----- Original Message ----- From: "Ed Kirkpatrick" <ed.kirkpatr...@verizon.net> > > I am interested in sieves. Are they one size fits all or specific to > the focal length?
Ed, Sieves do focus light using diffraction, as supposed to glass lenses which use refraction, therefore, Sieves are manufactured for specific focal length. > What is a good source for them? You can get pre-made Sieves of 50mm, 75mm and 90mm focal length from Pinhole Visions site, or you can also get the same pre-made Sieves mentioned above plus custom made of any other focal length, directly from the developer of the Pinhole Sieve technique at http://members.rogers.com/penate/customZP/customZP.html . Prices are the same and you can pay using credit card and PAYPAL from either site. The developer of the P.Sieves manufacture the sieves sold at PV site and the ones sold by himself, obviously. > What are they made of? Short answer, they are made on a piece of high contrast lith film. For a long answer go here: http://members.rogers.com/penate/sieve/photonsieve.html Guillermo
