Hi Harvey--
Well I could easily be wrong. Or I & they might be looking at
different things.
I'll tell you what I was thinking specifically of when I wrote my
comment: I've been scanning various reflective and transmissive
greyscale targets on a new flatbed scanner and comparing the results.
One of the things I've been doing is looking at the standard
deviation of the pixel values within each grey step. I figure that,
particularly at the dense end, increasing standard deviation
indicates an increasing level of scanner noise. Well I was comparing
tranmissive scans from two IT8 targets, one 35mm and the other 4x5,
and the standard deviations on the 35mm target were huge in the dense
end but similar in the low-density end. I couldn't understand why
two targets of equal density on the same scanner could be so
different; until I inspected both scans closely and realized that the
25mm target was hugely grainy, especially in the dense end of the
greyscale. So what at first I thought was scanner noise turned out
to be film grain.
Now does this sound at all like what they've been discussing on the
Colorsync list? Am I looking at this the wrong way?
Regards,
--Bill
At 1:10 AM -0400 23-10-01, SKID Photography wrote:
>Bill Fernandez wrote:
>
> > I've became aware of this when I was doing similar analysis recently;
>> that much of the apparent "scanner noise" was in fact film grain. So
> > now that I'm aware of this I factor it into my testing.
>>
> > --Bill
> >
>
>Bill,
>What you write, runs contrary to all of the recent (6 months)
>threads on the colorsync list regarding grain
>and noise. Not that you are wrong, it's just what I've read and
>experienced with magazines scanning our work
>for reproduction.
>
>Harvey Ferdschneider
>partner, SKID Photography, NYC
--
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Bill Fernandez * User Interface Architect * Bill Fernandez Design
(505) 346-3080 * bill_sub@billfernandez.com *
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