Canon 40d not quite focusing properly

Badger UK

Badger UK

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Brian Ardrey
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I've seen a few things on here about front focusing and micro adjustment etc. but can't find anything about the 40d specifically.

I'm pretty sure that my 40d is front focusing. I realise there's no micro adjustment on the 40d so I'm wondering if there is anything that can be done.
 
Mine front focussed but only noticeably at long subject distances. It went back to Jessops shortly before warranty expired (I had thought it was user error at first).

They had two failed attempts to fix it & eventually gave me a 50D with me paying the difference.

If they'd sent it to CCR I bet it would have been fine.....

Phil
 
tikkathreebarrel said:
Could we see some test results showing this please?
Click to expand...

I haven't tested it formally. It's just that I seem to be getting a lot of photos not in focus. Obviously, it could be me, but I suspect it isn't. The results are consistent and I'm pretty sure it's the camera (or lens).

Here's a couple of examples of what I mean:

1.
A-and-L---042.jpg


2.
A-and-L---017.jpg


I think you will see that the ground just in front of the subject is where the sharpest focus is.
 
Need to know a lot more about the setting used to take these photos.

I too struggled a bit getting sharply focused pictures with my 40D but technique is all, and if anything is even slightly off the camera is mercyless in showing it up.

I can well see why there are so many "my EOS ** or *** is poor at focusing" threads come from.

David
 
Willid1 said:
Need to know a lot more about the setting used to take these photos.

David
Click to expand...

70 - 200 f2.8 L camera set to Aperture Priority on f2.8. I used a monopod if that's of any relevance at all.
 
Are the pics the full frame or crops, what focus mode, Ai servo single shot ?
 
alastair.b said:
one shot might be your problem if you are shooting at telefocal lenghts at f2.8 as the dof is small so a slight subject movement or you moving will cause the image to become oof, try shooting in ai servo and using different focus points instead of re composing and see what happens
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I pretty much always use the centre AF point and then recompose, so I think I will defo give a try the different AF points, good call.

However, I particularly chose the shots above because I'm confident the subject wasn't moving. So I'm pretty sure that A1 wouldn't have helped, but I will still be giving it a go. Thanks. :-)
 
Badger UK said:
70 - 200 f2.8 L camera set to Aperture Priority on f2.8. I used a monopod if that's of any relevance at all.
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40D is a rather strange animal. I could swear with some lenses and settings it would never miss the focus wide open unless I made an obvious mistake (such as accidentally turning the focus ring after AF). I would say these lenses are Canon 200mm f/2.8L, 70-200mm f/4L, 100mm macro at macro / portrait distances, and Tokina 12-24mm f/4 and maybe some others. Tracking the subject in AI-servo is a different issue: 40D miserably fails.

Some other lenses are a real nightmare wide open and even stopped down. Canon 50mm f/1.8 was my worst experience, my friends 70-200mm f/2.8L IS did a pretty bad job with dogs in the park, Sigma 24-70mm was awful, Canon 24-70mm f/2.8L improved significantly from 30D at 24-35mm but is still hit and miss around 70mm, magic drainpipe caused a lot of headache.

70-200mm f/2.8L IS or 80-200mm f/2.8L can be extremely sharp wide open. Try focusing with live view, see if you can focus sharply at all.
 
I'd get it checked out by Colchester Cameras. With mine I kept noticing tips of noses were in focus when I had definitely aimed for the eye. Taking a similar shot to one of yours with a 300mm lens of a girl on a beach at a distance, focus was several feet in front of the subject. Have you any other bodies to compare? I eventually convinced myself it was the camera at fault when I had much more consistency with the same lenses on other bodies.

Phil
 
40D's do have a focusing issue, two of my friends have sent them off to be re-calibrated and they are much better now!

I'd ask where you bought it from whether they can send it off, otherwise, contact Lehmanns in Stoke On Trent and maybe arrange through them!

Regards,
Carl.
 
Badger UK said:
I pretty much always use the centre AF point and then recompose,
Click to expand...

Did you use the monopod for that? As whilst you pull back (assuming) to recompose the shot, you will be moving the plane of the camera (unless you have a ball head on the monopod, but still the same problem to a lesser degree).
Try one without the recompose.
 
