[filmscanners] Re: Sharpening after scanning (SS4000): question forArt

["Arthur Entlich" <artistic@telus.net>]

Hi Stan,

I may have mis-spoken or at minimum, been misunderstood.

You are correct that sharpening should occur prior to printing.  Saving
the image sharpened is not necessary, and may, in fact, be detrimental
since sharpening adjustments vary depending upon final output size and
other factors.  They may even depend upon the printer type and driver
software.

I cannot give you absolutes in terms settings in using unsharp masking,
because it depends upon many factors.  Some include the type of image or
subject matter and contract, color intensity, etc, the size the imagine
is going to be reproduced to, and the scanning resolution used, the type
of source material (the film base used) and indeed the type of scanner
and if things like dICE is used or not.

By trial and error, I have a "sense" of the settings depending on these
factors, and how the image looks on the screen at differing magnifications.

However, my principal point is this:

All CCD based scanners tend to introduce softening which can in part be
recaptured via unsharp masking.  This softness is not a defect in focus
or optics or the CCD, but is intentionally introduced to reduce the
amount of noise and artifacting (Nyquist errors) that develop in the
analogue to digital transfer which occurs in the scanning process.

No image should be compared until optimum unsharp masking is
accomplished because some manufacturers will uses some USM to make their
scanners appear to have higher sharpness and resolution when actually
introducing this higher focal accuracy may add unnecessary and even
undesirable artifacts which cannot later be removed.

Keeping the image unsharpened for storage does indeed allow you to
adjust those measurements to the output method and size.

Art


Stan Schwartz wrote:

> A while back, Art mentioned sharpening a scanned transparency image
> before saving it--to restore some of the loss of sharpness inherent in
> the SS4000 scan. I am curious to know what degree of sharpening you use,
> in Photoshop terms re: %,radius and threshold, for this task.
>
> I've usually reserved sharpening as the last step before printing,
> leaving my archived image unsharpened.
>
> Stan Schwartz
>
>
>
>

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