Shot wedding with 5DIII, dissapointed in AF

[shizam1]

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.

[shizam1]

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.

[Sallivres]

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."

[msdarkroom]

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.

[shizam1]

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.

[shizam1]

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.

[Tim Larsen]

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.

[shizam1]

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

[Axilrod]

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. 

[JR]

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!!!

[rlarsen]

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.

[Daniel Flather]

With my 580's light my 5D3 can focus in total darkness, but I only ever use spot AF.

[PhilDrinkwater]

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.

[shizam1]

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.

[mrmarks]

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