Archived posting to the Leica Users Group, 1999/12/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> The 100 APO macro may not be the best example because, if my recollection > serves, the focal length shortens as you focus closer Yes, you are right about this, but I think that both the stated focal length and the stated angle of view are for the lens focused at infinity. On that same brochure the angle of view for the 35mm lens is given as 64 degrees and that of the 15mm (less than half of the 35mm) lens is given at 110 degrees (not 128 plus degrees). One way to convince yourself that angle of view is not exactly directly proportional to focal length is by drawing little scale diagrams. You will see that this rule is way off for very wide angle lenses, but a good approx. for tele lenses.