I have a Nikon D3100, and I am borrowing an old Nikkor 50mm SLR lens (http://www.destoutz.ch/lens_50mm_f1.8_1828564.html). I've had a lot of trouble with that lens, in that pictures that appear ...
I have a Canon 550D with 70-200 f4 and 50mm prime lenses. Although the camera has built-in 9 focal points, I sometimes face a strange problem. Here's a sample photo: In reference to the above pic, ...