[filmscanners] Re: film scanner light source

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

Hi Barry,

The answer is "it is, and it does".


It is like the condenser versus diffusion debate (almost exactly), and
it does make a difference.

Overall cold cathode tubes lighting provides a diffuse light source.
The exception appears to be Minolta scanners, which seem to need an
auxiliary defuser.  And in fact, that scanner series may be the perfect
example of the problem.

People often complain with ether Minolta scanners that the dust and
scratches are very obvious, and grain seems exaggerated.  A private
company now makes a diffuser for one Minolta model and claims to made
the scanner from being one of the worst to the best. (this is their
Minolta Pro medium format, but the principle is the same).

By scattering the light a bit, all the junk on the non-emulsion side,
the dust, dirt, fingerprints, scratches, etc. as well as defects within
the film base.  By scattering the lightsource, they get generalized
lighting that tends to diminish the visibility of these defects while
having little to none effect on the image content.

The Nikon uses LED lighting elements which are collimated light sources.
  It very definitely brings out the nasties on film, but dICE can help
to remove it (but not on true black and white film - IR can't go through
silver images).

The other problem some Nikon's have is likely due to the lower light
intensity of the LED light source.  As a result, Nikon had to open the
lens aperture within the scanner wider, and therefore depth of field can
be compromised, when scanning films that are not nearly perfectly flat.

  Art


barry wrote:

>  I ask this group does it really matter what the scanner light source is.
> Some suggested to me that there were two kinds and that the Nikon IV would
> be a bad choice. I suspect this would be like the old diffusion versus
> condenser enlarger debate but thought I would ask anyway just in case
> someone has practical experience.
>
> Barry T
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