I've lately been asked the question, "How far does it zoom? 1/4 mile? 1/2 mile?" when using my 70-200 f/2.8L IS. How do you respond to a question like that!? I've seen on here people discussing weird questions they get asked, but haven't heard of this one before. Just, how do you rate a zoom in terms of mileage? I simply tell them... "let me find this shot of the April 12 moon crater [sift through photos]...oh, must be on a different card..."