my work but even if i do i cant see myself not continuing to rely on the 24-70 and the 70-200.

i wonder if a more accurate test of the new AF system might be performed using the 70-200mm F2.8L? anyone have more experience that could enlighten us on this matter?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 09:35:16 AM
i have been under the impression that the primes are not fast auto focusing lenses. i dont have any yet but i have worked with plenty of people who have. i have especially heard the 85mm L is a bit of a dog with AF. i'm on the fence right now about incorporating them into my work but even if i do i cant see myself not continuing to rely on the 24-70 and the 70-200.

i wonder if a more accurate test of the new AF system might be performed using the 70-200mm F2.8L? anyone have more experience that could enlighten us on this matter?

Yeah, I have the 70-200 f/2.8L II, but no way I'm using that in a small,crowded reception area!

Wedding photographers like to use fast primes in dark areas, for more natural looking photos with minimal flash.  I will usually shoot those primes anywhere from f/1.2 to f/2.0 so that's a 1-2 stop improvement ( 2 to 4 times as much light ).
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: JR on April 02, 2012, 09:37:58 AM
Strange... I was shooting a concert where I had to use around 12800 - 25600 iso and had it straight on center point AF and it was focusing amazingly (in that kind of situation my 5d2 wouldn't even try). In what situations did you try the expanded? Not trying to doubt you but it does focus much differently than the 5d2 when you put it on the expanded mode and if you're not used to it then it might have caused you problems.

Well, like I said, I had it set to center point, with the af point expansion on.  My understanding is it would try to use the center point, but would also use the 4 surrounding points as well if it was having problem with the center point.

But like I said, I also was comparing with the 5DII on center point only, and both were acting pretty similarly.

Was your 5d mkii also using point expansion?  I know when i tried the mkiii i did not get good result with point expansion.  I preferred using single center point with no expansion.  Did you tried that? 

For the shots you did have good focus, were you happy with image quality?

Jacques
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 09:38:19 AM
You have some very fast lenses, I have the 85L1.2ii as well, I'm  surprised you didn't opt to use single spot/point AF ??? Were you using the widest aperture?

I was normally shooting between wide open and f/2.

Well, I was using the center AF point, but with expansion, so that is supposed to mean it will use the 4 surrounding points if it can't lock AF with the center.  So that SHOULD be similar performance to using just the center point, but with the added benefit of if it can't lock on, it will try with the other points.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 09:41:02 AM

Was your 5d mkii also using point expansion?  I know when i tried the mkiii i did not get good result with point expansion.  I preferred using single center point with no expansion.  Did you tried that? 

For the shots you did have good focus, were you happy with image quality?

Jacques

I use center point for 5DII, I don't think there's any sort of expanion with that camera.  It's either pick a point, or pick all.  I didn't try just center... if that does better I will be surprised and dissapointed, because it goes against what the literature says.

The AF seems to be very accurate once it does lock on.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Sallivres on April 02, 2012, 10:04:49 AM
Oh, and I had a flash on, putting out that red focus assist as well during all this testing!

According to the manual page 77:

"With single-point Spot AF,  focusing with the Speedlight's AF assist beam may be difficult."
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: msdarkroom on April 02, 2012, 10:08:30 AM
Oh, and I had a flash on, putting out that red focus assist as well during all this testing!

According to the manual page 77:

"With single-point Spot AF,  focusing with the Speedlight's AF assist beam may be difficult."

He wasn't using single point spot AF.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 10:13:45 AM
Correct me if I'm wrong (I don't have my 5Diii yet) you can select a single focus point (non-central) as well? Bacause I know from experience that centre-spot focus-recompose can be pretty dodgy with the 85L 1.2ii.
at least, definitely at f1.2, f1.4.

Yep, you can select any point.  And then, you can select a "mode" to go along with it.  By mode, I mean you can tell the camera to take that point you selected, and use JUST THAT POINT, or use 4 points around it ( making a + ), or 8 points around it ( making a square ), or use a zone and not a point at all, or use ALL points.

Focus and recompose can cause difficulty with really shallow DOF, you are correct.  But I'm talking about the time to achieve AF, not whether by using focus and recompose you get a bad part of the photo in focus.
Title: Enough on this topic for me
Post by: shizam1 on April 02, 2012, 10:16:29 AM
I was just giving people a heads up with my experience.  The AF might perform better in other lighting situations, but for me, trying to use it last night at a dark wedding reception, it did no better than the 5DII, and potentially took even longer to achieve focus.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 10:23:05 AM
I had a similar experience that in low-light using the point expansion made the AF sluggish.

I turned off the point expansion and the AF was stellar in low light.  I found that with point expansion turned off, the outer cross-type sensors on the Mark III were just as fast and accurate as the center point on my Mark II.  This is with an 85 1.8 and 35 1.4. 

The light level was about 1/120, f2.0, iso 6400.

I'm finding that changing the setting of AF on the Mark III can drastically change the performance in different situations. 

My AF settings now are limiting the selectable points to 15 point, direct multi control selection method, single point. These settings give me tremendous results in most situations.  WAY better than the Mark II.

My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder and the "M" button to change the AF from single point to fine point when I'm making portraits at a slower pace.


Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 10:26:04 AM
I had a similar experience that in low-light using the point expansion made the AF sluggish.

I turned off the point expansion and the AF was stellar in low light.  I found that with point expansion turned off, the outer cross-type sensors on the Mark III were just as fast and accurate as the center point on my Mark II.  This is with an 85 1.8 and 35 1.4. 

The light level was about 1/120, f2.0, iso 6400.

I'm finding that changing the setting of AF on the Mark III can drastically change the performance in different situations. 

My AF settings now are limiting the selectable points to 15 point, direct multi control selection method, single point. These settings give me tremendous results in most situations.  WAY better than the Mark II.

My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder and the "M" button to change the AF from single point to fine point when I'm making portraits at a slower pace.

Thanks for the helpful info, I appreciate it!  I'm dissapointed in Canon and the literature then...  I will be trying this out tonight in my house when it gets dark
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Axilrod on April 02, 2012, 10:52:04 AM
Man if those are the results you got you really need to play with the settings.  I shot all weekend and was blown away by how many shots were in focus, it was like I couldn't miss.  And this was shooting fast moving subjects on AI Servo.  I just use Spot AF, all the expansion and auto selection is unchecked.  But seriously, I don't think I'll ever be able to use my Mark II again it sucks so bad compared to the III, so it must be your settings.  I use the same lenses as you do for the most part. 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: JR on April 02, 2012, 11:07:05 AM
I vaguely recall reading somewhere that the 5Diii has focusing issues when used with the older speedlites 580exii and older, and only functioned correctly with new 600ex-rt :(, anyone else recall reading this and where? Hope it's not true.

I was thinking that too since i had mixed result with the 580ii and my mkiii, however i was told the only issue was that the older flash do not see all 61 points (only 45 like in the previous 1 series).  So using only the center point should not impact the flash performance - in theory!!!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: rlarsen on April 02, 2012, 11:12:23 AM
Both of my cameras are impressive, and work very well. I've decided to spent more time with them and learn a lot about the feature options before using them for work. I'm using other cameras for the time being for assignments.
When the 1-DMKlV came out, a lot of people had issues until they learned more about the complex AF.

A friend of mine, an experienced AP photo bureau photo chief in a big city, had issues with his Mark lV until he learned the optimal setup for AF. His results then became consistently excellent.

Rudy Winston, a good guy and tech expert from Canon, has an online series describing the new 5D /  1DX AF system.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Daniel Flather on April 02, 2012, 11:20:15 AM
With my 580's light my 5D3 can focus in total darkness, but I only ever use spot AF.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: PhilDrinkwater on April 02, 2012, 11:20:33 AM
I'm honestly surprised to hear this.  I even find my 5d2 doesn't struggle like you're suggesting and I shoot some very low light venues (ISO3200, 160th, f1.6).

What I may find is that the 5d2 doesn't achieve CRITICAL focus, but it's only a tiny bit out and it hardly ever hunts and is pretty quick.

Hope you get it sorted.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 11:24:22 AM
Rudy Winston, a good guy and tech expert from Canon, has an online series describing the new 5D /  1DX AF system.

It is a good article.  But nowhere does it say to stick to "single point AF" if you want fast AF.  So unfortunately it's one of those things people need to learn and then share that knowledge.  I wish it had been documented, because I would have used it last night and would have gotten more keepers from the reception.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: mrmarks on April 02, 2012, 11:26:14 AM

Rudy Winston, a good guy and tech expert from Canon, has an online series describing the new 5D /  1DX AF system.

The links to Rudy's articles can be found here http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article (http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Daniel Flather on April 02, 2012, 11:30:14 AM

My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder...


What?  I can't seem to achieve this, explain.  Are you truing the quick control dial, or the main dial?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 11:44:34 AM
I'm honestly surprised to hear this.  I even find my 5d2 doesn't struggle like you're suggesting and I shoot some very low light venues (ISO3200, 160th, f1.6).

What I may find is that the 5d2 doesn't achieve CRITICAL focus, but it's only a tiny bit out and it hardly ever hunts and is pretty quick.

Hope you get it sorted.

Yeah, I've shot lot's of low light stuff before, and maybe this was more challenging/darker than I recollect...  Hopefully I can squeeze better AF performance out of the 5DIII by going back to single spot AF like I used to do with the 5DII
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: rlarsen on April 02, 2012, 11:45:30 AM
Single point without expansion will be fine as long as that point is directed at something with a little texture.
I'm curious to learn, how with the NEW system, expansion choices etc. effect AF speed.

