Adam, Using the diagonal as the standard one would expect the normal for a 8x10 frame to be about 325mm while the practical standard as you mentioned is only 210mm. That's approx. only 65% of the diagonal.
Do you know where the large difference comes from? Cheers, Gautam On 3/23/06, Adam Maas <[EMAIL PROTECTED]> wrote: > > > > Russell Kerstetter wrote: > > so...... > > > > if you were to take a photo at 50mm with an 8x10, 25mm and digital, > > each time moving farther away to keep the same composition, and then > > enlarge each to the same size print, they will be the same? > > No, because perspective will change. Perspective is directly related to > camera-subject distance. Now if you stayed in the same place, and shot > with lenses of equivalent angle of view, the shots would be identical in > composition (The larger the format, the smoother the tonality as a > general rule) > > > > > also...... > > > > so then on a large format, a 50mm is not really wide, it is just > > larger, because the image coming out of the back of the lens is > > larger, so you can stand closer than with a 35mm, even though it is > > still a "normal" length? > > No, 50mm is an ultra wide-angle on LF (in fact it's a nice wide angle on > MF). Normal on 4x5 is 150mm, on 8x10 it's 210mm. Normal focal length is > typically the diagonal of the sensor/film size (50mm on 35mm film is > only normal because Leica's first 35mm lens was a 50mm, the true normal > for 35mm is 43mm). > > > > > Russell > > > -Adam > >