[filmscanners] RE: another Sharpening question

["Paul D. DeRocco" <pderocco@ix.netcom.com>]

> From: Ed Verkaik
>
> Just imagine a typical sky -- either one with cloud elements and
> blue sections,
> or cloudy with varyiong degree of light and dark areas (stormy
> sky).  Surely
> there are generalizations we could apply to such subjects?  I
> always assumed
> that since clouds have no natural "edges" that sharpening is not
> relevant and
> maybe even detrimental.  Unfortunately, my limited vision does
> not detect fine
> changes in contrast or sharpness.  In a perfect world, I would
> try to come up
> with a single (mild) degree of sharpening to apply to all images,
> either through
> an action or with dedicated software.  I'm hoping the experience
> of others can
> lead me to a solution.

Actually, I should make one further point, which is that Unsharp Mask can
also be used as a localized contrast enhancement, by setting its diameter to
something near its maximum value, rather than to the usual very small value.
This is particularly useful when you want to enhance local contrast (perhaps
even in clouds), but you have too much overall dynamic range to use a more
conventional Levels or Curves approach. If all you have is clouds, though,
Levels or Curves should work fine.

But that use of Unsharp Mask isn't really sharpening.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@ix.netcom.com

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