PARDON MY "UPPERCASING" JOHN, BUT YOU ARE SENDING "HTML" MESSAGES, SO I AM WRITTING IN UPPERCASE TO DIFFERENTIATE THE ANSWER FROM YOUR POSTING.
----- Original Message ----- From: john yeo A few days ago I made a pinhole body cap for my canon AE-1. I made the pinhole as small as I could, it ended up .0065 +/- .0005" f/270. Would using one of the formulas to determine the optimal size work better for such a small focal length? Or does that only apply to longer focal lengths FORMULAS APPLY TO ANY FOCAL LENGTH. IMO, 0.0065 IS OPTIMUM FOR A MUCH SMALLER FOCAL LENGTH SOMETHING LIKE 20mm. THE FORMULA I USE (D = 0.0073 SQRT(F) inches) GIVES 0.0097" AS THE DIAMETER TO USE FOR A 45mm FOCAL LENGTH (I think this is what you have), SO I'D USE A 0.009" PINHOLE FOR AN f/196 (or f/180+1/4) AND I"D CONSIDER IT IS f/180+1/2 OR EVEN f/256 (pinhole are more likely to be underexposed than over). I walked to the post office and took the camera with me. Just took pictures of whatever. I even shot some cars moving at 45mph!!! All exposures except for the first few were hand held. YOU REALLY HAVE STEADY HANDS, I HAVE TO HANDHOLD ANYTHING SLOWER THAN 1/125 SECS!! here's a scan of the contact sheet: low res 64kb http://holgamods.blinkk.net/images/ph35cs-lowres.jpg high(er) res 192kb http://holgamods.blinkk.net/images/ph35cs-hires.jpg I"D BE NICE IF YOU CAN BLOW UP (8x10 perhaps) ONE OF THE FRAMES, SCAN IT AND LET US SEE WHAT IT LOOKS LIKE, I'D CERTAINLY BE INTERESTED. Guillermo