I recall having trouble with my older cameras shooting night football. If the sensor was on a jersery between the number and the waist band, the solid color was a bitch to track. Often I would sacrifice composition to place the sensor on texture and contrast. The new 1-DX will also track color and faces.......for an extra $3500

Good idea to learn the stick-shift before leaving the driveway :-)  ( for me anyway )
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: april on April 02, 2012, 11:46:26 AM
Rudy Winston, a good guy and tech expert from Canon, has an online series describing the new 5D /  1DX AF system.

It is a good article.  But nowhere does it say to stick to "single point AF" if you want fast AF.  So unfortunately it's one of those things people need to learn and then share that knowledge.  I wish it had been documented, because I would have used it last night and would have gotten more keepers from the reception.

if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting  61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: rlarsen on April 02, 2012, 11:50:14 AM
This was helpful to me, and I will use some of the suggestions.
http://www.atrero.com/articles/canon-eos-5d-mark-iii-af-settings/ (http://www.atrero.com/articles/canon-eos-5d-mark-iii-af-settings/)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: pdirestajr on April 02, 2012, 11:57:09 AM
The original poster mentioned the focus was on "one shot" doesn't that mean if the subject moved at all (or the photographer), the focus point would be off- since it doesn't sound like it was in servo? Especially at wide open apertures where DOF is super shallow.

I only have a 7D, but I find I nail focus on 90% of my shots when I have it in servo as opposed to one shot. Unless it is a still photo obviously.

And also 1/60 shutter speed is a little on the slower side for moving people no? Seems like natural motion could create blur here.

I've never shot a wedding or used a 5D, so this is just me guessing based on my experience with AF and what the OP initially said.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: PhilDrinkwater on April 02, 2012, 12:05:43 PM
The original poster mentioned the focus was on "one shot" doesn't that mean if the subject moved at all (or the photographer), the focus point would be off- since it doesn't sound like it was in servo? Especially at wide open apertures where DOF is super shallow.

I only have a 7D, but I find I nail focus on 90% of my shots when I have it in servo as opposed to one shot. Unless it is a still photo obviously.

And also 1/60 shutter speed is a little on the slower side for moving people no? Seems like natural motion could create blur here.

I've never shot a wedding or used a 5D, so this is just me guessing based on my experience with AF and what the OP initially said.

You shouldn't be shooting in servo unless the subject is moving - it won't actually LOCK focus at any point.

I certainly would never do this and speaking to Canon they also don't recommend it.

The ideal situation would be to place an AF point over the persons eye and use one shot... :)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 12:11:58 PM
if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting  61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?

Well, more points could help you to avoid "focus and recompose".  The problem with the 5DII focus points, is there weren't many and they were all clustered around the center of the VF.  And more focus points could help with bright situations when using AI Servo with moving targets.  It just depends on what you are shooting, and what AF mode you need to be in.  For weddings, I normally use "one shot" drive mode, and might only switch to "AI-Servo" when bride is walking down aisle and that sort of thing.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 12:12:04 PM
One thing i'd like to know is this, in dark situations is having outter points on hindering the speed. Although i havent shot a reception as of yet and havent tested this out i prob wouldn't use the focus assist points in low light. From my testing my 5dm3 is a monster in dark lit areas and locks on focus pretty nicely. I can only expect it would be the same in any situation. What F stop were you using it lloks like all your lenses are low light monsters. You may need to look into calibrating it to your body. My 50 F1.2 focussed pretty dang well outta the box but i spent a lot of time and got my testing device out and decided to go with +5 for it. At f1.2 its pretty difficult to calibrate since the 85 1.2 and the 50 1.2 are difficult beasts to work with but when you get the shot forget about any other lens.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 12:21:51 PM
Man if those are the results you got you really need to play with the settings.  I shot all weekend and was blown away by how many shots were in focus, it was like I couldn't miss.  And this was shooting fast moving subjects on AI Servo.  I just use Spot AF, all the expansion and auto selection is unchecked.  But seriously, I don't think I'll ever be able to use my Mark II again it sucks so bad compared to the III, so it must be your settings.  I use the same lenses as you do for the most part.
Spot af in servo, i am surprised that wasn't a problem. Im pretty sure i read in the manual that moving subjects are best to not be using spot af point on because it is such a refined focus. Its def cool if it still worked but maybe they mean more like runners or sports its not a good setting and maybe with weddings people aren't moving too fast so its not a problem then...Cool to know though.
KEY INFO BELOW:
Also as a side note I can say without any doubt in my mind this is absolutely true in using fast primes, shooting in servo is a bad bad idea no matter what camera. I have tested it out on both my 1dm3, my 5d and now my 5dm3 and talk about a lens hunting, it was constantly moving in and out. Flip it to single shot and BAM it locks on focus. Literally if people knew this fact alone while working with fast primes, their keeper rate would be transformed!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 12:57:24 PM

My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder...


What?  I can't seem to achieve this, explain.  Are you truing the quick control dial, or the main dial?

Go to Custom Functions (the Camera with vertical lines underneath), go down to "Custom Control" and go to the "Set" button and change it to "ISO".

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 12:59:22 PM
Another setting that I use is the AF is only tied to the "AF-ON" button and not the shutter button.  This too is under the Custom Function settings.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: LetTheRightLensIn on April 02, 2012, 01:07:51 PM
if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting  61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?

Well, more points could help you to avoid "focus and recompose".  The problem with the 5DII focus points, is there weren't many and they were all clustered around the center of the VF.  And more focus points could help with bright situations when using AI Servo with moving targets.  It just depends on what you are shooting, and what AF mode you need to be in.  For weddings, I normally use "one shot" drive mode, and might only switch to "AI-Servo" when bride is walking down aisle and that sort of thing.

How does using assists help you not to do focus and recompose? It's actually FORCING that to happen at times.
If you are shooting fast lenses, wide open, close in, I'd think it might make more trouble, since it has a larger area over which to decided to toss the focus on and it might say make the eyes end up OOF I'd think.
It seems like a weird choice to use expansion points for the type of shooting you were doing, although I could be wrong no having been there.

That said, it sounds pretty worrisome, since that is what you would do for shooting sports at night and 2-3 seconds would make it ridiculously bad for shooting sports under poor lighting. I hope that is not the case.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tracy Pinto on April 02, 2012, 01:10:40 PM
I have found the AF on this camera to be a pleasure. It is fast and accurate.

 I would not recommend practicing on paying customers.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 01:16:19 PM
if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting  61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?

Well, more points could help you to avoid "focus and recompose".  The problem with the 5DII focus points, is there weren't many and they were all clustered around the center of the VF.  And more focus points could help with bright situations when using AI Servo with moving targets.  It just depends on what you are shooting, and what AF mode you need to be in.  For weddings, I normally use "one shot" drive mode, and might only switch to "AI-Servo" when bride is walking down aisle and that sort of thing.

How does using assists help you not to do focus and recompose? It's actually FORCING that to happen at times.
If you are shooting fast lenses, wide open, close in, I'd think it might make more trouble, since it has a larger area over which to decided to toss the focus on and it might say make the eyes end up OOF I'd think.
It seems like a weird choice to use expansion points for the type of shooting you were doing, although I could be wrong no having been there.

That said, it sounds pretty worrisome, since that is what you would do for shooting sports at night and 2-3 seconds would make it ridiculously bad for shooting sports under poor lighting. I hope that is not the case.
What you need to realize about this is the lenses used. We are talking about lenses people love and hate due to its refined focus in the barrel of the lens and the glass it needs to move, the 85 1.2 (I used to have), and the 50 1.2, (I now have) are tricky to work with and move slower than normal glass and the dof is rediculous, but the rewards are excellent. I dont think the 70-200 will be an issue in fact in my testing it is fast and dead on. All that said i havent used assist points yet im sure it will be excellent coming from a 1dx system. I will use assist when i shoot a race coming up and see how it fairs with the 70-200 II. I have always preferred single point however. I will never use spot af for sports, it won't be good! I will use spot Af for static subjects.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 01:17:17 PM
I would not recommend practicing on paying customers.

Me either, that's why I had two 5DII bodies with me in addition, and was going between them.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: unfocused on April 02, 2012, 01:36:35 PM
I'm a little amused at all the people on this thread trying to convince the original poster that it's all his fault and he just doesn't know what he is doing.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 01:42:50 PM
I'm a little amused at all the people on this thread trying to convince the original poster that it's all his fault and he just doesn't know what he is doing.

I agree... but I am glad there are a couple of people, who actually own the camera and have shot in similar situations,  that provided useful information to try and get better results out of the AF.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 01:45:00 PM
I'm a little amused at all the people on this thread trying to convince the original poster that it's all his fault and he just doesn't know what he is doing.
Hey anything is possible man. The most specific problem a person runs into with big glass is focus and i continue preaching to never use servo mode with big glass. People who have it should test out what i am saying and they will see just how much impact that can have. I'd say its more like we want to help and figure out where we may need to adjust how we shoot. At least that is what is true for me.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: dericcainphoto on April 02, 2012, 02:07:06 PM
My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder ...
This is one of the coolest time-saving features! I have limited my AF to cross type only. In your opinion, do you think just using the 15 points is better than using cross type only? Thanks for the input!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: briansquibb on April 02, 2012, 02:16:32 PM
The best way is to practice with a new camera in all the situations so if there is a problem then it can be sorted before you get to a critical shoot
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 02:23:25 PM
My other favorite features are pushing the "SET" button and the finger dial to adjust ISO directly in the viewfinder ...
This is one of the coolest time-saving features! I have limited my AF to cross type only. In your opinion, do you think just using the 15 points is better than using cross type only? Thanks for the input!

