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...

Loris,

A search on "grain aliasing Epson 2450" gives a lot of hits so
this isn't new.

You could be in good company, Norman Koren doesn't think it is
grain aliasing either with the 2450 (and so the 3200):

http://www.normankoren.com/Tutorials/MTF8.html

middle op the page.

Norman writes:
"I must add that the 2450's large apparent grain is not the
result of grain aliasing. It is the result of the 2450's low
sharpness, which softens both the image and grain, and hence
emphasizes low spatial frequencies"

The film used was FP4 B&W, 35 mm.

I'm in the my last thrench now :-) ... it isn't noise!

Regards, Ernst