Re: filmscanners: Was New Nikon performance, now dust

["Dave King" <kingphoto@mindspring.com>]

From: <EdHamrick@aol.com>

> In a message dated 6/10/2001 6:22:35 PM EST,
kingphoto@mindspring.com writes:
>
> > The Agfa is definitely softer,
> >  no argument there, but when I apply unsharp masking to the Agfa
scan
> >  on the order of 75%, 0.8 radius, 0 threshold to the Agfa scan,
which
> >  is my normal amount to sharpen grain with the T-2500, it is about
as
> >  sharp as the unsharpened Nikon scan.
>
> Unsharp masking isn't a reasonable way to compare the scans, since
> this doesn't get to the root of why there's a difference between the
> results from the two scanners.

Perhaps not from a design perspective, but from a users perspective it
seems perfectly reasonable to evaluate scan data in the context of end
results.  After working on both scans, the Agfa, to my eye, has
recorded more real image data.  Rafe brought up the idea of noise, and
perhaps that explains the difference between these scans.  The LS-30
scan appears sharper initially, but after working on both files I
would have to say first impressions are misleading, the "sharpness"
seems to be an artifact.  No matter how I sharpen the LS-30 scan, I
can't get results that match the sharpened T-2500 scan for image
detail and clarity, and tonal smoothness and sharpness of grain.

> A good test would be to turn off "Device|Auto focus" and
> manually vary the focus on the Nikon.  This will give a good
> indication of whether the clarity of the dust spots is related to
> the focus of the scanner.

I don't question the clarity of the dust spots is related to the focus
of the scanner.  The darkening (exaggeration) of the dust appears to
be a function of the infrared channel however, as Rob points out.  I
have no problem with this either, as long as a dust removal algorithm
takes care of it (it does), and I can use the scanner with all
Kodachromes and B&W film and get results as good or better as with a
conventional design (I can't).  I have the feeling that Nikon has
addressed these problems in the new designs, but I would like to know
how effectively before deciding on a next scanner purchase.  Both the
Polaroid 120 and Nikonscan 8000 appear to be excellent with a slight
edge going to the Nikon perhaps.  But is the Polaroid better for B&W
and Kodachrome work?

Dave