I limit the selectable to the 15 so I can move across the viewfinder quickly.  I also have the selection loop around the screen instead of stopping at the edges.

All 15 are cross type.  When I'm tracking in a lot of light I'll switch to the point surrounded by all of the points around it.

I do this because a lot of what I shoot on a wedding day is photojournalism so I need to be able to get across the screen with AF points very quickly.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: SandyP on April 02, 2012, 02:26:38 PM
Well, I mean, if other people suggest whatever, but if people out there are having great success with it as a wedding camera in all sorts of dark situations, then obviously the user/OP is doing something "wrong", or there is something wrong with his specific camera, and not the camera in general.

Ryan Brenziner and Jonas Peterson have been raving about how much of a game changer this is for Canon, especially for weddings (they're two huge names in the business), and hey, Ryan is basically a Nikon shooter saying that. They've been pumping out some great opinions on it lately.

So that isn't saying the OP is stupid, of course not, but obviously something is going on...
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: publiux on April 02, 2012, 02:29:26 PM
I had newborn shoot on Sunday. Focusing was spot on and fast. I did to a the AF microadjustments last week (+7 steps).
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mr Simpleton on April 02, 2012, 02:34:19 PM
So I had to try for my self... using Mk2 with center focus point, and the Mk3 tested with either spot or just center point, and/or expanded. Used same 70-200/2,8Mk2 lens swapped between the two cameras.

While the Mk2 gave focus confirmation almost instant, the Mk3 took it's time each and every time. I am sure the new Mk3 do have more precision, but still we are talking seconds here!

Even tried to alter from focus to shutter priority but of course had no impact on time till confirmation.
And yes this was in marginal light...
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 02:38:03 PM
Well, I mean, if other people suggest whatever, but if people out there are having great success with it as a wedding camera in all sorts of dark situations, then obviously the user/OP is doing something "wrong", or there is something wrong with his specific camera, and not the camera in general.

Ryan Brenziner and Jonas Peterson have been raving about how much of a game changer this is for Canon, especially for weddings (they're two huge names in the business), and hey, Ryan is basically a Nikon shooter saying that. They've been pumping out some great opinions on it lately.

So that isn't saying the OP is stupid, of course not, but obviously something is going on...

Thanks for saying I might not be stupid :)

I THINK the problem is I was using expanded area on the point I selected.  Some other replys said they had the same problem as me, and changed to single point instead and that made the AF much faster.  This is for "single shot" drive btw.

You would think something like that would be mentioned in all those reviews, or in the documentation, but I haven't seen anything like that.

Anyway... I'll be testing tonight and seeing if I can reproduce the slower AF that I was experiencing, and see if changing the mode makes the speed increase I'm hoping for and was expecting!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 02:40:14 PM
So I had to try for my self... using Mk2 with center focus point, and the Mk3 tested with either spot or just center point, and/or expanded. Used same 70-200/2,8Mk2 lens swapped between the two cameras.

While the Mk2 gave focus confirmation almost instant, the Mk3 took it's time each and every time. I am sure the new Mk3 do have more precision, but still we are talking seconds here!

Even tried to alter from focus to shutter priority but of course had no impact on time till confirmation.
And yes this was in marginal light...

So turning off the expanded didn't increase the speed for you in the 5DIII?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tracy Pinto on April 02, 2012, 02:43:36 PM
shizam1 you are not alone...Simpleton is right in there with you.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mr Simpleton on April 02, 2012, 02:48:14 PM
So turning off the expanded didn't increase the speed for you in the 5DIII?

Sorry to say, I could not see any major difference :( Seems that the accuracy has its price.
Still I new to this Mk3 and hopefully I just having my settings all wrong. But not many settings to alter in single shot though.

Looking forward to heard about your findings.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: LetTheRightLensIn on April 02, 2012, 02:52:29 PM
So I had to try for my self... using Mk2 with center focus point, and the Mk3 tested with either spot or just center point, and/or expanded. Used same 70-200/2,8Mk2 lens swapped between the two cameras.

While the Mk2 gave focus confirmation almost instant, the Mk3 took it's time each and every time. I am sure the new Mk3 do have more precision, but still we are talking seconds here!

Even tried to alter from focus to shutter priority but of course had no impact on time till confirmation.
And yes this was in marginal light...

Interesting. it would be interesting to try to see how the results from the Mk3 compared when forced to fire after the same time as the 5D2 had. One would hope it would do at least as well in terms of hit rate.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mr Simpleton on April 02, 2012, 02:59:48 PM
Interesting. it would be interesting to try to see how the results from the Mk3 compared when forced to fire after the same time as the 5D2 had. One would hope it would do at least as well in terms of hit rate.
Agree it seems like fun test, but that means controlled lighning and such... right now not feasable here. I'm sure some with the two cams can do this.

Still the "wait for confirmation" is buried deep into my spine... never ever mash the shutter. Time to re-learn?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Z on April 02, 2012, 03:11:24 PM
First up - I'm not a 5D3 or 5D2 shooter - I use a 7D so take my opinions with a grain of salt. However, a lot of the autofocus features that are 'new' to 5D3 users (AF point expansion, zone AF etc.) who have upgraded from the 5D2 are features that 7D users have been playing with for years.  Personally, the only time I use single AF point expansion, as OP did, is for AI Servo tracking of [fast] moving subjects.  In this scenario it reduces the odds of the subject moving outside the main AF point and causing the focus to hunt. For this purpose I find it particularly effective. If I were using One Shot (as OP was), a single autofocus point always suffices for me and I would never turn on point expansion for fear of overcomplicating things. As others have stated, I would first try turning off the expansion in that scenario.

The 7D manual at least agrees with me, describing AF point expansion thus:

Quote
The manually-selected AF point <S> and adjacent AF points <w> are used to focus. Effective when it is difficult to track a moving subject with just one AF point.

The manual describes how AF point expansion works in One Shot mode, but doesn't state why it would be useful. I don't mean to add to the tirade of hysterical "5D3 is awesome, you must be doing it wrong!!1" (after all it wouldn't be the first time Canon has screwed up an autofocus system) or to tell you your business, but it is a new piece of kit and teething problems are to be expected.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Kernuak on April 02, 2012, 03:31:46 PM

You would think something like that would be mentioned in all those reviews, or in the documentation, but I haven't seen anything like that.

The problem is, most of the reviews spend all their time shooting still life setups in their studio, instead of using the camera in real life situations. They simply don't spend the time getting to grips with things like the AF system, so can't really give a good indication of what it is like, let alone getting the best out of it in various situations.
I'll try to find the CPS article on the MkIII AF to see if it sheds any light.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: ew20 on April 02, 2012, 03:41:49 PM
I shot some surfing this weekend, just trying to get the hang of the 5D3.  Servo mode is amazing with the expanded points.   Because the motion is so erratic, I usually get about 40-50% in very good focus.  With the 5D3, that jumped to 90%.  It was hard to find shots that weren't in focus.

Right after, I swapped to one-shot to take a picture of the wife, and like some others here the focus confirmation seemed slow.  There was plenty of light, it just took an extra second for the confirmation to flash.  I was expecting pretty much immediate focus so I accidentally took a shot before confirmation, then took another right after to make sure I had a good image.  What was interesting is the focus on the two images was practically identical, I couldn't tell them apart.

I did have point expansion on and used the points on the left hand side of the frame for both images.  I'm wondering if maybe the shot does focus quickly, but the confirmation is lagging behind.  Or perhaps the central point you choose focuses quickly, but the AF system takes a little time to check the surrounding points to make sure everything is fine and dandy before giving confirmation.  I'll try with expansion off later and see if anything comes of it.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 03:45:33 PM
I just retested this 5dII vs 5dIII w/ the 70-200 f2.8 II (the 35 and 85 are at the studio and I'm at home).  The 5dII and 5dIII were extremely in focus speed at ISO1600, 1/6, 2.8.

This is interesting to me, so I'd like to hear more experiences.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Kernuak on April 02, 2012, 03:47:46 PM
The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: epsiloneri on April 02, 2012, 03:51:30 PM
The 5dII and 5dIII were extremely in focus speed at ISO1600, 1/6, 2.8.
Hm, a critical word is missing. Is it "similar"?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 03:55:37 PM
The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.

I think I read that as well, but my take was that the extra points wouldn't hurt, and would indeed help in case you landed on a low contrast area with the center, and then it would look with the extra points around the point you chose.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 03:55:42 PM
I shot some surfing this weekend, just trying to get the hang of the 5D3.  Servo mode is amazing with the expanded points.   Because the motion is so erratic, I usually get about 40-50% in very good focus.  With the 5D3, that jumped to 90%.  It was hard to find shots that weren't in focus.

Right after, I swapped to one-shot to take a picture of the wife, and like some others here the focus confirmation seemed slow.  There was plenty of light, it just took an extra second for the confirmation to flash.  I was expecting pretty much immediate focus so I accidentally took a shot before confirmation, then took another right after to make sure I had a good image.  What was interesting is the focus on the two images was practically identical, I couldn't tell them apart.

I did have point expansion on and used the points on the left hand side of the frame for both images.  I'm wondering if maybe the shot does focus quickly, but the confirmation is lagging behind.  Or perhaps the central point you choose focuses quickly, but the AF system takes a little time to check the surrounding points to make sure everything is fine and dandy before giving confirmation.  I'll try with expansion off later and see if anything comes of it.
I think that is something to look at, the lag thing notifying of in focus is sometimes not on when it shoots and i have it set to not take it til focus lock is achieved. this may be a bug in fact, since i have noticed that as well but didn't find anything out of focus so i didn't worry about it. If the camera takes the shot before notifying me and its in focus i guess if you are going to have problems then this isn't a bad one.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 03:58:20 PM
The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.

