Is my 5DII autofocus system defective?

Or is it just this bad?

My 5DII is an upgrade to my 40d I had previously. What I've found with the 5DII is that the autofocus system is terrible in comparison. It hunts a lot. Take for instance the following scenario.

Camera is on a tripod.
Lens has no IS.
Subject is static (mountains don't move fast enough to be seen with the naked eye)
AEB is on
Using cable release
All AF points enabled

Push button - camera completely refocuses before firing. Takes perfectly in focus scene, throws it out completely and focuses back again.
Push button for second AEB exposure. It does the same thing. It's like it completely forgot what it was doing.
Repeat, etc. etc.

I can try to direct it to a single AF point but it will do the same thing. This morning it seemed to error completely at one point by throwing the lens to close focus instead of infinity and refusing to try the other direction until I had manually focused it almost there. WTF?

I used to own a 20d, and this is theoretically the same AF system feature wise, right? The 40d could fire off a few dozen shots in the time it takes the 5D to focus 3 times on a static mountain.

What am I doing wrong? I knew the AF system was going to be a downgrade from the 40d but I did not expect it to just plain SUCK.

Aside from this I'm pretty happy with the new camera, since I do landscapes mostly...

-K

Something is wrong.

Set the camera to high speed continuous shooting mode. Then press and hold the shutter button until all three AEB shots have been taken. Then let go of the shutter button.

PacAce wrote in post #9161149
Set the camera to high speed continuous shooting mode. Then press and hold the shutter button until all three AEB shots have been taken. Then let go of the shutter button.

I going on an off between using mirror lockup, so this is not an effective option if you're trying to minimize vibrations.

-K

Something is seriously wrong. Have you tried it with a different lens ?

And don't turn on all the focus points.

kurt765 wrote in post #9161166
I going on an off between using mirror lockup, so this is not an effective option if you're trying to minimize vibrations.

-K

Are you talking about shooting a landscape under very low lighting conditions? If so, that may explain your focusing problem.

The most recent episode that I'm referencing here is in the vicinity of sunrise and after, yes, but there was plenty of light. I started shooting about 5 min before the sun actually came up and continued on for about 45 minutes. The point where it refused to focus to infinity was well after the sun came up. I've never seen a camera actively focus in the wrong direction repeatedly until I had to show it how wrong it was by focusing 90% of the way there manually.

I was using mostly the 24-105L and 70-300 DO but also the 16-35II this morning. The phenomenon of the camera forgetting where it was focused just now and not realizing it is currently in focus happens on all 3 lenses.

-K

kurt765 wrote in post #9161231
The most recent episode that I'm referencing here is in the vicinity of sunrise and after, yes, but there was plenty of light.

Were you shooting into the sun? Or someplace with no contrast?

kurt765 wrote in post #9161231
The most recent episode that I'm referencing here is in the vicinity of sunrise and after, yes, but there was plenty of light. I started shooting about 5 min before the sun actually came up and continued on for about 45 minutes. The point where it refused to focus to infinity was well after the sun came up. I've never seen a camera actively focus in the wrong direction repeatedly until I had to show it how wrong it was by focusing 90% of the way there manually.

I was using mostly the 24-105L and 70-300 DO but also the 16-35II this morning. The phenomenon of the camera forgetting where it was focused just now and not realizing it is currently in focus happens on all 3 lenses.

-K

Yes, the camera always does that with AFPS enabled. You can have the camera on a tripod and as long as you have AF selection set to auto, the camera will never pick the same AF points consecutively every time you press the shutter button. I don't know why it was designed that way but every time you press the shutter button, a different set of AF points will be selected for focusing. The best thing to do is for you to manually select the AF point. WIth a static subject like a landscape, I can't think of any reason why you'd want the camera to automatically select the AF points for you.

but i thought the OP said that it is the same even for a single point focus.

indeed I did

sounds like it is stuck in servo mode.

The whole time it was set to One Shot / fast motor drive

Is the 5D2 autofocus really a downgrade from my 40D?

I havent received my 5D2 yet... but If thats true I'm slightly disappointed...

well, i do not know why you feel disappointed, cause 5d mark II is around for few months and tons of reviews are avaible, and all specify that this is not a fast-focus camera. of course is precise, but not for hot-action-shots.