Have a look at this

http://visual-vacations.com/Photography/focus-recompose_sucks.htm

Diagram is not brilliant but the text explains it quite well. Doesn't take much to see a 200mm at f2.8 (on a crop body??) will have similar problems.

The advice at the bottom about using the other focus points is I think very valid here. Difficult to do quickly but worth it.

Also remember the actual focus sensor area is quite a bit bigger than the square in the viewfinder so it's possible for it to pick up something other than your intended point.

HTH

David
 
I've had problems with a sigma with known front focusing issues.
had it recalibrated and it's pretty good now
my 40D is good but not perfect. firstly make sure the AF sensor is clean at the base of the internals.
also which autofocus point is being used on those shots? you can highlight it on the LCD on the back of the camera. it's in the options.
I would use the centre focus point only for that shot. DOF is so thin

the 2nd shot, her face seems out of focus, but the shoes look pin sharp. so what shutter speed etc?
 
Chaz Photos said:
I mean you can save image with the dot so we can see it
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But if you half press to focus then recompose and take your shot, doesn't the red square just move with the frame and so it could be (in the saved image) actually pointing at something else.
 
tiler65 said:
But if you half press to focus then recompose and take your shot, doesn't the red square just move with the frame and so it could be (in the saved image) actually pointing at something else.
Click to expand...

dont know not try it how about you look if that is what you did
 
daugirdas said:
Tracking the subject in AI-servo is a different issue: 40D miserably fails.
Click to expand...



Hmm. This makes me think I've been lucky with mine. I've not had a visible problem with any lens front or rear focussing or with AI-Servo failing. Guess I'd better count my blessings.
 
tikkathreebarrel said:
Hmm. This makes me think I've been lucky with mine. I've not had a visible problem with any lens front or rear focussing or with AI-Servo failing. Guess I'd better count my blessings.
Click to expand...

Try photographing someone walking towards you (I am not even saying running :gag:).
 
tiler65 said:
But if you half press to focus then recompose and take your shot, doesn't the red square just move with the frame and so it could be (in the saved image) actually pointing at something else.
Click to expand...

Correct. It tells you nothing.

Fragglerock said:
You could do some test shots with a more controlled environment.

eg.
http://regex.info/blog/photo-tech/focus-chart
Click to expand...

Don't use that test, or anything similar. It will lead you astray.

You need to do some controlled tests. Lots of good info on this link
http://www.talkphotography.co.uk/forums/showthread.php?t=166932
 
alastair.b said:
i know people who use a 40d to track lowflying jets and it seemed to cope pretty well? :shrug:
Click to expand...

Subjects moving across the frame are obviously fine, since the focusing distance changes very little. The jets are miles away literally, so you're on more or less infinity all the time. Now tracking between 2-10m is a disaster.

edit: and this is not only my 40D. My old 30D did worse, and Canon's demo 50D was not any better. 1D mk3 just about cut it, but I can't quite justify the price tag at the moment.
 
daugirdas said:
Subjects moving across the frame are obviously fine, since the focusing distance changes very little. The jets are miles away literally, so you're on more or less infinity all the time. Now tracking between 2-10m is a disaster.

edit: and this is not only my 40D. My old 30D did worse, and Canon's demo 50D was not any better. 1D mk3 just about cut it, but I can't quite justify the price tag at the moment.
Click to expand...

i use a 40d and i dont have problems in that range, i dont have any problems with the lenses you mention either :shake:

Those that i have tried have all worked very well for me.
 
I don't have problems with my 40D either, with any of my lenses.

TBH I'm usually quite suspicious about claims of front/back focus, especially with longer lenses. That is where user error seems to creep in. But in the OP's examples there doesn't appear to be an obvious user technique problem. It's quite an easy target for the camera to get right a hundred times on the trot. Unless Badger pre-focused some moments before taking the pics, and then the young girl moved.

That's why I think a controlled test would help. If it's the camera, it will show up to a certain extent with all lenses. Or it could be specific to the particular lens being out of calibration. Unlikely with a Canon L lens, but possible. Easy enough to check, as per the link I gave above in post #28.
 
yeah i think this is likely down to user error but as you say a test would prove what was at fault and really needs to be done.
 
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