John, I've been working (slowly) on my own camera as well. I've found the following page pretty helpful in creating the design I am developing:
http://www.mrp at ???????/ There are a number of calculators for focal length, exposure, and pinhole diameter. Hope that helps a little, Doug ----- Original Message ----- From: "John Aengus Burke" <john_aengu...@hotmail.com> To: <Pinhole-Discussion@p at ???????> Sent: Sunday, October 12, 2003 7:48 PM Subject: [pinhole-discussion] small apertures > Hello > I have recently constructed a pinhole camera from hardwood. Apart from > certain teething problems I am most concerned about the fstop of my camera. > In order to be able to guarnetee getting a sharp image I got a jeweller > friend of mine to drill a beautiful hole in a piece of thin metal for me and > the camera has an adjustable bellows to allow me get the optimium focal > length by trial and error. I haven't taken it out for a trail run yet > because I haven't had access to a darkroom for a while. However that aside I > am worried about the size of the pinhole. My focal length is roughly 12.5cm > and the pinhole is between approx.0.5 - 0.8mm from what I can tell. I am > worried about diffraction and also exposure time. Now given I will be > exposing onto 120 film I don't expect to be waiting all day but still I > would be grateful if anybody has any suggestions. Do you think the pinhole > is too small? And given its size, as it seem sto me the projected image > would be extremely small on the focal plain, do you agree? > John Burke, Ireland. > > _________________________________________________________________ > MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. > http://join.msn.com/?page=features/virus > > > _______________________________________________ > Post to the list as PLAIN TEXT only - no HTML > Pinhole-Discussion mailing list > Pinhole-Discussion@p at ??????? > unsubscribe or change your account at > http://www.???????/discussion/ > >
