filmscanners: ColorSteps?

[Richard.Starr@valley.net (Richard Starr)]

I don't know if color steps is the right term but it seems to be a display
problem.  In several high resolution scans, I've seen some odd areas of color
that should be continuous appear to step from one tone to another as though
displayed in 256 colors or fewer.   One was a reflective surface with some
specualr highlighs (a polished truck fender) and another was may daughter's
softly lit cheek.  It's a high res 24 bit Photoshop display on the Mac, on a
Sony Trinitron monitor.  I was thinking there was somthing odd about my antique
scanner, but the colors are smooth and continuous in the Epson print.

One example is from an Ektachrome slide, the other from a high speed negative
film.  I thought of the grain aliasing discussed on the list, but I'm not sure
what it looks like.  It appears in all zoom settings of the display, so aliasing
with scan lines wouldn't explain it.

In the display it almost looks like the kind of color reversal you can get when
you bend a curve too far.  It don't show in the print though... weird.

Any ideas?

Rich