If you're already shooting at 1/2 to 3/4 second in sunlight what's
another 1/3 stop amongst friends? :-)
Chuck Norcutt
Moose wrote:
> Chuck Norcutt wrote:
>> Complete with Lord Rayleigh's formula for optimal pinhole size.
>> <http://en.wikipedia.org/wiki/Pinhole_camera>
>>
>
> I'm aware of the formula. However, Zero Image doesn't follow it:
>
> Pinhole diameter
> Model Format FL mm Camera Rayleigh
> 135 35 mm 25 0.18 0.22
> 2000 6x6 25 0.18 0.22
> 69 6x4.5 - 6x9 40 0.18 0.28
> 612 6x4.5 - 6x12 40 0.25 0.28
>
> Given Zero Image's relative success and longevity, their endless
> statements on their site about fanatical testing and QA, and Bill's
> statement that they are particularly sharp, I assume their pinhole sizes
> are based on empirical testing with the actual pinhole material
> thickness, material and pinhole sizes.
>
> According to "Pinhole Photography", by Eric Renner, it appears that
> Rayleigh's formula was empirically derived from experimentation.
> Although E. Lommel had done the first calculation of diffraction through
> a round aperture in a paper in 1885, it was not well known when Rayleigh
> came up with his almost identical formula in 1891. There are also other
> formulas in use. <http://photo.net/pinhole/pinhole>
>
> So, I wasn't looking for theory, but info on practical results. BTW, the
> downside of Zero's smaller apertures is slower f-stops and longer exposures.
>
> Moose
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