I keep reading about how a certain lenses can suffer from focus shifting to a certain degree. Being ignorant about several aspects of photography, I tried to come up to speed on the subject. From what I gleaned, it seems this is something that occurs when you focus on a subject wide open, then stop down the lens--without refocusing--which results in the subject being out of focus. Have I got this right? It seems that just refocusing when using a different aperture takes care of the problem. This doesn't seem to be anything too cumbersome for me to do.
So, a last question: Has focus shifting been a problem for anyone here? And, if so, in what situation?
