Anyone else experiencing autofocus problems with thier 1DS3? Now on my third body, first 2 has focus issues and viewfinder alignment problems. Now the third body, (or is it body) seems to be behaving as the other two did. Using centre focus point only, and on static subjects, the camera seems to have problems focussing, mainly at longer distances. For example focus on something 1/2 km awy and it focusses 30 meters away, manually focussed things are rectified. This happens mainly on the 16-35MK2 set on the wider end, put it on 35 and it's ok. My 85 1.2mk2 exhibits similar problems, as does my 50 macro, however my 135f2 is perfect.

I never had these issues on my 1DS2 with any of these lenses, and quite frankly i want to throw the whole lot off a very high building!!! It's driving me nuts.

Any ideas, thoughts, Body or lenses or both?

Regards, Gary.

Hello Gary

John here from Australia.This is my first post also.I have had similar problems and have just left camera with dealer after he did testing and confirmed problem. It is wierd. I have set up on tripod to take shot of static object ... a 24"x36" sheet of newspaper ...with a
range of lenses...100m2.8 macro, 70/200 2.8 is ,85 1.2 ,50 1.4 and 24/105 4 NONE of them focus properly...this is when the centre focus , single shot AF mode is on. It is noticeably better when the servo tracking is on.. still not perfect...when the camera is set to live view and manual focus it works perfectly.I figure it is no use using the custom function to adjust lens because the focus is so different between servo tracking and single shot.I have tested it against another 1ds3 and 2 x 5d they are all much better. I would be very interested to hear of anyone else with focus issues.
Will let you know if Canon have anything to say when I get it back... soon i hope as I love it warts and all !

Cheers JOHN

No problems here - one of mine has just rolled over it's first 10,000 frames with out any problems.
A lot of the shots are on the fast 35, 50, 85 & 135 near wide open as well.

The second body is around 500 frames and though it's maybe early to tell - so far it looks good to.

So far I'm real happy.

Have you done a calibration test on your lenses ?

Hi David,

As John said, there is little point in calibrating the lenses as the problem is so spurious. The zoom works ok on 35mm but not at 24 and wider, the 85f1.2 is out by a long way at infinity, as is 50macro, and as calibration is only for tiny adjustment it seems completely crazy to expect this to fix a 'big' problem.

I am happy someone else is experiencing the same issues as myself, as after 3 bodies, and Canon saying 'we've not had any others come back with this problem', so either they are talking shit or i am the most unlucky 1DS3 owner around... i think the former, Canon's QC is a disgrace as far as i'm concerned and i wish i had stuck with my Phase back on a 'V' Blad which was ROCK SOLID.

Gary.

I just went out and shot a few pictures with my 16-35 II on the 1DsIII. I selected the center focus point and shot several images at 16mm of objects about 150 feet (50 meters) away to infinity. I then double checked the focus points in Canon Imagebrowser. I noticed that some shots at infinity left the the objects at 150 feet out of focus, while others were perfectly in focus. At 16mm, objects at 150 feet to infinity should all be in focus so the camera was focusing closer than that for some reason. Something is not right here. Will go out today and shoot some more and check again.

My test method is to tape a 24 in x36 in test sheet or newspaper flat to a wall , set the camera on tripod and adjust the distance between them so the sheet fills the frame.
I found the focus might look ok in the viewfinder it is blured when viewed on computer.
As I mentioned the strange thing is the differences between the autofocus methods.

Well, I went out and shot a bunch of frames trying to reproduce the OOF situation I found with one frame in my previous post. Focused alternately on objects about 200-500 meters away and on infinity. I could not reproduce the situation described so I wonder if this is a case of an occasional mis-focus that can happen with any camera. On the other hand, there could be a fault that only appears under certain conditions. Will continue to keep an eye on this...