I think I read that as well, but my take was that the extra points wouldn't hurt, and would indeed help in case you landed on a low contrast area with the center, and then it would look with the extra points around the point you chose.
Which by all means shouldn't be as fast as one point doing the measurements i would think. Chuck Westfall says the 5dm3 won't focus as fast as the 1d because the voltage power of the battery system is no where near what a 1d battery is.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: eeek on April 02, 2012, 04:27:56 PM
Is this the one you are talking about:

http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml (http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml)

edit: this is for the 1DX, but it is helpful as well:

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12 (http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12)

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 04:30:22 PM
The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.
That is helpful information. If you find the link back that would be sweet.
This link has good info at the Canon learning center.
http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article (http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Tim Larsen on April 02, 2012, 04:41:16 PM
The 5dII and 5dIII were extremely in focus speed at ISO1600, 1/6, 2.8.
Hm, a critical word is missing. Is it "similar"?

yes, similar!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: neuroanatomist on April 02, 2012, 04:53:59 PM
edit: this is for the 1DX, but it is helpful as well:

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12 (http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12)

Thanks - that's a very helpful document!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: SeanNY on April 02, 2012, 05:03:40 PM
Strange... I was shooting a concert where I had to use around 12800 - 25600 iso and had it straight on center point AF and it was focusing amazingly (in that kind of situation my 5d2 wouldn't even try). In what situations did you try the expanded? Not trying to doubt you but it does focus much differently than the 5d2 when you put it on the expanded mode and if you're not used to it then it might have caused you problems.

If you hadn't already written that, I would have written the exact same thing ... except that I didn't even set center point AF yet. 

I shot a concert on Friday night with my just-out-of-the-box Mark III with my favorite 85mm F1.2L lens.  I have done the exact same thing many times before with my Mark II and I can say for certain the focusing was much quicker.  I would go so far as to describe it as snappy.

I was mostly shooting at 1/160th - 1/400th of a second, aperature 2.8 - 3.4 and ISO up to 12,800.

In the interest of full disclosure:  The only setting I changed on the camera before the concert was that I selected only cross type AF points because I thought that would mean only cross type AF points would be automatically used (I thought this might make focusing faster).  But reading the manual later, I think that just means only cross type AF points will be manually selectable.  Since I didn't do any manual selection, therefore, I think this setting was irrelevant for me.

Here is a typical shot from that concert (at 12,800 ISO!!):

http://www.flickr.com/photos/edwinland/6886762262/#in/photostream (http://www.flickr.com/photos/edwinland/6886762262/#in/photostream)

It may look like the subject was posing for me but he was actually moving forward from the back of the stage while playing his guitar, and I managed to catch him the one half second he glanced directly at my camera.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 05:08:53 PM
I just did some shots in my basement, lighting was dark, ISO 1600 f/2.8 and 3 second shutter speed.

It would take 2-3 seconds to acquire focus, and changing between expansion mode and not didn't do anything.

So at least for my camera, in really dark scenes, changing that setting won't give better AF performance.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 05:14:02 PM
I just did some shots in my basement, lighting was dark, ISO 1600 f/2.8 and 3 second shutter speed.

It would take 2-3 seconds to acquire focus, and changing between expansion mode and not didn't do anything.

So at least for my camera, in really dark scenes, changing that setting won't give better AF performance.
now try it with a 70-200 instead of an 85mm F1.2 or whatever you used.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 05:15:55 PM
I just did some shots in my basement, lighting was dark, ISO 1600 f/2.8 and 3 second shutter speed.

It would take 2-3 seconds to acquire focus, and changing between expansion mode and not didn't do anything.

So at least for my camera, in really dark scenes, changing that setting won't give better AF performance.
now try it with a 70-200 instead of an 85mm F1.2 or whatever you used.

I actually used my 70-200 f/2.8L II
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 05:20:52 PM
I just did some shots in my basement, lighting was dark, ISO 1600 f/2.8 and 3 second shutter speed.

It would take 2-3 seconds to acquire focus, and changing between expansion mode and not didn't do anything.

So at least for my camera, in really dark scenes, changing that setting won't give better AF performance.
now try it with a 70-200 instead of an 85mm F1.2 or whatever you used.

I actually used my 70-200 f/2.8L II
DOH! That sucks man, what are you going to do? Do you have a 1d to test against it?
Wait...3 sec shutter speed? I wonder if that has a bearing on anything...just hinking im going to try some tests myself now.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: altenae on April 02, 2012, 05:21:37 PM
How dark is 2.8 @1600 ISO with 3 seconds exposure ??
Just a question, but what do we expect from the AF with this kind of darkness ??
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bob Howland on April 02, 2012, 05:31:52 PM
How dark is 2.8 @1600 ISO with 3 seconds exposure ??
Just a question, but what do we expect from the AF with this kind of darkness ??

I was wondering that myself. Using an Excel application just downloaded from the Internet, it is EV -2.6, which is less than the lower limit specified by Canon. I really wish that somebody would check this, though. There are bunches of charts on the Internet, but most assume a constant ISO of 100.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Kernuak on April 02, 2012, 05:39:08 PM
Is this the one you are talking about:

http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml (http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml)

edit: this is for the 1DX, but it is helpful as well:

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12 (http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12)
No it wasn't, I haven't seen that one, I'll have to have a read later in the week.

The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.
That is helpful information. If you find the link back that would be sweet.
This link has good info at the Canon learning center.
http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article (http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article)
The AF system starts on page 4, with the bit I was referring to on page 5.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: itsnotmeyouknow on April 02, 2012, 05:39:34 PM
How dark is 2.8 @1600 ISO with 3 seconds exposure ??
Just a question, but what do we expect from the AF with this kind of darkness ??

I would say too much!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 05:43:45 PM
I just can't make my camera have problems like you describe, but yea, who handhold focusses 3 sec long and expects the camera to take less than a couple seconds to focus, not me.
The only thing i check for focus speed or if i want to reset it is to wing the focus ring way outta focus in which case a lot of cameras will struggle with what do do in those darker situations whereas in good lighting it moves the elements quickly into place. Between the 70-200 and the 50f1.2 getting to a place of focus takes much longer on the 50f1.2 but then the barrel focussing is so precise it must move on a much smaller threaded motor. I think of like the 85 and 50 f1.2 as going from a normal thread screw on most lenses to a super fine threaded screw that takes a lot longer to thread a nut on. Once i have things in focus within a general area the focus snaps to the next thing.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on April 02, 2012, 05:46:43 PM
Is this the one you are talking about:

http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml (http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml)

edit: this is for the 1DX, but it is helpful as well:

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12 (http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12)
No it wasn't, I haven't seen that one, I'll have to have a read later in the week.

The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.
That is helpful information. If you find the link back that would be sweet.
This link has good info at the Canon learning center.
http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article (http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article)
The AF system starts on page 4, with the bit I was referring to on page 5.
I don't know which article you are referring to as page 4...The link i provided had several articles on it.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: DavidRiesenberg on April 02, 2012, 05:52:12 PM
Yeah, it's very dark but I just tested it myself and I found it very situational. When it did manage to focus, it did it in about 1-1.5s. But it was extremely hard to find something with enough contrast to even achieve lock. The room was lit by and LCD screen btw which cast a pretty even dim light. As a contrast, AF was as quick as ever when I aimed it at charger LED. Lens was 50mm f/1.2
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bob Howland on April 02, 2012, 05:58:45 PM
FWIW, I found the LV calculator I used here:

http://www.pentaxforums.com/forums/photography-articles/88197-excel-2003-lv-light-value-calculator.html (http://www.pentaxforums.com/forums/photography-articles/88197-excel-2003-lv-light-value-calculator.html)

I compared its output, at three different sets of values, with the table on Wikipedia Exposure Value page and they agree.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mt Spokane Photography on April 02, 2012, 06:01:11 PM
Mine so far focuses instantly in low light, but I've only been using the default center spot.  My 5D MK II was also instant, but a hair slower, and the 5D MK II was one of the fastest low light AF bodies around.
 
I did turn off all the lights in my studio and verifying that it would not AF, then as I added light so that it needed ISO 102000 to focus at 1/60 and f/4, it took 3 or 4 seconds to AF.  As the light became enough to use ISO 25600, focus was fast.  I was using my 135mm L to test this.
 
I haven't tried the AF assist light on my 580 EX II, because it did not need it in what I considered to be extreme low light.  I'm wondering if the issue might have been related to the flash unit.  I'll try mine again tonight and try to duplicate your problem, it would be good to know if something is triggering this, or if your AF has a problem, or if mine also has a issue that I did not see. 
 
I do lots of extreme low light photography in near darkness and focus is perfect and fast with my MK II, so focusing in very low liight is a must for me.
 
 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 06:04:13 PM
How dark is 2.8 @1600 ISO with 3 seconds exposure ??
Just a question, but what do we expect from the AF with this kind of darkness ??

It was pretty dark :)  It was my basement.  I wasn't shooting in an environment that dark the other night.  Lighting was spotty though ( literally, with lot's of mini-floods creating mood ), so I'm sure some spots were darker than others.

Anyway, my the point of the original post, was in dark situations, the 5DII focused as fast as the 5DII, and I was kind of hoping for some improvement.  As well, switching from single AF point to the expansion or vice versa didn't seem to make much difference under those dark conditions.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Kernuak on April 02, 2012, 06:04:37 PM
Is this the one you are talking about:

http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml (http://learn.usa.canon.com/resources/articles/2011/1dx_af_pts_article.shtml)

edit: this is for the 1DX, but it is helpful as well:

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12 (http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml?categoryId=12)
No it wasn't, I haven't seen that one, I'll have to have a read later in the week.

