Quote Originally Posted by Rudeofus View Post
What does this mean: for equal subject framing and equal DOF impression on the final print you keep c/m constant. The larger the film, the larger the circles of confusion may become before a section looks blurry, but at the same time the larger the magnification m becomes. After all is said and done, only the aperture diameter determines your DOF.
Doesn't hold. Here's a 50mm and 100mm comparison, both at 25mm aperture diameter (f:2 and f:4 respectively), both at 0.0101 magnification and same CoC on 35mm film. Same formulae and results as DoFMaster. DoF doesn't match between images.

See: http://theonlinephotographer.typepad...he-sequel.html