In article , Winsor Crosby <wincros@xxxxxxx> writes
>I thought the resolution of medium speed film was about 100 lines/mm. The
>CDW catalog I got today lists the resolution of the Coolscan II as 2700
>dpi. Since it takes two dots(one off and one on) to make a line its
>resolution would be roughly 50 lines/mm, if I am not mistaken. It might be
>close to the resolution of an inexpensive paper print.
Not quite true. 100lines/mm is the same as 100pixels/mm.
100line-pairs/mm (one black line and one white line) is 200pixels/mm.
These are frequently confused - not least in the photographic
literature.
So 100lines/mm is 2540dpi - hence the Coolscan II manages to resolve the
film grain with its resolution of 2700dpi. I must dig out some old PAN-
F and ortho negatives to see how it gets on with that, but it certainly
resolves the grain on 100ASA Kodacolor negative film and 64ASA
Kodachrome pretty well.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
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