Digital BW, The Print

I know that article; that's a very interesting one indeed.

A quotation:
"...What appears to happen, is that once the grain clumps reach a
critical size (approaching pixel size) aliasing is unavoidable, and this
effectively amplifies the grain, making it much more visually obvious
and objectionable..."

If so, let's make some calculations:
For a 3200dpi scanner (while Epson NOT being one - "pratically" I mean)
pixel size is = 1 / 3200 / 2.54 / 10 ~= 0.008mm (8 microns). It has been
said that human eye may resolve detail as much as 8 line pairs per
millimetre. 8 line pairs are formed by 16 lines. 1mm / 16 lines =
0.0625mm (62.5 microns) and 62.5 / 8 ~= 7.8x.

If the 3200 is able to show grain - or grain aliasing - then according
to the above calculations the grain clump size should be greater or
equal to 8 microns. If this is the case then any enlargement for 35mm
film beyond 7.8x ( 8 x 11 " paper) should clearly show individual grain
clumps - which is not the case. Confusing indeed...

Best regards,
Loris.

> -----Original Message-----
> From: Ernst Dinkla [mailto:E.Dinkla@...] 
> Sent: Friday, March 14, 2003 11:34 AM
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: Re: [Digital BW] RE: Is this noise or what? (was: 
> Epson3200 - Test results)

...

> > > another category. You could be right as I'm too often thinking of 
> > > the Nikon 8000's results that I have of those films. 
> Still I can't 
> > > put the term "noise" on it. This is from the light parts of the 
> > > film. What are the results in the shadows when scanning a 
> slide ? If 
> > > it is a noisy scanner then
> >
> > Noisy... and then fuzzy - due to multipass scanning in order to
> suppress
> > noise ;)
> 
Loris,

Or just plain grain aliasing like explained at

http://www.photoscientia.co.uk/Grain.htm

With just a hint of grain, clouds or whatever pattern in the scanned
data it can be made into something nasty. Could be the multiple CCD
arrangement of the Epson that plays a role in that.

Ernst