Re: filmscanners: Film grain vs 2700 & Stains & Grains..

["Mark T." <markthomasz@ozemail.com.au>]

>Tony Sleep wrote:
>..No, IME you are unlikely to see genuine grain off ISO200 Fuji using
> >2700ppi. You are likely to get some aliasing which looks like grain. A way
> >to check this would be to have a reasonably large C41 print made (say
> >12x8"). I'll bet.

There's a cheaper way for those who don't home process, but have a decent 
slide projector.  Just stick your negative into a slide mount and project 
it.  I found this *very* enlightening as I grapple with grain-aliasing (or 
whatever it really is) on my Acer.

Tony's description of scattered dye clouds seems to perfectly describe the 
awful stuff that really does exist in the 'shadows' of most of my 
negatives, even Reala (although it's by far the best - thank you 
Fuji!).  Naturally it is worse on fast films - but it also seems to vary 
within film stock eg some Kodak 100-6's seem particularly bad, which 
suggests the importance of good processing. Although I s'pose it could be 
poor storage/film batch variation, or maybe just not many underexposed 
negatives in that roll.. :)

And to Frank N - visited your Stains & Grains site, and read your comment 
'I would expect there is no emulsion "grain" to create an aliasing effect' 
(in clear areas of negs).  I thought exactly that 6 months ago, and to test 
it, I did a second scan of a woefully underexposed neg *upside down* and 
compared the 2 noise patterns.  To my surprise, it was a very close 
match.  So I projected the negative on my wall and sure enough, I could see 
a close correlation with the 'stuff' in the negative to what the scanner 
'saw' (and unfortunately emphasised in glorious/spurious colour).

Lastly, for the record, my Acer gives very even illumination - I can just 
detect a slight fall off to the long edges when I do ridiculous things to 
the contrast, but it has absolutely no detectable effect on my 
images.  Like you said, if it isn't causing a problem on real images, I 
wouldn't fret too much :)  I suspect scanning blank frames and winding 
up/down the levels would reveal terrifying looking faults in a lot of 
scanners..

Mark T.