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5DII owners: defective autofocus?

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FlightDeck

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Hey all,

I bought a 5DII a couple months ago, used, about 2 years old, so among the first serials to market. I had some initial problems with it not being able to autofocus using the outer AF points when mated to an 85/1.2. At the time I thought it was the lens giving the camera a hard time.

I've since used the camera with a 17-40/4 and 70-200/4, both with and without 1/4x extender and B&H circular polarizers. The camera has AF problems with these lens too, even when using all-points AF.

When focusing the AF often can't lock on and it ratchets to full travel and sits there gronking away at the stop until it finally gives up. This occurs even in daylight conditions on very distinct contrast objects such as windows on a brick wall, large buildings / structures, people, etc. It was so bad on my recent trip that I had to give up on it several times and use manual focus.

Not that I mind MF, but this just doesn't seem right. Is the 5DII's AF really this bad? Or do I have a lemon that needs service on the AF sensor?

Edit: I forgot that I never had AF issues like this with the 20D and 50D. Both focussed quickly, rarely "hunting" for focus except in low light conditions.

--
Regards,
K
Ontario, Canada
http://photos.loneleaf.ca
(See my profile for equipment list.)
 
You bought a used and broken camera. I think you'll need to send it to
Canon for somme work.

My 5DMKII focuses very well thankyou.
 
before giving the camera for servicing, try cleaning the AF sensor that you can see when lifting up the mirror (mirror lock up) Clean it only with adapted / authorized tools to avoid to scratch it
If the sensor AF is dirty, this could be the cause

Quick and at no cost

If this does not work send the camera for servicing

BTW have you tried with several lenses ?

Robert
 
Nikon1977 said:
You could try cleaning the contacts on the camera. Also try changing C-Fn III-1 to focus search off to reduce the hunting.
Click to expand...
Thanks, I heard the same suggestion about the contacts over at FM, and will give it a try.

I tried the custom function you mentioned as soon as I encountered the issue. All it did was make the lens not do anything (since it can neither find a focus nor hunt).

--
Regards,
K
Ontario, Canada
http://photos.loneleaf.ca
(See my profile for equipment list.)
 
baobob said:
before giving the camera for servicing, try cleaning the AF sensor that you can see when lifting up the mirror (mirror lock up) Clean it only with adapted / authorized tools to avoid to scratch it
If the sensor AF is dirty, this could be the cause

Quick and at no cost

If this does not work send the camera for servicing

BTW have you tried with several lenses ?
Click to expand...
Thanks Robert, great tip for clearing the AF sensor. Something I never would have thought of, and someone over at FM recommended the same thing.

I've had these issues with all of the lens combinations mentioned in my original post.

I'm also thinking that the different AF point types used on the 5DII vs those in the 20D/50D may have something to do with it. On the shots where it refused to focus, it may be that the focus point were over incompatible edges or on items of low contrast. I'm going to study my images to see which ones refused to focus and I have to use MF, to see where those AF points were landing.

--
Regards,
K
Ontario, Canada
http://photos.loneleaf.ca
(See my profile for equipment list.)
 
Have a look on the canon website at the 'white paper' for the 5D and the 'EOS autofocus paper'. You probably already know most of it, but there may be a snippet that works and the canon guys will try to tell you it all when you try to return the camera anyway, so at least you'll be on a level footing when you talk to them and you'll know more than most store assistants.

Good luck
 
I had once the issue of a wet AF sensor
Cleaning it and drying it solved the problem

As fa ras the AF is concerned, the central AF is excellent especially with 2.8 or even less lenses with activated hidden AF points

BUT all the other lateral or diagonal sensors are rather poor in dim lightb or low contrast situations, especially an issue with AI SERVO

Just check if unsharp shots come from those sensors and tell us

I always use the central sensor and recompose with the exception of portrait at wide apertures where you can't

Robert
 
Don't try using the outer AF points unless you understand the horizontal or vertical orientation associated with each of them. The center AF is cross-point so orientation doesn't matter. It's very accurate.

Sal
 
Sal Baker said:
Don't try using the outer AF points unless you understand the horizontal or vertical orientation associated with each of them. The center AF is cross-point so orientation doesn't matter. It's very accurate.
Click to expand...
This is what I've encountered. I've been so used to the all-cross type of the 50D, that in transition to the 5DII the single-orientation points caught me by surprise. I think this is the reason behind the majority of the issues I've been encountering. I won't know for sure until I have some time to review some recent photos and do some more test shots.

--
Regards,
K
Ontario, Canada
http://photos.loneleaf.ca
(See my profile for equipment list.)
 
FlightDeck said:
Hey all,

I bought a 5DII a couple months ago, used, about 2 years old, so among the first serials to market. I had some initial problems with it not being able to autofocus using the outer AF points when mated to an 85/1.2. At the time I thought it was the lens giving the camera a hard time.

I've since used the camera with a 17-40/4 and 70-200/4, both with and without 1/4x extender and B&H circular polarizers. The camera has AF problems with these lens too, even when using all-points AF.
Click to expand...
See this thread and, especially the third paragraph of this post:
http://forums.dpreview.com/forums/read.asp?forum=1032&message=37708585

The performance difference between the outer points and the central point on the 5D/II is dramatic, especially with fast lenses. F/2.8 & f/5.6 capability doesn't sound like much, but in practice it is a lot more significant.
--
Its RKM
 
If you have not sent your camera back to Canon by now please do so. Sometimes it is better to just bite the bullet and send it in and get it fixed. You can spend a week or more searching around in the forums for an answer. But Canon can determine if you have a problem and fix it for you.

Please don't say you don't want to be without your camera for two weeks either because right now you have a camera that doesn't work!

Be sure to post back when you get your camera back from Canon.

John
--

Feel free to use any of these additional letters to correct the spelling of words found in the above post: a-e-t-n-d-i-o-s-m-l-u-y-h-c If you find any extra letters, please place them here for future use...
 
I just tried my 5DII and Sigma 50 f1.4 using the outermost focus point, by the reflected light of a desklamp - (read - pretty dim). I found it had no trouble focusing on a horizontal dark edge against a lighter background, but struggled with a vertical edge.

I don't remember the configuration of the outside A/F sensors, but if they are only vertical ( rather than cross-type) this would make sense.
--

Judge: ' This image may be better in black and white - perhaps even just black! '
 
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