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

["" <derek_c@cix.co.uk>]

Or Nikon could produce scanners with more LEDs in the light source...

On Thursday 28 Mar 2002 3:11 pm, Jeremy Nicholl wrote:
> >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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