John Walton wrote:

Get yourself a Texas Instruments or HP programmable calculator -- you can
take a look at the formula on Claudio's page (simplicity in itself.)
"Phil Glaser" wrote in message
om...
I'll try to beat Claudio to it and provide a link to his software page
http://www.bonavolta.ch/hobby/en/photo/labsoft.htm. The only thing
that this software requires a PC.

Claudio, any plans for a Palm version? That would help me out as I
could never fit a PC in my darkroom (not even a laptop).

--Phil



"rgans" wrote in
message . ..
Is there an electronic device, like the old HP Calculator, a palm pilot,
etc., and formulae which I can use in the dark room? For example, if I
determine that the exposure I want at 58cm is 12 sec at f/8, but then I
change the distance to 68 cm, how would I calculate the new exposure?
(I
know that light intensity falls off as the square of the distance) And,
if I
first decide to use Magenta=80 (on a Saunders LPL 45) but then go to
Magenta=120 Y=9, besides trial and error, are there formulae for
recalculating the exposure and is there a preferred device to make these
calculations on?

Thanks.

RON
__________________________________________________ _______________
B&W Landscape and Still Photography:
http://www.ronaldgansphotography.com
I still have a slide rule. Most of you may never have seen one. I don't
know where you might buy one, and I don't know who might teach you to
use one, but at least when I tell you I'm 76 years old, you'll believe
me.