[filmscanners] Re: Depth of Focus (was Nikon LS-40 vs Polaroid SS4000)

["Arthur Entlich" <artistic-1@shaw.ca>]

Depth of Field (Focus) on the Nikon product...

Well, in a way, you could say it's the carrier, or the slide frame at
fault.  If the film were perfectly flat, the focus would be fine
throughout.  Problem is, hardly any film is.  On other film scanners
this is dealt with via an optical path which creates sufficient depth of
field to keep the typical amount of variation in a film frame within its
focal range.  On the Nikons, the DOF is sufficiently limited to create a
problem.

Why?  I have my suspicions, but I don't know for sure.  Could be the
light source isn't bright enough causing a need to keep the lens
aperture larger, could be the light source isn't bright enough,
requiring a shorter optical path, which can also limit DOF.  Could just
be a design element to the scanner we don't know about, only Nikon knows
and they aren't saying ;-)

Art


DaleH 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
>


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