Re: LPM on Negative (TECH-3D digest 219)

[T3D Bob Howard <bobh@xxxxxxxxxxxxxxxxxx>]

RE: John Ohrt asks how one can discuss lpm on negative without 
considering degree of enlargement???
I think this is implicit in 35mm and some large format photography as 
assuming a final print needing only 7 lpm for eye to look at.
Eg. Weston's 8 x 10 contact prints didn't care if diffraction at f/64 
limited resolving power to 11 lpm or less as only 7 needed from 
viewing contact print.
In 35mm work the original Holy Grail was to make a 5x7 print that 
would resemble a large format contact print! This perhaps today is 
now 8 x 10 or larger. So 80 lpm in neg at 10X enlargement would give 
8 lpm in print (assuming no loss in enlarging lens!) BobH
(I can't imagine a "portrait photographer" wanting 1600 lpm optical 
resolution to get something very high on film? :-)   )


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