Hi, all.
A slightly OT question for you darkroom wizards...
I'll try to get some pictures of the Transit of Venus, so I need a solar
filter. Since a 'real' one is impossible to get here (at least, on time),
I'll use a fully darkened strip of 120 B&W film (*not* chromogenic!!!).
Back to the solar eclipse of 1999 I made my filters that way, and it worked
properly -- pics came OK and our retinas weren't burned ;-)
Now it's time to look for a film-developer combination which achieves my
two goals:
*Pretty high optical density (D=4-5 would be fine for the camera, but I'd
prefer something like D=6 for naked eye observation)
*Clear base, in order not to impair *too much* image sharpness and
resolution -- I know I can't expect miracles here, though.
Back in 1999 I had the weird TXP (quite different from our beloved Tri-X,
TX) *way* overdeveloped on HC-110 under intense lighting. I no longer have
the stips, nor the development data :-(
This time I'm trying with Ilford Pan-F (not 'plus') and Ilfotec DD-X. For
'normal' use, I find the Pan-F (plus?) base quite clear, and IIRC this film
achieves a rather high D-max.
However, my first experiments (DD-X 1+9, 20 min @ 22C / 72F) don't look to
have a very high D-max. Any guidelines for increasing D-max?
Should I be concerned about the film's exposure? This time I had the film
facing the sun for about half a minute, and developed it in an open tank
(indoors). I've heard that a severe overexposure may 'reverse' the fogging
and reduce D-max, is that true?
I may sacrifice a roll of 120 Technical Pan, would that be much better?
Thanks a lot in advance!
Enjoy,
...
Carlos J. Santisteban
<cjss@xxxxxxxxxxxxx>
<http://cjss.galeon.com>
The olympus mailinglist olympus@xxxxxxxxxx
To unsubscribe: mailto:olympus-request@xxxxxxxxxx?subject=unsubscribe
To contact the list admins: mailto:olympusadmin@xxxxxxxxxx?subject="Olympus
List Problem"
|