4x5 Pinhole vs. 8x10 Pinhole

[Jim Becia]

I have several questions concerning pinhole cameras. I had an 8x10 and got a few interesting images using some expired 8x10 Ektachrome. My only problem with the camera was that its effective focal length was somewhere around a 95mm which was just too wide for my eyes so it has been sold. I have one of the Wanderlust cameras coming my way, and while I did find a very nice 90mm Schneider for it, I was thinking of using it as a pinhole to try a few ideas that I have in mind. My questions: if I want to print an image up to 32x40, will there be a noticeable difference? Would a print from an 8x10 pinhole be "sharper?" Does that make sense. Another question, since we are dealing with a pinhole, with a well exposed slide, am I to assume that a scan from my Epson 750 would be adequate, at least in terms of resolution. I have a fair amount of expired 8x10 and I'm trying to decide if the new Ilford 8x10 is a way I want to go, or if I should just stick with the Wanderlust when it arrives. I may end up shooting some b&w down the road also, but would be curious to know from those that have used both 4x5 and 8x10 pinholes what the practical differences would be in a final print of an image in the 32x40 size. Thanks.

[Jim Jones]

For equal size enlargements from 4x5 and 8x10 pinhole cameras with equal angle coverage and ideally sized pinholes, the 8x10 will have more detail than the 4x5. Resolution on film is directly proportional to an optimum pinhole size. While optimum pinhole size is larger in larger cameras, the increase is only 1.4x the film size when angular coverage remains constant. Contrary to what a few "experts" have stated, an optimum size pinhole can resolve line pairs with a spacing finer than the pinhole diameter on the optical axis, if not in the corners. An Epson 750 at 2400ppi resolves much finer detail than any 4x5 pinhole camera.