Possible Duplicate: How do I convert lens mm to optical zoom times? How can I obtain the "X factor" for a lens? I thought that to get the "X factor" I had to divide the largest focal ...
At what distance from the lens will the image be in focus given a subject distance and focal length? [closed]
I've been trying to figure this one out for more than an hour now and I have no idea how to calculate this... You capture a picture of a tree which is standing 3m away from the camera. The focal ...
What is the actual distance for taking a photograph with a 4.3-180mm Super Zoom camera lens vs. a 55-200mm DSLR lens? [closed]
What will be the true actual distance for both lens in terms of actual meters?