The article I was thinking of was actually for the 1D X, not the 5D MkIII and isn't specific, but it states that you shouldn't use single point spot for low light (which is irrelevant to this thread and obvious to most of us anyway) and that point expansion is to improve tracking. Reading between the lines, it suggests that point expansion shouldn't be used for slow moving/stationary targets. So while it isn't clear, it's suggestive that single point is the best option for low light. Of course, whether that makes it it any quicker isn't guaranteed.
That is helpful information. If you find the link back that would be sweet.
This link has good info at the Canon learning center.
http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article (http://www.learn.usa.canon.com/dlc/search/search.spr?keyword=Rudy%20Winston&filterBy=Article)
The AF system starts on page 4, with the bit I was referring to on page 5.
I don't know which article you are referring to as page 4...The link i provided had several articles on it.
Sorry, I was referring to the article I forgot to link to.

http://cpn.canon-europe.com/content/education/technical/eos_1d_x_explained.do (http://cpn.canon-europe.com/content/education/technical/eos_1d_x_explained.do)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 02, 2012, 06:10:04 PM
Mine so far focuses instantly in low light, but I've only been using the default center spot.  My 5D MK II was also instant, but a hair slower, and the 5D MK II was one of the fastest low light AF bodies around.
 
I did turn off all the lights in my studio and verifying that it would not AF, then as I added light so that it needed ISO 102000 to focus at 1/60 and f/4, it took 3 or 4 seconds to AF.  As the light became enough to use ISO 25600, focus was fast.  I was using my 135mm L to test this.
 
I haven't tried the AF assist light on my 580 EX II, because it did not need it in what I considered to be extreme low light.  I'm wondering if the issue might have been related to the flash unit.  I'll try mine again tonight and try to duplicate your problem, it would be good to know if something is triggering this, or if your AF has a problem, or if mine also has a issue that I did not see. 
 
I do lots of extreme low light photography in near darkness and focus is perfect and fast with my MK II, so focusing in very low liight is a must for me.

Yeah, I've never had much of a problem focusing with the 5DII either, I was just having problems at the venue acquiring focus in low light, and was getting the exact same result with both cameras... and was just expecting better results with the 5DIII for low light.

Maybe there are three tiers - good light, low light, crazy dark, and the 5DIII does better in the first two and is equivalent in the last?

Anyway, food for thought, I'll play around more later.

I know for a fact that one shot I COULDN'T lock onto quick enough was ISO 1600, f/2.0 and 1/13 shutter speed.  I know this, because I accidentally had the camera on Aperture priority instead of manual, and it came out blurry ;)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: helpful on April 02, 2012, 06:12:46 PM
This is not what I am getting. I shot an inauguration on Friday with the 5D3 and autofocus was insanely perfect and snappy down to exposures of 1/30th at f/2.0 at ISO 12,800 with the 135mm f/2.0L.

I also shot a track meet that ran until 1030 pm under poor stadium lights, and tracking was right on, even with runners going in and out of the uneven beams of very dim lights, or backlit in the curves of the track.

The AF of the 5D3 is absolutely incomparably better than the 5D2, and I have loads of experience to be able to make this statement.

BTW, I am using the automatic focus tracking which uses the center spot to lock on and then tracks it to any of the other 61 AF points. It is the mode that shows up with a border around all the AF points and a bold center point, when you are selecting autofocus modes. (I am describing the view through the viewfinder.)

Also, AF worked just as well even if I selected the initial focusing point as one of the other ones rather than the center.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: RunAndGun on April 02, 2012, 06:42:00 PM
I was sitting in my office one night last week with only one desk lamp on and i was able to achieve FAST focus lock with center point, single shot, 70-200 f/2.8 v2 on almost anything I pointed the camera at.  I was nailing focus shooting into my walk-in gear closet with no lights on in it.  It seemed like as long as there was a least a TINY bit of contrast on the object, it would lock-on and be in-focus.  This new focus system is worlds better than the MKII's system.

The MKIII, especially the focus system, seems to be very polarizing.  People are either singing it's praises and loving it, or they're saying it's junk...  All I can speak to is MY experience with MY copy of the MKIII, and so far it has performed admirably for ME.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: LetTheRightLensIn on April 02, 2012, 07:11:06 PM
How dark is 2.8 @1600 ISO with 3 seconds exposure ??
Just a question, but what do we expect from the AF with this kind of darkness ??

It was pretty dark :)  It was my basement.  I wasn't shooting in an environment that dark the other night.  Lighting was spotty though ( literally, with lot's of mini-floods creating mood ), so I'm sure some spots were darker than others.

Anyway, my the point of the original post, was in dark situations, the 5DII focused as fast as the 5DII, and I was kind of hoping for some improvement.  As well, switching from single AF point to the expansion or vice versa didn't seem to make much difference under those dark conditions.

I think it was said tht you used the 85 1.2, isn't that supposed to have very slow AF and a massive focusing element to move? Perhaps it was already moving full speed wth the 5D2 (or maybe it needs 1 series battery power to move faster?)   I don't know, but just tossing that out there.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Sycotek on April 02, 2012, 07:41:51 PM
If it hasn't been said already - take the assist points off - the fastest af point (and the correct af mode in that situation) is the standard single af (not precision spot af) assist points is best used for AI Servo on a moving object. Especially if you are running the 1.2 lenses wide open assist point will only slow the entire af system down as it is trying to feed data to and from the center point.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: cpsico on April 02, 2012, 07:46:15 PM
The auto focus is complex, there is a learning curve. I have tested a 5 d MarkIII AF was lightning fast
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: BobSanderson on April 02, 2012, 08:49:26 PM
It was dark, you had it set right and it failed you. Shizam1, perhaps you and Mrs. Shizam1, should simply return that camera (or use it under different conditions) and continue to shoot with the two Mark IIs that have brought you all your wealth and acclaim. It seems many have tried heartily to solve your problem to no avail. 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mt Spokane Photography on April 03, 2012, 01:10:38 AM
I do a lot of low light shooting with my 5D MK II, and tried out my 5D MK III with my 35mmL, 50mm f/1.4, 85mm f/1.8, and 24-105mm f/4  in various levels of low light.  Obviously, it takes longer to focus in extreme low light, but, as noted, something is going on that seems different.  I see the lens focus, and the shutter will then operate, but the AF achieved light delays 1/2 sec to 1.5 sec after focus is apparently achieved.
 
I tried some different settings, changing to shutter release priority, etc, but it still delayed before the focus light flashed.  I'm thinking that the camera is making a fine adjustment or refining the AF, but if the lens moves in 1.5 sec in extreme low light, the focus light delays before it illuminates.
 
The 50mm f/1.4 achieved focus and released the shutter in about 1 second, which was faster than the other lenses, it does not have to move far, but it was a suprise to see the big difference.  The other three lenses took about 2 seconds in very low light 1-1/2 seconds for the shutter to release and just over two seconds if I waited for the light.  I did not see a difference in sharpness, but then, to even get a image n low light like that, I was using ISO 51200 at f/4 and 1/60 sec or 1/50 sec at f/1.8 and ISO 6400.
 
 
Merely low light was no problem, but shooting in extreme low light was no a whole lot different than the 5D MK II.
 
So, all I can say is press the shutter fully, and it will operate when focus is achieved.  If you half press and wait for the AF light to flash, it will take longer.
 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Jared on April 03, 2012, 03:54:51 AM
Hi everyone,

Apologies if any of this has been covered throughtout the rest of the thread but I thought I'd clarify some uncertainties I came across:

1) The 5D2 can only utilise AF-point expansion to the 6 additional points in AI-Servo mode AND whilst the center point is selected. It does NOT work in One-Shot!

2) Using the AF-assist (red) light on any speedlite will slow the AF dramatically. If you need speed, turn it off in the custom functions (only the 5D3 can do this, of the 5D bodies - I think this previously was only a 1-series feature - correct me if I'm wrong). This will obviously have the trade-off that you'll have trouble locking onto low-contrast (eg. plain colours with little or no texture)/low exposure value subjects.

3) The AF-assist beam from a 580EX II will not cover all the AF-points of the new 61-point AF-system. I don't know off-hand the extent of coverage to the outer points - it was in the 5D3 manual.

4) The AF-assist beam puts out an array of red vertical stripes to introduce contrast for horizontal line AF sensors to be able to lock on

5) Further to point 4, using the spot AF point mode reduces the area for phase detection and hence isn't recommended for use in combination with the AF-assist beam as it reduces the likelihood and speed of locking on.

6) Fast primes often take longer to focus as accuracy is critical, as one can imagine when the lens may be being shot wide-open

7) My 85mm f/1.2 II is actually quite fast. You just need to know how to use it: turn off focus hunting in custom functions (I always have it disabled) and secondly if you manually pre-focus the lens to an approximate distance to your subject it will be quick at locking on. If the lens is used in AI-Servo the incremental adjustments when tracking a subject are actually quite fast. You just don't want to rack/hunt from one end of the range to the other when shooting action if you can help it.





Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Mr Simpleton on April 03, 2012, 04:13:19 AM
Did some further testing with the Mk3 and 70-200/2,8ISMk2, my gut tells me things did improve by removing and re-inserting battery, and this with lights even lower! And what may make comparing with the older Mk2 difficult is that the size of the AF point is likely to be much smaller in the MK3. After rebooting camera, I had no problems with fast and "snappy" AF in single shot, but with slightly less contrasty objects it did stop to "think for a while", not just hunt, runs the USM stops AF and nothing happens for say ~1 second and then AF confirmation. The Mk2 may have "seen" the object with high contrast (this was a wee bit off center), and locked on that when pointing at a slightly less contrasty area...

