On Wed, 26 Feb 2003, Fred wrote: > > Is a 50mm a real 50mm on this new Pentax? > > No. Because the sensor is not a 36mm x 24mm sensor, but is smaller, > the "multiplier effect" applies.
It's a bit more complicated than this. A lens with a focal length of 50mm has the same perspective and DOF regardless of the size of the sensor or film. What seem like differences in focal length are really just differences in cropping, which is a different beast altogether. If you put a 50mm lens on a DSLR and compare it to one on a 35mm film camera, both will give you the same DOF. The apparent focal length will be different, with the DSLR enlarging the subject roughly as much as, say, a 35mm lens with a focal length of 75mm would. But you would get exactly the same effect if you cropped out a part of your 35mm negative and enlarged it, so all the DSLR is really doing is cropping your 50mm shots enough that they look like they were taken with a 75mm lens. Ok. I have a question. I agree that the same focal length lens will produce aprox. the same DOF regardless of format. In the above example if you cropped a 35mm neg to APS size, aprox = to a 75mm lens and you shot the same image at the same spot with a 75mm lens (not cropped) and blew both up to the same size, they would have the same DOF. My question, maybe best answered by D100, D30, D60 owners, is with the APS sized sensor is the DOF the same or greater then shooting with the equivalent 35mm lens? BUTCH Each man had only one genuine vocation - to find the way to himself. Hermann Hess (Damien)
