Lens Issues with canon 70-200 f/4 IS

hey guys my canon 70-200 has issues i believe with back or front focusing. when i use the lens i notice its really soft around edges and sometimes one part of an image is in focus and the rest of the image isnt. it is really noticable at wide appertures f/4 etc. where the images arent even usuable. just want to know if anyone has had issues like this and whats the best course of action to get this fixed. ive attached an image to show what the images come out like.

f/4 as you can see image looks blurry

Something is amiss for sure. You might try taking some test shots with IS turned off. This lens is very sharp, even when used at f4. Or maybe try another camera body if you have access to one as a way to eliminate suspects.

I am a relative beginner, & I have this lens on a 7D, & have to say, this is one of the worst images I have seen with this lens. I was thinking, maybe a focus issue, but the whole of the frame is fuzzy. How long have you had the lens, is this typical of the result you are getting? 1/1600 should all but eliminate camera shake, but as one poster has suggested, try it on a tripod, man focus, IS turned OFF, mirror lock-up & timer delay.

scottyf123 wrote:

hey guys my canon 70-200 has issues i believe with back or front focusing. when i use the lens i notice its really soft around edges and sometimes one part of an image is in focus and the rest of the image isnt. it is really noticable at wide appertures f/4 etc. where the images arent even usuable. just want to know if anyone has had issues like this and whats the best course of action to get this fixed. ive attached an image to show what the images come out like.

I agree with another responder that there is both subject and camera movement in your example.  Do you have another example with a static subject?

That said, my 70-200/4L IS did develop a problem.  After several years of flawless use, the lens unexplainedly could not produce a sharp image.  I can best describe the results as a "lens baby" effect (much worse than your example).  I sent it in to Canon for an out-of-warranty repair - for $200 they replaced some parts and fixed it.

There is nothing in focus in that pic, left right up or down.  Doesn't look to me to be misalignment, nor front/back focus.  Agree with Peter Too, it looks like it's at minimum focus distance, maybe due to the obstruction at lower left.

The "nervous" bokeh and misty-ness look like the result of a protective filter (get rid of it) and/or condensation on the filter or lens.

IMHO, YMMV

scottyf123 wrote:

hey guys my canon 70-200 has issues i believe with back or front focusing. when i use the lens i notice its really soft around edges and sometimes one part of an image is in focus and the rest of the image isnt. it is really noticable at wide appertures f/4 etc. where the images arent even usuable. just want to know if anyone has had issues like this and whats the best course of action to get this fixed. ive attached an image to show what the images come out like.

f/4 as you can see image looks blurry

Do a few controlled tests of static subjects, with different aperture/shutter speed combinations. Preferably on a stable tripod. A flat object (paper, brick wall) will show whether the focus is off or not. Also try taking a picture with details close and far away to see if there is any place in the frame that is sharp. Use the Canon software to see which autofocus point was used. There are lots of things you can do to evaluate the lens before deciding to send it to Canon.

The 70-200 f/4 IS has a very good reputation but it may be defective.