Hi, I was wondering if anyone had the same problem.
I've been using my canon 60D for 8 months, and in the 8 months I've used different lenses on the body (fix 50mm, efs 18-135mm macro and an EF 75-300mm). All the lenses were focusing perfectly. Lately my 18-135mm lens still focuses perfectly but my 75-300mm lens is back focused.
I tested the lens by putting 3 AA batteries in line about 150mm apart. I put it in line with the lens so that the batteries are all different distances from the camera. Camera was on manual setting, af single point, af on, on a tripod, clip on flash and 2 sec delay to avoid any camera shake.
I let the camera focus on the middle battery and the rear battery is in focus.
I let the camera focus on the front battery and the middle battery is in focus.
If I take off the lens and put it on my D1100 Canon, with all the same settings in manual mode, it's perfect.
How can a lens that worked perfectly all the time on a certain body suddenly have a focus problem? How can I fix this?
Thanks in advance.