Ira Blumberg
Senior Member
After spending 5 months using my 10D and shooting about 700 frames I was concerned about focus accuracy (the frenzy of posts here didn't help either). I have some shots where the intended subject is definitely in focus (mostly at smaller apertures) and many others where it is not. By contrast, I had a much higher ratio of in focus shots with my D60 and the same lenses. I of course did various focus tests and got results showing slight back focus, but it appeared that the focus point was still just barely within the zone of focus.
The thing that pushed me over the edge was that last weekend I took about 70 shots of my son at a park. It was quite sunny and I was shooting at f4.5 and f5.6 at between 1/400 and 1/500. I was using my 24-70L mostly at 70 with a few shots ranging from 35-55. I was between 10 and 30 feet away. I used both AI servo and single shot AF. In some shots my son was quite still, in others he was walking around. For the action shots, I used continuous shooting mode, taking between 3 and 9 frames at a time. When I got home, there was not a single in focus shot. In most shots, my son was sitting / walking on a brick surface, so it was easy to judge the focus point and the bricks behind my son were in very sharp focus (thus this wasn't a matter of camera shake, etc.). This was particularly clear when I applied some aggressive USM in PS. The bricks behind my son got much sharped looking while my son's shirt and the brick in front of him stayed fairly fuzzy. I was using the center focus point only and mostly pointed it at my son's shirt which had nice high contrast stripes that filled the focus point (so the camera should not have gone searching for any other edges on which to focus). Note that I used relatively large apertures precisely because I wanted shallow DOF, which is what I got. I would however have preferred my intended subject to be within that DOF ;-)
Now that folks are reporting good results for focus correction from the Canon service centers, I decided it was time to send in the camera and see if I get improved focus results. I called Canon's tech support line as instructed by the Canon website. The tech asked me a few questions about which lenses I was using (Canon or 3d party, etc.) and whether I had used these lenses with any other bodies. I explained that all my lenses were Canon (50 1.4, 24-70 2.8, 70-200 4) and that they had worked well with my D60. After a few minutes talking he told me to send in just the body. He said turn around time runs 10-15 business days. I hope it won't be that long, but we will see.
I'll post a follow up once I get the camera back.
Ira
The thing that pushed me over the edge was that last weekend I took about 70 shots of my son at a park. It was quite sunny and I was shooting at f4.5 and f5.6 at between 1/400 and 1/500. I was using my 24-70L mostly at 70 with a few shots ranging from 35-55. I was between 10 and 30 feet away. I used both AI servo and single shot AF. In some shots my son was quite still, in others he was walking around. For the action shots, I used continuous shooting mode, taking between 3 and 9 frames at a time. When I got home, there was not a single in focus shot. In most shots, my son was sitting / walking on a brick surface, so it was easy to judge the focus point and the bricks behind my son were in very sharp focus (thus this wasn't a matter of camera shake, etc.). This was particularly clear when I applied some aggressive USM in PS. The bricks behind my son got much sharped looking while my son's shirt and the brick in front of him stayed fairly fuzzy. I was using the center focus point only and mostly pointed it at my son's shirt which had nice high contrast stripes that filled the focus point (so the camera should not have gone searching for any other edges on which to focus). Note that I used relatively large apertures precisely because I wanted shallow DOF, which is what I got. I would however have preferred my intended subject to be within that DOF ;-)
Now that folks are reporting good results for focus correction from the Canon service centers, I decided it was time to send in the camera and see if I get improved focus results. I called Canon's tech support line as instructed by the Canon website. The tech asked me a few questions about which lenses I was using (Canon or 3d party, etc.) and whether I had used these lenses with any other bodies. I explained that all my lenses were Canon (50 1.4, 24-70 2.8, 70-200 4) and that they had worked well with my D60. After a few minutes talking he told me to send in just the body. He said turn around time runs 10-15 business days. I hope it won't be that long, but we will see.
I'll post a follow up once I get the camera back.
Ira