Digital BW, The Print

> 
> Paul...you're actually measuring this? How? With what tool?

I scan a featureless film -- like a clear blue sky shot.  (Actually I use a
ground glass over the lens to make frames for comparing grain.  Also, I
shoot a step wedge type target with plain patches for calibrating my
development of film.)  Then in Photoshop the Histogram gives information
regarding the standard deviation within a selected area.  If the film and
scan were perfect, this would be 0 -- all pixels would have the same
density.  However, due to grain and other sources of density differences,
not all pixels are the same value.  The more they deviate from each other,
the higher the measure of "standard deviation."  Most of the density
differences appears to be due to grain.

I think it's a valid and objective way to make comparisons.  Perhaps we have
people more into the math that could comment further and explain the measure
better.

> 
> Are you a statistician? 

No


> Also, have you used Vuescan's "slight grain reduction"?  

No, I don't use Vuescan.  It sounds like it's a software algorithm like the
GEM that Nikon has -- which I find quite useful and better than I seem to be
able to do with Photoshop tools.  

Paul
www.PaulRoark.com