From: Kevin Won (wonk@ohsu.edu)
Date: 08/18/03-03:50:25 PM Z
Thanks for the reply. I have your book and took the 70 degrees as my starting point. (I thought that for 80 I would develop 30 seconds less for each degree difference to start = 4 minutes using your 9 minute at 70 suggestion) However, my thought process is (a) I have an ATL2 processor which can bring my chemestry up to 80 degrees, (b) my recirc bath temeprature may be difficult to cool down to 70 (my workspace in in an attic and currently even with AC is 76) so I'd like to standardize on a temp that I can be assured I can always obtain (the ATL2 as I'm sure you know can raise the temp well but isn't so good at cooling unless you buy a cooler). So I was thinking that if there weren't any reasons not to, I would standardize on a hotter temp.
I'm going with the Rollo premix from B&S because I don't want the powder pyro around (I have a son). Hopefully I'll be able to run enough film through my new processor before my chem updates!
Kevin
>>> cweese@earthlink.net 08/18/03 01:44PM >>>
Kevin,
Looking it up in TNPP, I find I recommended that TMY be developed in Jobo Expert drums for nine minutes at 70 degrees in ABC+ (rollo) pyro formula to produce negatives intended for platinum/palladium printing. I did that testing about six years ago so it should be used as a starting point only: do your own tests with fresh materials.
With a convenient nine minute time I see no point in raising the temperature. The ABC+ formula itself takes care of the oxidation problem--that's what the formula is for. Using ABC+ is a little more tricky than using PMK in trays. The stock solutions should be allowed to mature for a couple days after mixing, and the mixed amount should be used up in a few months because it tends to gain activity after that. The working solution is of course a one-shot.
---Carl
--
Web site with picture galleries
and workshop information
http://www.carlweese.com
From: Kevin Won <wonk@ohsu.edu>
Reply-To: alt-photo-process-l@sask.usask.ca
Date: Mon, 18 Aug 2003 12:52:08 -0700
To: alt-photo-process-l@sask.usask.ca
Subject: TMY dev time for rollo at 80 degrees?
I just purchased a Jobo and will be using it to dev negs bound for Pd. printing in expert drums with rollo, which I've never used. I'd like to use the developer a little warmer if possible. Questions:
(1) Is a higher temp (80 deg or so) a good idea? I'm thinking that with the oxidation of pyro that it might be better to user it hotter and expose it less to the air.
(2) if so, what's a good starting point to dev time?
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