So so far my findings are: Yes there are "issues" with the 5D Mk3, it was really funky with my 200/2IS, and camera had all sorts of lock-ups/unresponsiveness when changing back to my 70-200. This was solved by re-boot of camera. Now the low light snappy AF may be an issue too... further testing has to be done. But it seems all is related to f/w and probably will be fixed in f/w upgrades (as it seems to correct after removal of battery).

I find that once camera has locked, the focus is dead on.... no worries that it misfocus! Not that I had any issues with my Mk2 either... but tracking AF is great, much improved over the Mk2. And I find that I can lock foucs in roughly 2 stops lower light that the Mk2, sweet!
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: shizam1 on April 03, 2012, 10:07:17 AM
Obviously, it takes longer to focus in extreme low light, but, as noted, something is going on that seems different.  I see the lens focus, and the shutter will then operate, but the AF achieved light delays 1/2 sec to 1.5 sec after focus is apparently achieved.
 

Yeah, I noticed that as well.  It would seem to focus, and then hesitate for a period of time before signalling that focus had been achieved.  Maybe double checking?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: kevinhan on May 31, 2012, 11:09:00 PM
I came from a 5d2 and also notice the same thing about my 5d3. Single shot AF with center point is noticeably slower than on the 5d2.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Axilrod on May 31, 2012, 11:21:25 PM
Ok I played around with my 85 for like 15 minutes going between spot and point area expansion and both of them locked on pretty quickly, definitely not a couple seconds.  The 85 isn't a very fast focusing lens of course, but it's definitely faster on the 5DIII than the II.  The only time the focus was very slow was in live view mode, but through the viewfinder it was very fast.  If this was your experience with the 5DIII you may want to play around some more, even after 2 months I'm still amazed by how often the camera just nails the focus.  Especially in Servo mode with fast moving subjects, but one shot is a walk in the park.  In my mind comparing the AF between the II and III is like a joke, I feel like the 5DII might as well not even have AF after using the III. 

I wouldn't be too discouraged, it may just be something minor.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: pwp on June 01, 2012, 01:52:08 AM
Frankly I'm astonished with the AF on the 5D3. It's quick and accurate right out to the outer points. And that's in One Shot or AI Servo. In low light it it genuinely knocked my socks off...but then I'm coming mainly from 1-Series experience. The Mk4 AF is easily confused in ahem, gentle lighting.

At risk of repeating what others have been saying, the sheer accuracy of the 5D3 AF has given new flexibility to the use of very wide apertures. Shooting handheld at f/1.4 has always been a bit hit & miss, just a minute sway of the body will shift focus enough to lose your focus point enough to junk the shot. Every new Canon that's come out since the 1Ds I've wanted to trust AI Servo in close f/1.4- f/2.8 portrait situations to keep track of my essential focus point. And it looks like the 5D3 is the first in my generally rough & ready experience to punch through with this ability.

PW
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: LetTheRightLensIn on June 01, 2012, 01:55:14 AM
Ok I played around with my 85 for like 15 minutes going between spot and point area expansion and both of them locked on pretty quickly, definitely not a couple seconds.  The 85 isn't a very fast focusing lens of course, but it's definitely faster on the 5DIII than the II.  The only time the focus was very slow was in live view mode, but through the viewfinder it was very fast.  If this was your experience with the 5DIII you may want to play around some more, even after 2 months I'm still amazed by how often the camera just nails the focus.  Especially in Servo mode with fast moving subjects, but one shot is a walk in the park.  In my mind comparing the AF between the II and III is like a joke, I feel like the 5DII might as well not even have AF after using the III. 

I wouldn't be too discouraged, it may just be something minor.

I wouldn't say the 5D2 AF is necessarily a joke when talking one shot center point. Indoors in a bright kitchen at night 5D3 did have a quite better hit rate than 5D2 with a 24 1.4 at 1.4 in two tests. But in a super dark room at night they basically had the same hit rate, 5D3 not better at all, both missed about 25% of the time by a fair degree, the absolutely 100% dead on rate was some deal lower than that, very tricky subjects and conditions though.

Overall the 5D3 is solid for one shot, sometimes noticeably better other times about the same rarely a trace worse than 5D2.

The 7D is the one that gets dusted by both for super low DOF fast aperture one-shot accuracy. Both my 5D2 and 5D3 easily beat it. 5D3 has best one shot out of 20D,40D,50D,7D for sure and better than 5D2 also, although only in some circumstances is the difference to any noticeably degree.

The 7D and 5D3 can drive AI Servo on 300 2.8 quite a bit faster than the 5D2.

I actually find the 7D, for soccer, so far, doing worse than the 5D2, once by quite a lot. It seems like the 5D3 will be the best, although the 5D2 can actually track quite well at times so long as the players are not really close and moving in certain ways (I also find my 5D2 does soccer radically better when the hidden AF assists are turned on, if you leave them off, then it suddenly does no better than an xxD at best in my experience; when players are not too close the 5D2 can almost do soccer as well as 1D2, when they are very close and moving fast then it seemed to get beaten by the 1D2 for sure) and I did notice the 5D3 do a few super weird things, like tracking a goalie slowly jogging out to toss out the ball with AF points kept totally on the goalie the whole time and a few times for one frame it suddenly grabbed the background stands at least 40' behind before jumping back perfectly on track the next frame, there was absolutely zero reason for it to have done that, very, very odd. It also once slightly missed initial focus but then instead of correct properly it someone jumped to like 5' in front of me to grab a railing only fractionally in the bottom of the frame and not even near any AF point.  Sometimes it would slightly lag behind or jump ahead of a player too, although mostly the frames were still usable if not really quite what they should be but then again with the other cameras those misses were usually enough to make the frame unusable. When it did suddenly jump way out of wack the next frame was always perfect, with the others sometimes the next frame would be a touch off still.

I really need more time with all of them for soccer though to really say, lighting can make a huge difference and the shooting circumstances and lenses were not always the same so far. And one game is hardly time to fiddle with all the settings. I basically just left it on default soccer mode.

7D seemed pretty decent for surfing though.

Sometimes the 5D3 doesn't really seem to AF any better than the 5D2 although other times it does (talking about keeping AF to center point, certainly if you go away from center point then it's much better 90% of the time). It seems to AF better than the 7D and xxD. So I'm pretty sure it will be the best of all the non-1 series, with the 5D2 for many situations the next best. How much better overall than the 5D2 I can't quite say yet. Sometimes it has seemed to do quite noticeably better, other times just barely matching the 5D2 (but given that I have yet to hit any circumstance with the 5D2 seeming to ever do noticeably better than the 5D3 and I have sometimes hit upon the reverse, it seems clear the 5D3 is better, hard to say how much yet though).

Interestingly, it was in the most brutal lighting and subjects of all where the 5D2 seemed to give the 5D3 a run for it's money with 24mm 1.4 shooting. The 7D did way worse in that situation than either.

In low because it's indoors but a well lit room nonetheless the 5D3 seemed to pull a fair amount ahead of the 5D2 with 24mm 1.4 shooting. In this case 5D3 was kind and then 5D2 next but noticeably behind and then behind the 5D2 were 7D and xxD at the back of the pack. So with somewhat better but still night indoor lighting the 5D3 pulled ahead but not at all when the lighting was truly abysmal indoor type.

Both those tests were center point only.

5D2 outer points fail to lock on many subjects which can be annoying, 5D3 ones tend to lock. Having compared accuracy when both lock yet though. My feeling was the 5D2 and 7D had a bit more accuracy when the outers locked than the 20D,30D,40D,50D although the 40D,50,7D would lock much more easily, especially the 7D, than the 5D2 outer points.

Need to use it a fair amount more to really say.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: pwp on June 01, 2012, 03:57:54 AM
5D2 outer points fail to lock on many subjects which can be annoying, 5D3 ones tend to lock.

"5D3 ones tend to lock"... True. And they tend to lock accurately. The old 9 points array used to give a me a lock on the outside points, but it far too often turned out to be wrong. Not wrong enough to see on the camera monitor, but wrong enough to dump at the sorting and ranking stage. It didn't take long to only trust the centre point.

PW
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: jordanbstead on June 01, 2012, 04:34:21 AM
i have been under the impression that the primes are not fast auto focusing lenses. i dont have any yet but i have worked with plenty of people who have. i have especially heard the 85mm L is a bit of a dog with AF. i'm on the fence right now about incorporating them into my work but even if i do i cant see myself not continuing to rely on the 24-70 and the 70-200.

i wonder if a more accurate test of the new AF system might be performed using the 70-200mm F2.8L? anyone have more experience that could enlighten us on this matter?

The 85L has a different focusing system than any other Canon lens, and is notoriously slow.  No one buys one for fast AF.  And primes are known for the fastest AF.  Take the 135L, for example. 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: wockawocka on June 01, 2012, 04:42:03 AM
My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body.  I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it.  For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4.  I lost many good shots because the 5DIII took 2-3 seconds to focus.  I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ).  For AF, I had "one shot" selected, and the center point with the 4 surrounding points.  I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some.  The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus.  The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60.  Oh, and I had a flash on, putting out that red focus assist as well during all this testing!  Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same.  I've also seen people post results of miraculous AF improvement with the 5DIII...

FIRST thing you do is disable the red AF assist light. That's what's causing your delay. You shouldn't need to use it at all. (Which is why I think the ST-E controller (new one) doesn't have the light on it).

