[filmscanners] Re: Depth of Focus (was Nikon LS-40 vs PolaroidSS4000)

["Jeremy Nicholl" <mail@jeremynicholl.com>]

>Depth of Focus. Could we get this topic back?
>Is it a light source issue, lens/aperture?
>Or is it a Depth of Field problem caused by the Film carrier's
>inability to keep film flat?
>DaleH
>


It's a combination of all of the above. The 4000ED light source
apparently requires a wide aperture = limited DOF. Combine that with
the film holder's inability to keep the film flat enough and the
result is scans which lack edge to edge sharpness. The problem
doesn't exist on the Polaroid 4000 because its light source is
sufficient for a smaller aperture = greater DOF, meaning that even
though the Polaroid film holder is far from impressive scans are
sharp unless the film is noticeably warped.

I suppose the solution would be for Nikon to produce a glass film
carrier similar to that which they make for the 8000ED. However they
may not wish to do so since that would in itself be an admission of
the problem.

Jeremy Nicholl
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