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Title: pinhole camera Post by: KeithB on October 12, 2009, 08:15:30 PM In one of Bob's articles on Depth of field he states:
"This covers the case of a pinhole camera. Such a camera has a very, very large depth of field (almost, but not quite infinite). However none of the image is sharp. The depth of field is large because all the image is equally blurred! " Is the lack of sharpness in the pinhole image due to diffraction effects? Title: Re: pinhole camera Post by: whizkid on October 13, 2009, 09:30:10 AM Diffraction is certainly a factor. Here's a brief about the theory.
http://www.pinholephotography.com.au/Theory/theory.html Title: Re: pinhole camera Post by: Bob Atkins on October 14, 2009, 07:25:31 PM Diffraction is the limiting factor. You can make diffraction less important by using a larger pinhole - but of course that blurs the image too (since there's no lens in there!).
There's actually an optimal pinhole aperture which is something like: diameter = 2 * square-root (f * lambda) where f is the distance from the pinhole to the film/sensor and lambda is the wavelength of light (you can use 0.00055mm for visible light) Title: Re: pinhole camera Post by: KeithB on October 15, 2009, 01:27:29 PM Thanks, Bob and Whizkid!
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