Re: HP5/Rollo Pyro reciprocity

I believe Carl's conservative approach to HP5+ reciprocity correction
is wise because the last thing in the world we want to do when
developing with a Pyro staining developer is to over-expose. Unless
of course your idea of lots of fun is excruciatingly long exposures.

But in any event, HP5+ is really a very poor film for exposure in low
contrast lighting. Tmax 400 is a great film for these conditions if
you are working in 8X10 or smaller format. For ULF formats try Efke
PL 100. This is one of the best films I have every used for wide
expansion and contraction development. For a required density range
of 1.7 for kallitype and palladium printing this film with Pyrocat-HD
will cover SBR values from 11 to 5.3, all with reasonable development
times. In other words, for all practical purposes you could use it in
about 99.95% of the possible lighting conditions. You should be
able to come close with Rollo Pyro.

Sandy

>Bill,
>
>I've been developing in trays/PMK for several years, but it shouldn't affect
>reciprocity failure compensations.
>
>HP5+ specs call for less compensation than TXT. When developed to the
>contrast we want for Pt/Pd, even less compensation seems needed. At a full
>second I leave it alone. At two seconds I give it three. At 10 I give about
>20. At 15 I go to around 40, at 30 I go to 90 and at one minute I go to
>three. Beyond that, it's more like leave it open as long as practical, which
>is more or less what I've been doing with my pictures of drive-in theaters
>late in the evening.---Carl
>--
> Web site with picture galleries
>
> and workshop information
>
> http://www.carlweese.com
Received on Thu Mar 18 16:31:04 2004