You shouldn't need AF assist until at the very least ISO6400 - 1/60 - 2.8
Remember too, despite realising it you will be moving, your subject will be slightly and yet the AF light is slower and relies on static objects. The 5D3 AF system can AF in full moonlight, you don't need it.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: jonathan7007 on June 02, 2012, 10:37:08 AM
Coming later to this thread, I decided to add a reply here because there is so much good information in the older messages. I hope everyone read all the posts. Well, I should say I am glad I read all the posts because there are good suggestions to try when facing [apparently]slow auto focus on their Mk3's.

...because I am one of them.

I have had some good conversations with Canon. I am a professional photographer who will use the body for paid work when back home from this long personal travel, so I have to sort this out.

I have tried the camera with the lenses I have with me: 85mm f1.8, 24Lf1.4, and the 24-70mm The 24-70 has some kind of problem with focus motor and is going to Canon this morning. But even with the others there were delays. I KNOW this isn't the result of careful testing, just a description of my experience in the moment. I am adding a tile to the mosaic of shared experiences with the 5DMk3. I have been shooting with a 5DMk2 for a while. That body is at home.

I have spent several nights shooting with the 24 and 85 in a dark bar where local musicians get together to jam. I am sometimes pretty close. Not a concert -- the lighting is way lower than stage illumination. Some fluorescent light, too. I plan to use this body at wedding receptions, for example, and the challenge will be similar. I too had delays getting any confirmation of focus, and I was set up to require confirmation before shooting. Perhaps I will try allowing the camera to shoot before confirmation but it seem like a bad idea. I tried switching back to manual focus and it seemed more fluid and quick to get shots! Yikes! I was also practicing constant movement of the chosen focus points to train my without-looking muscle-memory-touch.

So I will keep testing, but because I am 6,000 miles closer to Canon's Virginia repair site I may make them swap out my body. Maybe the new one will do all the same things and I will know what I have to do to adjust. But the OP had a similar experience to mine and although there are some excellent suggestions in the thread (which I just stumbled on this morning) I have to be confident in the body.

Thank, especially, to all those people who contributed their thoughts, suggestions, detailed experience with AF settings, and personal testing.

jonathan7007



Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Bosman on June 11, 2012, 10:45:31 PM
I have been shooting running events without focus speed issues for normal sports. I even just shot a triathlon and the bikers are flying way faster than a runner and i was able to lock on dead but due to multiple people and having to refocus quick I'd have preferred the 1dm3. For extreme sports i can shoot anything just not muliple quick changes to refocus on diff people at diff distances quickly. If i have time to switch from one person to the next i dont have problems with the focus locking. I just never thought i'd love shooting sports with my next 5d series camera. I love it.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: cpsico on June 17, 2012, 08:03:37 AM
My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body.  I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it.  For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4.  I lost many good shots because the 5DIII took 2-3 seconds to focus.  I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ).  For AF, I had "one shot" selected, and the center point with the 4 surrounding points.  I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some.  The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus.  The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60.  Oh, and I had a flash on, putting out that red focus assist as well during all this testing!  Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same.  I've also seen people post results of miraculous AF improvement with the 5DIII...
I can't speak for the other lenses but the 50 1.4 does tend to hunt in low light unless you use just the center point.
I have the 70-200 L is and it doesnt like low low light either, but let me say there is nothing bad about that lens!!! It can focus on my Mark III but its a little to slow for anything thats not going to stay put. The dimmer the light the harder it is to focus for any lens.
I will say my 24-70 2.8 is a hammer and never ever leaves me disapointed. My 16-35 never ever cries in a corner in bad light either. Some lenses are just better than others in low light it seems :)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: wickidwombat on June 17, 2012, 07:39:43 PM
My 16-35 never ever cries in a corner in bad light either. Some lenses are just better than others in low light it seems :)

I noticed that the other night shooting a band and wow talk about fast! I had bugger all light though so i was shooting at 12800 f2.8 to keep 1/100 sec

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: kevinhan on June 21, 2012, 11:36:36 AM
Made 2 videos comparing 5d Mark 2 and 5d Mark 3 low light AF. Accuracy and consistency aside, 5d Mark II locked focus noticeable faster.

Black cardboard target against white wall. White wall spot metered at 1/100 f2.8 ISO12800. Center AF point only. Procedure was to AF, wait for AF lock, then turn focusing ring to lose focus, AF again, repeat. Photo of target in live view: http://kevinhan.net/old/images/target.jpg (http://kevinhan.net/old/images/target.jpg)

5d2: http://youtu.be/zxkE53t7xyE (http://youtu.be/zxkE53t7xyE)
5d3: http://youtu.be/M0kaHN2uY2c (http://youtu.be/M0kaHN2uY2c)

You guys who say your 5d3 focuses instantly in low light, do you mean as "fast" as this?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bdunbar79 on June 21, 2012, 11:49:30 AM
Made 2 videos comparing 5d Mark 2 and 5d Mark 3 low light AF. Accuracy and consistency aside, 5d Mark II locked focus noticeable faster.

Black cardboard target against white wall. White wall spot metered at 1/100 f2.8 ISO12800. Center AF point only. Procedure was to AF, wait for AF lock, then turn focusing ring to lose focus, AF again, repeat. Photo of target in live view: http://kevinhan.net/old/images/target.jpg (http://kevinhan.net/old/images/target.jpg)

5d2: http://youtu.be/zxkE53t7xyE (http://youtu.be/zxkE53t7xyE)
5d3: http://youtu.be/M0kaHN2uY2c (http://youtu.be/M0kaHN2uY2c)

You guys who say your 5d3 focuses instantly in low light, do you mean as "fast" as this?

Instead of doing 1 test you could shoot with it for 4 years like I did.  Mark III wins hands down.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: kevinhan on June 21, 2012, 11:52:16 AM
Yes I've been using the 5d2 for 4 years too. My experience with the 5d3 was similar with the thread starter's.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: mccallew on June 21, 2012, 01:05:37 PM
Like the OP, I have the same slow focus issue at weddings. I have shot 5 weddings in the past 4 weeks with the Mk3 and used multiple settings, tried changing focus-release etc. Mk2 -- and even Mk1 -- are faster. Could be the particular body, but my second shooter's experience is the same. Hands down I prefer the Mk3 to the Mk2, but it's focus speed -- not it's accuracy -- leaves much to be desired. With decent light the AF has been rock solid for me, but like the OP at 5 wedding receptions now I've missed moments that I KNOW I would not have with he Mk2. That's frustrating. But, I guess, there is no silver bullet camera out there, and Canon continues to have AF issues even if they've addressed other supposed short-comings.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Z on June 21, 2012, 02:37:06 PM
My rebel often locks AF like lightning in low light.  I generally do a double-take and ask it "Really?!" - the result is usually an out-of-focus shot when viewed at large size.

I know I'm comparing 5Ds and Rebels here, but my point is faster isn't necessarily more (or equally) accurate.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: TAR on June 21, 2012, 03:04:06 PM
My rebel often locks AF like lightning in low light.  I generally do a double-take and ask it "Really?!" - the result is usually an out-of-focus shot when viewed at large size.

I know I'm comparing 5Ds and Rebels here, but my point is faster isn't necessarily more (or equally) accurate.

exactly same with my 7D..it locks focus at low light but image at 100percent really out of focus..not even close..so those videos are useless to me atleast..
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: SandyP on June 21, 2012, 03:21:16 PM
Not sure what's going on, at all, but in the last few weddings I've shot with the 5D3, it's far faster, far more reliable and far easier to shoot in more AF intensive situations than the 5D2 ever was. And I had the 5D2 since it came out and shot with it at countless weddings. I can finally stop using the center point only.


I haven't had time to really play with my AF settings to really fine tune them for each situations, but I have heard that it can make a big difference to be using it to it's full potential, rather than setting it one way and going from there.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bdunbar79 on June 21, 2012, 03:23:14 PM
Same here Sandy.  It appears as though users are getting mixed results though.  I'm not sure the cause of this, but it's interesting that after using the 5D Mk II so much, for me, I noticed the faster AF of the Mk III right away, in lower light.  Interesting.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Ayelike on June 21, 2012, 03:37:39 PM
I literally just read this post then turned the lights off and took a few shots in a dark room and my 5D3 was locking on very quickly, even in the dark corners of the room on low contrast objects. I've zoomed in all the way on the preview and they're in focus. That was using a 50mm f/1.4. ISO was on auto getting up to 16,000.

I got mine just last weekend so maybe the newer ones are better. Have you got the latest firmware?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Hugo Fisher on June 21, 2012, 04:52:08 PM
Four weddings in last month behind me and I have no problem at all with AF or anything else on my 5D mk3. AF is quick even in dark no light situations.

50/1,4 , 24-70/2.8, 70-200/2.8 IS II
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: muldereric on June 21, 2012, 06:04:01 PM
I got mixed results as well, but in think that has more to do with me struggling with the settings.
Compared to my old camera (400D) the 5d3 has lots and lots of options that can be altered to adjust the AF system. Still figuring out how everything works.
I am not up for doing wedding photography yet, but working hard on improving my skills. Practicing on concert photography mostly at the moment.
What I do miss though is the AF point being visible in the VF after focussing, but it depends on the program you are using.
Anyone got some tips for the AF settings? Like whether to use the full 61 AF points, or just go for center with expanding points etc.
Would love to hear what the pro's have to say about this :)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: mccallew on June 21, 2012, 08:42:49 PM
Playing with the Mk3 in low light some this evening at home, I can say that using the Mk3 + 85 f/1.2 + 600EX-RT focus will lock much fast if I disable the AF assist beam as an earlier poster mentioned. I am going to try this at my wedding on Saturday and see if it works better. There is hope... Low light no flash seems to not be an issue... with flash there seems to be one.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: kevinhan on June 21, 2012, 09:26:19 PM
Have you got the latest firmware?

