Shot wedding with 5DIII, dissapointed in AF

[Bob Howland]

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.

 

[Kernuak]

Is this the one you are talking about:

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

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

The AF system starts on page 4, with the bit I was referring to on page 5.

 

[itsnotmeyouknow]

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!

 

[Bosman]

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.

 

[Bosman]

Is this the one you are talking about:

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

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

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.

 

[DavidRiesenberg]

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

 

[Bob Howland]

FWIW, I found the LV calculator I used here:

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.

 

[Mt Spokane Photography]

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.

 

[shizam1]

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.

 

[Kernuak]

Is this the one you are talking about:

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

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

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

 

[shizam1]

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

 

[helpful]

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.

 

[RunAndGun]

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.

 

[LetTheRightLensIn]

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.

 

[Sycotek]

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.

 

[cpsico]

The auto focus is complex, there is a learning curve. I have tested a 5 d MarkIII AF was lightning fast

 

[BobSanderson]

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.

 

[Mt Spokane Photography]

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.

 

[Jared]

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.

 

[Mr Simpleton]

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!