UPDATE: I've received the replacement 5D3 and will report back after I've used it a bit to compare to the first body I had trouble with.
Curious to hear about your experience with the second body.
OK, I've used the camera a few times now but I didn't do much low light until tonight.Verdict: This 2nd 5D3 body AF WORKS.
Totally different experience. It works as I think it should. If the last camera worked like this camera, I likely never would have visited this thread for more than casual curiosity.
I've done nothing scientific or really anything different than the last camera. I just set the menu settings the same as my other cameras and used it like I use any camera. I used a 24-70 f/2.8L lens tonight. I also tried a 24-105 f/4L. Both worked virtually the same with regard to AF Lock in low light.
- ... what setting the AF Assist light was set to (either OFF or ON)
- ... whether a flash was attached or not
- ... whether the flash was turned on or not
- ... if it was a Canon flash or a Sunpak RD2000
- ... if I hold a beer in one hand, hold the camera steady with both hands, or balance the beer on top.
- ... Shot outside in dark front yard.
- ... Shot indoors available, dim and candle light.
- ... Shot the cat in dim room with 40W lamp distant backlight. (Because Northstar can't have all the fun with his front yard dog!)
- ... Shot a black rolly cart in the almost dark foyer (the Canon body contained inside cart is in focus, camera hand set on stair rail, 6 sec exposure, used 580EX-II AF Assist light)
The camera focused as I would expect in all cases. Nothing took longer than 2/3 sec except the almost dark rolling cart, it took about 1 sec with the AF Assist lamp on a 580EX-II flash. No ridiculous and maddening focus hunting.
If I try to get AF Lock in a semi-dark environment with AF Assist = OFF, the camera will either refuse to try (Focus Hunt = Off) or never AF Lock (Focus Hunt = On) which I consider normal. If I then turn on the AF Assist, it focuses in 1/2 - 1sec. I've also noticed that the AF Lock/Hunt/Red AF point red blink doesn't even happen if the focus hasn't changed. I wish it would still blink anyway.
So far this is only a few hundred shots in to this body. Some have complained that their camera started off fine and then suddenly got worse. All I know is it works better and gives a much better result than the 1st body and I am glad I exchanged it!
Thanks to this forum for helping me conclude that there are some folks that have had no problems and others that have exp. similar problems. I was pretty doubtful I would get a better replacement body but so far, I think I did!
Here are some small JPGs straight out of the camera SD slot, no changes whatsoever. Candlelight, 40W lamp in background and then very dark foyer using AF Assist lamp and then flash fired.