Re: Unsharp mask was Re: filmscanners: Getting started question

[Arthur Entlich <artistic@ampsc.com>]

Yes, the issue is not just the percentage.  You will note, if you play
with USM, that all three settings are involved in the degree of USM
that's visible.

If you decrease the radius, let's say to under 1, you can boost the
percent to several hundred before you see any obvious artifacts from the
process.  Also, if you boost the threshold, so that wider expanses of
area, like sky, or say the large areas of a face are not sharpened, you
might be able to use more USM to bring out details (like a model's eyes,
for instance) without their skin turning to orange peel.

Also, you should know that USM usually looks more intense on your screen
(for images to be printed) than it does during the actual printing
process, due to the nature of the dithering process. So it can look
a bit exaggerated on the image on the screen (at 100% view) and still
look fine on the print.  You'll need to experiment for finding how far
you can push this.

Lastly,  I have found the amount of USM you can get away with depends
upon the scanner and the film in use.  If the scanner or film tends to 
exaggerate grain, defects, or noise, you can't go to far with USM,
because 
these are indeed the types of things that USM will "enhance".  If your 
scanner has low noise, doesn't grain aliase, or exaggerate dust
scratches 
and the like, you can pump the USM up a fair amount without it looking 
unnatural.

Art

Rob Geraghty wrote:
> 
> "Frank Nichols" <frank@theNichols.net> wrote:
> > something I CAN do to it - they are coming out almost perfect. The
> scariest
> > part so far has been trying to figure out the USM to use. These are Provia
> > 100F slides scanned at 2700 DPI on my Scanwit and they look a bit "soft".
> > However, where I normally start getting nervous if I use over 150% at 1.2
> > radius with threshold of 4 on negatives (Kodak Super 100) here I am up
> into
> > 250% or more before I see the effect I want - and I seem to have to be
> more
> > careful to avoid pixelization at those levels.
> 
> Gad, unsharp mask over 100%?  I've been using a radius of 2.0 and only 60%.
> Is there something I'm seriously missing about USM?
> 
> Rob