Archived posting to the Leica Users Group, 2000/05/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Agreed, but if you are doing it yourself with aluminum foil and a pin, without a machine cutting a precision pinhole, then "as small as you can make it," is probably the best approximation of optimum size, isn't it? Tom - ----- Original Message ----- From: "Henning J. Wulff" <henningw@archiphoto.com> To: <leica-users@mejac.palo-alto.ca.us> Sent: Monday, May 22, 2000 4:05 PM Subject: Re: [Leica] pinholes > At 11:48 AM -0400 5/22/00, Tom Schofield wrote: > >1) As small as you can make it. > > No, no, no! The right size hole is one where the benefits of making it > smaller, so that less spreading of the image occurs, is just balanced by > the benefits of making it larger to reduce diffraction effects. This > balance is extremely important. As diffraction effects are a function of > the perimeter length and the area of the opening, it is also very important > to have a clean, circular opening through as thin a material as possible. > Gold is best, as it can be made very thin while still opaque, but brass is > very good and is the usual choice. > > * Henning J. Wulff > /|\ Wulff Photography & Design > /###\ mailto:henningw@archiphoto.com > |[ ]| http://www.archiphoto.com >