Gregory Fraser <Gregory.Fraser@pwgsc.gc.ca> writes: > > -----Original Message----- > > From: Bob Blakely [mailto:Bob@Blakely.com] > > > > For a 4x5 image, 6.4 inches will give 1/3 stop fall off at > > the corners. 3 > > inches will give about 1 stop fall off. > > So the longer the focal length, the less noticeable the falloff. Also, the longer the exposure time. Good. If I use my 4x5 view camera with decent extension, I should be OK. No. At least not the way you express it, Greg. A pinhole doesn't have a focal length - all that matters is the angles, or the ratio of the distance from the pinhole to the film and the diameter of the image circle if you like. "Telephoto" - no falloff; "Wide-angle" - lots of falloff. Brian Chandler ---------------- geo://Sano.Japan.Planet_3 Jigsaw puzzles from Japan at: http://imaginatorium.org/shop/
