Does the grain reduction option in Digital ICE reduce sharpenss of
scans?
YES.
At what scan resolution does grain become visible for Velvia 50 film?
At high resolution, 4000 spi, film grain will be visible. Details will
be also visible and the image sharp and clear.
At low resolution, 1000 spi, film grain will not be as visible, Details
will suffer and the image soft.
Turning on "Grain Reduction" or "Grain Dissolver" WILL reduce sharpness
and image detail.
Film has grain. When you shoot on 35mm Film you must accept grain. If
you don't accept grain, then go digital, but there, you must accept
other artifacts.
If you want a "perfect" photo, just like the national ads, then forget
35mm and medium format, and go with a 4x5 / Large Format.
Personally, I will never sacrifice resolution for grain reduction.
People generally can look 'past the grain'. Open any magazine and look
at a quality ad: you'll see the grain. But, again, you have to be
looking for the grain.... Grainless Sports Photos, such as the ones
published on Sports Illustarted magazine (not the ads), you can clearly
see that the athletes are nowadays represented like "soft paintings".
This is an artifact of 'processing'. They are basically trying to
dossolve the noise/grain that digicams induce at high ISO speeds.
Grain is Acceptable and unless you view at 100% real size, you don't
notice it. If you do, then you'll also notice CCD noise, among others.
But I don't know many people looking at photos with a 20x loupe...
For examples, look at the following link and see yourself the kind of
destruction that grain reduction can do to your photos:
http://www.photozone.de/2Equipment/reviews/elitecoolscan.htm