Yes.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: pdirestajr on June 21, 2012, 10:04:22 PM
I believe the MAJORITY of focus related complaints are user error.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bigmag13 on June 21, 2012, 10:35:27 PM
My rebel often locks AF like lightning in low light.  I generally do a double-take and ask it "Really?!" - the result is usually an out-of-focus shot when viewed at large size.

I know I'm comparing 5Ds and Rebels here, but my point is faster isn't necessarily more (or equally) accurate.

here here!
No prob focusing with my 5d2.... hand held Zeiss 2/50 Makro @F3.5 1/125 iso 200

and just for thought, I do shoot weddings with this puppy.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: victorwol on June 21, 2012, 10:54:45 PM
No problem at all with my 5D MKIII, very happy with the AF, it even made the 85 L 1.2 II feel like a brand you machine, not it is fast focusing... which was horrible on the MKII
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: ramon123 on June 24, 2012, 01:44:25 AM
5D Mark III AF from what I've seen is incredible.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: kpk1 on January 02, 2013, 01:33:55 PM
Anything new ?
Even with the last firmware, 5D3  works the same bad way in low light. I still have de 5D2 and it locks faster.
Any answer from Canon ?
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: glongstaff on January 02, 2013, 05:09:14 PM
My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body.  I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it.  For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4.  I lost many good shots because the 5DIII took 2-3 seconds to focus.  I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ).  For AF, I had "one shot" selected, and the center point with the 4 surrounding points.  I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some.  The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus.  The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60.  Oh, and I had a flash on, putting out that red focus assist as well during all this testing!  Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same.  I've also seen people post results of miraculous AF improvement with the 5DIII...

Theres a lot of discussion going on at the moment about the AF and the 5DMKIII - look here http://forums.usa.canon.com/t5/EOS/5D3-AF-assist-beam-slower-focus/m-p/2277#U2277 (http://forums.usa.canon.com/t5/EOS/5D3-AF-assist-beam-slower-focus/m-p/2277#U2277)

also:  http://www.canonrumors.com/forum/index.php?topic=10275.0 (http://www.canonrumors.com/forum/index.php?topic=10275.0)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bdunbar79 on January 03, 2013, 01:12:38 PM
Even the 1D X will have some trouble in very low light.  You have to be reasonable.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: RLPhoto on January 03, 2013, 03:58:57 PM
My 5D3 is the best low-light AF performing camera I've used. It just takes some trial-error to get correct settings.

To get good focus in no light situations, AF assitbeam + 9 point AF expansion is a bread and butter great.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Radiating on January 03, 2013, 10:57:41 PM
My wife and I shot a wedding yesterday, we brought two 5DII bodies, and one 5DIII body.  I didn't bring out the 5DIII until the reception because I didn't want to use it for the critical stuff until I've spent more time with it.  For the reception ( private room inside restaurant ) we were using the 85 f/1.2L II, 35 f/1.5L and 50 f/1.4.  I lost many good shots because the 5DIII took 2-3 seconds to focus.  I tested focusing in the low light with all the lenses, and the results were similar ( well, the 85 was even slower, because that lens is just slow focusing ).  For AF, I had "one shot" selected, and the center point with the 4 surrounding points.  I couldn't easily do a side by side because I didn't have two of any one lens, but I did switch lenses between the bodies and played around some.  The 5DIII was as slow, or possibly even slower than the 5DII to achieve focus.  The amout of natural light in the reception was around ISO1600, f/1.4 and 1/60.  Oh, and I had a flash on, putting out that red focus assist as well during all this testing!  Anyway, just giving people a heads up on what I experienced, and I've seen some others post the same.  I've also seen people post results of miraculous AF improvement with the 5DIII...

You don't seem to understand how focusing works. So the point of the 5D Mark III is to improve focusing accuracy in good light such as sports. In situations with bad light you should use something like a 6D.

You're doing the equivalent of saying "man everyone says this Ferrari F430 is so great, but it can't even tow a trailer, what a peice of a junk!"
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: jonathan7007 on January 09, 2013, 09:55:55 PM
Radiating, your answer is a surprise. He reports slow or no focus in function room lighting, which many others have experienced. ...with the center focus choices. The 5D is said to have a good center focus point but rapidly lose in comparison to the Mk3 for any focus area except the center, and the 6D points are clustered closer to the center than the Mk3.
https://www.youtube.com/watch?v=0-lRkFQBlsQ (https://www.youtube.com/watch?v=0-lRkFQBlsQ)
About halfway through the video he took the 5dMk3 and a 6D (same lens) into a very dark room and compared their abilities.

I am not very happy with my 5dMk3 either but it's not operator error. Have a 5dMk2, also and have been doing this for a long time. Another pro here reports the same. I am NOT talking about AF-assist difficulties. There is something flaky about some of the bodies.

jonathan7007
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Apple Tree Studios on January 09, 2013, 10:46:15 PM
I love my 5DIII autofocus. I've shot about 100 weddings with 5DII bodies, and am on about 15th wedding with my 5DIII. I shot a few weddings on a Nikon D3s last year when I was considering a switch due to the not so good 5DII focus. I loved the Nikon D3s autofocus, but missed the ability to crop that I had on my 5DII, and the skin tones were nicer on my Canon. I decided to stay with Canon. I find the 5DIII faster and more accurate than anything I have ever used. I did a brief, non technical review with pics on my blog here: http://appletreestudiosblog.com/2013/01/04/canon-5d-mark-3-review-for-wedding-photography/ (http://appletreestudiosblog.com/2013/01/04/canon-5d-mark-3-review-for-wedding-photography/)

I will be getting another 5DIII soon, the 6D looks great, but I love the 5DIII autofocus. It also make shooting with two cameras easier if they are the same.

Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bvukich on January 10, 2013, 12:36:36 AM
For those having focusing speed issues, are you half pressing the shutter release, and waiting for the AF confirm beep?

If so... don't.  Try pressing the button all the way, the beep comes significantly after focus has already been successfully achieved on the 5D3 (so I've read, I don't have mine quite yet).
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Nishi Drew on January 10, 2013, 03:27:18 AM
Welp, I feel a lot better sticking with a second hand 5DII, that I already have and no problems. My biggest concern
if anything was with the 5DII AF but hey, it works, and looks like outside of shooting sports the 5DIII just has better sealed body and handles high ISO/banding a lot better~
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: AudioGlenn on January 21, 2013, 03:01:07 AM
I see this thread is NOT about the AF assist beam.

I just wanted to add my vote for super fast AF on my mk3 in dimly lit situations.  No issues with mine
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: dlleno on January 22, 2013, 03:45:44 AM
What does dimly lit mean?  What EV(100)?  For the life of me I can't figure out why results are not expressed in EV and compared to the 5d3 AF spec
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Razor2012 on January 22, 2013, 02:14:14 PM
I think the 5D3 does a great job in low-light conditions.  There has been a few times where it didn't lock on quickly because of poor contrast.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: dlleno on January 22, 2013, 02:44:37 PM
I think the 5D3 does a great job in low-light conditions.  There has been a few times where it didn't lock on quickly because of poor contrast.

down to what EV(100) number does it do well?  have you tested EV -1 or even -2 with different types of subjects, i.e. contrasts?  all 61 points?  just the cross-type points? with and without AF assist?

the subject of being disaapointed with AF during weddings has to be quantified in terms that we can compare with the published specs. 
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: bycostello on January 22, 2013, 07:47:12 PM
2-3 seconds.. something wrong either with the camera or the way u are using it...
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: East Wind Photography on January 22, 2013, 08:23:16 PM
Maybe try disabling focus priority on 1st shot.  That's fine for AI servo in good light but in low light the 5d3 uses a different focus mode for verifying focus before shutter release.  It is more like live view focus but using phase detect.  First shot focus priority does cause some delays.  If that works better for you, set  a custom mode for low light shooting.
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: dlleno on February 05, 2013, 10:17:57 AM
Guys we have some progress -- Canon has at least acknowledged a AF issue with 5D3 and 1DX bodies when AF assist is in use.  A firmware fix is planned!   nothing specific yet about the low light situation where there is no AF assist, but to the extent that the root cause is similar or the same we may see a silent fix to this problem as well

http://forums.usa.canon.com/t5/EOS/5D3-AF-assist-beam-slower-focus/m-p/13547/highlight/false#M1486 (http://forums.usa.canon.com/t5/EOS/5D3-AF-assist-beam-slower-focus/m-p/13547/highlight/false#M1486)
Title: Re: Shot wedding with 5DIII, dissapointed in AF
Post by: Studio1930 on February 05, 2013, 10:33:55 AM
That is good news from Canon.  I experienced a similar issue with my 1DX and an EX580II flash.  During my last outdoors senior portraits photo shoot, I noticed that my flash was struggling to give enough light for my shots no matter how much I cranked up the FEC or how close I got to the subject.  I had to do quite a bit of correction in post production.

A few days later I did a test with my 1D4 and my 1DX and I noticed that with the EX580II flash externally shot inside a softbox on a stick with radio poppers as triggers (always use them), the 580/1D4 combo exposed the scene perfectly and the 580/1DX was waaaaay inconsistent with many under exposed shots.  Switching back and forth produced the same results (1D4 was perfect and 1DX was way off).

I now need to figure out what settings or combos are causing this but for now I am shooting all off camera flash with the 1D4.  Glad I didn't buy that second 1DX and kept the 1D4.