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Re: [APML] Agfa Optima Prestige film
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>>>>> "Bert" == Bert Katzung <katzung1@comcast.net> writes:
Bert> I've never used Optima Prestige, but recommendations of
Bert> daylight photographers, professional or otherwise, are
Bert> generally worthless for astro applications. The reciprocity
Bert> characteristics of films are generally unknown to them (and
Bert> sometimes to the manufacturer as well, when it comes to 1
Bert> hour exposures) and reciprocity is critical for our stuff.
As a small footnote to this, I recently picked up a book on large
format photography. Interestingly enough, it has a set of charts
showing reciprocity adjustments for a large number of films. The
chart only extends to about 120 seconds (nominal, the adjusted
exposure may be much longer). So *some* professional photographers
are at least aware of the problem. Too bad Kodak, Fuji, Agfa,
etc. don't publish similar charts....
regards,
roland
- --
PGP Key ID: 66 BC 3B CD
Roland B. Roberts, PhD RL Enterprises
roland@rlenter.com 6818 Madeline Court
roland@astrofoto.org Brooklyn, NY 11220
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