Back focus issue - camera, lens, or photographer problem?

[reader0428]

I have had intermittent problems with photos where the lens (or camera, I'm not sure which) appears to have "back focused", where the spot I chose as the focal point is not sharp, but the stuff 2-3 inches behind the place where I put the focus point is sharp. Case in point (disclaimer: pics have not been edited much so these are not showcase worthy!!!):





Settings: Canon 5D, Canon USM 50/1.4 lens, f2.2, 1/1000, ISO 400

I put the focus point on the baby's right eye, but it's the left eye and the right ear that's in focus. If I had focused on the left eye, this would be a DOF issue. But I focused on the right eye, and it is not sharp. I have this issue now and then , but on this session, fully 75% of the images came out this way. When the baby is facing straight ahead and I focused on the eye, his face is soft but ears are razor sharp. I am beyond frustrated. This is a lens I've had for a few months (50mm/1.4) and have not had an overwhelming number of shots turn out this way before with this lens (or any lens), although it does happen on occasion. I just had the camera professionally cleaned and serviced, and this is the first session I've done since getting the camera back. Could this have anything to do with it? Or am I unknowingly doing something wrong? For the most part these were not focus-recompose, I was using the center focus point. Just trying to figure out if this is a camera issue or a lens issue, since it does seem to happen some of the time with all my lenses but never to this degree. Any words of wisdom? (I've been told that Canon has focusing issues, which I can attribute my now-and-then problems to, but this many bad ones out of one session seems to point to something else.)

[ChrisTX]

I returned a lens that did that. I did the below setup with the left one just a little bit further back than the right one. Numerous shots duplicated the same thing, with some worse than others. You can see the problem I had. When I returned the lens, I wanted them to fix it, but they told me nothing was wrong with it. It's the only lens I've ever had this problem with. Try different lenses and see what you get.

[venchka]

A tripod & a tape measure will confirm exactly where your lens is focusing. There are diagrams and photos of the setup on the internet. A fixed camera and a fixed point of focus are essential for accurate results.
Good luck.

[Photogdude]

you absolutely need to use a ruler and a tripod and the cameras proprietary software to really see whats going on.

[mrsrice22]

Can someone go more into details on the last two comments as far as how you check/test using the above mentioned method?

[Photogdude]

put your camera on a tripod, put a ruler on a table. raise your tripod so you ned to tilt down the camera down a bit to se the rule in the frame. put a focus point somewhere on the ruler. Shot a few shots wide open, use auto focus and also check it with manulay focus. once your done look at the pics, preferably with the camera software so you can se the actual focus point.

I took this and looked at it in Nikonview so i could se where the focus point was.

Attachment 149786

[venchka]

Focus on one of the major whole foot points. Slide the ruler back and forth to line up with where the camera is focusing. Write down where you focus. Place a pencil point first next to where you think you focused. Start wide open. Then close down 2 stops. Some lenses have focus shifts as you close the aperture.
I'll get flamed for this, but...
You could try to do your own searching. GOOGLE found all of this for the words focus check:

Google

[reader0428]

will try the ruler/tape measure test tomorrow.

[mrsrice22]

Thanks Marshall!

Wayne - I don't know why you'd get flamed for suggesting someone go do their own search on Google... Though I also don't see why if someone on the forums asks a question why they should be told to go find the answer/help somewhere else, I thought that was one of the many perks of joining an online forum. /sarcasm ;)

I have used those focusing sheets before about a year ago when I noticed my images weren't focusing on the AF point I selected. It just didn't click last night what you folks were talking about.