RE: filmscanners: best film scanner for b&w negs

[Mike Duncan <mgduncan@esper.com>]

>> You might be interested in the measurements I made on my Nikon IV ED with
>> the Stouffer B&W target.  Different curves are obtained with different
>> media settings in NikonScan and Vuescan.  0 is the lowest density step on
>> the Stouffer which I estimate to be about 0.15 OD. The LS4000 should have
>> better results.
>>
>
>Very nice.  I particularly like your converting from 0-255 to scanner
>density.  I plan to do the same type of plot with my scanners, but I would
>like to add
>       a) plot each color and
>       b) error bars representing the noise.
>I was going to calculate the noise in Photoshop by drawing a box slightly
>smaller than each patch and reading off the standard deviation from the
>histogram window.  The rest was going to be done in Excel.  Biggest problem
>is the time it will take to manually read off all the values.  This would
>seem to be an ideal way to compare different scanners and software packages
>- at least as far as their dynamic range and maximum useable optical
>density.  If I have time this weekend...

I have standard deviation data.  The problem is it's hard to tell how much
of the standard deviation is film grain and how much is scanner noise.
Most of the IV ED deviation is film grain.  The Stouffer target has large
grain.

Mike Duncan