5D MK II - Auto-Focus Opinion Needed

I don't know anything about specific 5D mkII focus issues, but I have seen a few reviews of the new camera which have suggested that Canon's AF needs speeding up in general , but not as an issue particularly for the 5D alone. I'm not saying there isn't a problem, but that sort of comment is all that I have seen and I have been looking at the reviews.
If that generic criticism is the issue, I think it is misplaced concern since plenty of people have been photographing action with Canon AF systems for quite a while now. Somebody else's AF may be somewhat faster, I don't know, but even the older EOS cameras work plenty fast for the photography most of us do.

Just as an historical note, back in the first reviews of the EOS (the 650 & the 620) cameras in Popular Photography in late 1987, it was observed that the EOS autofocus then was faster than manual focus by expert photographers with greater accuracy.

I have a 5D MkII and can tell you that the AF system works just fine under reasonable lighting conditions. Most important, it is accurate, which is more than I can say for my 30D. I don't know whether this is entirely made possible by the focus microadjustment calibration procedure, but I do know that every shot is spot-on. I couldn't get this kind of accuracy with the 30D despite the fact that I sent it in to Canon along with lenses for calibration. The 5D MkII AF seems fast enough to me, but I must admit that I don't frequently photograph fast-moving scenes in dim light. I shoot with f/4 zoom lenses (17-40, 24-105, 70-200) all the time and the AF system performs like a champ with them as well as with faster primes such as the 50/1.4 and the 85/1.2. The center AF is indeed more capable than the other AF sensors in difficult conditions where there is little contrast in the object you are aiming at, but I've not found this to be an issue in practice--I just use the center AF almost all the time and get the spot-on results I mentioned above. (Yes, I know that focus-and-recompose has its hazards, but even at f/4 it's not at all an issue at most shooting distances.) If you must shoot in (near) darkness, the red light emitted by a Canon flash or the ST-2E will give the AF system what it needs to lock on instantly.

Tom,
5DMKII AF is more than adequate for the conditions you describe.

I also own the 5D II. I think most of the comments you are seeing which mention AF are from those who were hoping for a bigger improvement in AF speed over the 5D. And, more cross-type AF sensors. Based on what I have read on hear and other forums, the Canon 1D series bodies have much better AF. I think people were hoping Canon would put their pro level AF in the 5dII.

Overall, I find it adequate as a center AF sensor camera.

"shoot portraits, parties, nightlife and architecture ... Should I not be concerned?"

I have had the MKII only a few weeks but based on my first few thousand shots, my anwser is "absolutely not!". The autofocus system on the MKII is excellent, certainly as good as the original 5D, and maybe better. I shot all kinds of sports with my 5D and never had any issues. The lens you use can perhaps make a difference so choose wisely.

http://www.digitaljournalist.org/issue0902/tech-tips.html

Scroll down 'til you find the question about the 5D II autofocus.

Yes for subjects in good lighting, the AF of the 5D II is fine. I can shoot birds in flight, no problem. It (AF of 5D II) seems to be a bit better than my significant other's 40D...

What you might want to read about is how does the AF of the 5D II fare in low(er) light conditions? Again, in bright light it is fine - but I don't use this camera to AF in low(er) light conditions. Others have and it is worth reading their comments.

rdc/nyc

I shoot almost exclusively in low light conditions of the theater. I've shot just about every Canon DSLR and until recently I used a 1DmkIII. I now shoot with a 5D2 and it autofocuses just as fast and tracks just as well as the 1DmkIII. I use a 70-200 f/2.8 L IS and some primes. I typically use the center AF point and the AF button to start the AF.

I have absolutely no problems with the 5D2 auto focus in low light.

I was concerned about the 5DII AF but it works very well indeed (at least with fast F2.8 or better lenses). I have shot lots of ski racing (a difficult subject for AF) and lost about 5-6 shots out of 1500+ for focus issues. In ski racing if you are shooting from on the course a skier passing you will cover about 100 degrees of arc in a second. I have also had no problem shooting amateur ice hockey in some fairly dark arenas. What I have discovered is that in difficult conditions you need to just select the center AF point - if you use the auto selection feature the AF does not perform too well. I have really only discovered one type of sjhot where a 1 series performs noticably better (I have been shooting film 1 series cameras for many years and still shoot with the 1V and 1NRS). If you have a fast moving subject suddenly appear the camera may not focus quickly enough. I discovered this by shooting a sucession of skiers going over a jump I was lying beneath. Since I could not see the skier until they were in the air above me the camera needed to snap into focus very quickly. Out of about 20 skiers only two were in focus - the 1V would have had about an 80% sucess rate. Of course in this situation the solution is simple - use manual focus! I beleive that most tests have the 5DII AF about the same as the 40D / 50D and slower than the Canon 1D series and Nikon D3. For what you are shooting you will have no problems - in an indoor setting my camera will usually manage to focus on a blank white wall (after a bit of hunting) which is a pretty good test of any AF system. You will be impressed by the image quality of the 5DII