----- Original Message ----- From: "Uptown Gallery" <mur...@uptowngallery.org>
> If one set up a 4x5 bellows camera for pinhole with an appropriate pinhole > for double extension (say 300 mm), placed the bellows at 300 mm but used a 4 > x 5 filmholder, would that place the worst of the edge falloff outside the > 4x5 image? It seems to me that this would work, at least to reduce the > effect somewhat. Although fall off, technically speaking, starts right as soon as we depart from the very center of the filmplane, it'll not be noticeable until a distance around half the diagonal of the image format. In other words, as long as your focal length is equal or greater than what it is considered the "normal" focal length for the format, the fall off can be disregarded. As a matter of fact, if you are enlarging a negative made with a 150mm focal length pinhole, and you use a 150mm enlarging lens to do it, the fall off in the negative will be corrected by the fall off of the enlarging lens. This is one of those cases in which 2 wrongs make a right!! Guillermo
