Re: that old reciprocity failure question again

Shannon,
              Reciprocity corrections as well as development adjustments are
just suggested starting values, pretty much as the ISO speed of the films is
(i.e.: 4x5 TRI-X works for me as EI-200, and not as ISO320 as Kodak suggest).
From that perspective, both Kodak and the mentioned book are "correct". The
idea with any of this charts is to use them as starting point and make necessary
changes as experience/process you use requires.

Guillermo

----- Original Message -----
From: "Shannon Stoney" <shannonstoney@earthlink.net>

> Hi. I have two reciprocity failure charts. One is from Kodak and the other
> is from Steve Simmons' book, Using the View Camera. They give very
> different adjusted times for Tri X, when you get to very long exposures.
> For example, if the metered time is 30 seconds, Kodak says to expose for 200
> seconds, and Simmons says 290, almost half again as long. Also, the
> adjusted development percentages are very different. Kodak says 10% off
> even for an adjusted exposure of only 2 seconds, and 20% off if your
> adjusted exposure is 50 seconds, whereas Simmons doesn't even begin to
> decrease development until exposure reaches 13 seconds, and then only by 5%.
> If exposure is 50 seconds, he says to reduce development by about 9%. This
> is confusing. I wonder whose numbers are right?
Received on Thu Aug 8 23:05:43 2002