Hi: I _think_ this is what happens - knowledgeable people feel free to correct me.
There are two things that limit the pinhole resolution: I believe a pinhole image's - the negative - limit of resolution is the size of the pinhole - The finest detail the image can create is the same as the diameter of the pinhole. If this were the only factor then one could make an infinitely small pinhole and create images with "infinite" detail. Unfortunately light diffracts around the edges of the pinhole. The smaller the pinhole the more diffraction. At a certain point making the pinhole smaller makes the image less sharp. There are formulas for determining the ideal pinhole. It is still possible to get very sharp pinhole images. The ideal method is to not enlarge the negative but contact print it. You are more or less correct, as you enlarge your image from a pinhole negative on 35 mm film you will be making the limited resolution of the image more apparent. If you want a really sharp 8x10 pinhole images the best way to produce this is with a pinhole camera that takes 8x10 inch negatives. This can be done without a full-fledged darkroom. See my website for examples and details: http://cyano.usask.ca/cgi-bin/photo/index.cgi If you want color images this becomes a little more challenging - you could use large format color film or ilfochrome. If this is what you really want to do I would recommend getting used doing this in black&white first. On Thu, 16 Aug 2001 mvdtempor...@aol.com wrote: > Hello: > > Excuse me if I already asked this - if I did, I forgot the replies already > (but I don't think I did). > > > BUT, people are telling me I will probably be disappointed by anything > larger than 5 x 7 or so from my 35 mm pinhole negatives because they say > pinhole images are "not very sharp". > > Is this just anecdotal advice from people who simply poked a hole without > consideration of all the things that play a role....(that wasn't supposed to > rhyme, it was an accident)? (Optimal hole diameter/focal length, thickness > and roundness of pinhole material and resultant hole, etc.) > > Thanks > > Murray > > --------------------------------------------------------- Gordon J. Holtslander Dept. of Biology hol...@duke.usask.ca 112 Science Place http://duke.usask.ca/~holtsg University of Saskatchewan Tel (306) 966-4433 Saskatoon, Saskatchewan Fax (306) 966-4461 Canada S7N 5E2 ---------------------------------------------------------
