### Rodinal

greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread

My question is: when I use Rodinal with "Ilford pan 100" the instruction on the cover of the film is to dilute 1+25. Now one film I need altogether 300cc. When I try to divide 300 to 26 I get some very difficult number = 11.53846153846 !! HELP!! Can anybody give me an easy way? Tnanks.

-- Daniel Baharal (dbaharal@zahav.net.il), February 04, 2002

use 15 ml Rodinal, 375 ml water: Pour of this solution 300ml in your tank. Or the whole 390 ml ;-)

-- Marc Leest (classicphoto@leest.net), February 04, 2002.

Go to your pharmacy and get a 10ml syringe. This is the easiest and most precise way to measure small amounts of liquid. I have used this method for a long time with Calbe R09 classic Rodinal developer.

-- Volker Schier (Volker.Schier@fen-net.de), February 04, 2002.

Using an oral syringe (available at drugstore, intended for measuring pediatric medications and such), measure 11.5ml of Rodinal, add water to make 300 ml.

There's no reason to carry the calculations out to more than three significant figures. 300/26 = 11.5, for all practical purposes. I'd expect that a quarter-degree's temperature change would cause more variation than that extra .03846153846 ml of developer.

Personally, I'd probably measure 300ml water, and add 12ml developer. That'd give 312ml total solution, but my measurements would all be nice round numbers.

-- Richard Cochran (rcochran@lanset.com), February 04, 2002.

I wouldn't develop FP4 (Pan 100 is FP4 from the edge of the production roll) in Rodinal 1+25. Better try 1+50, or even 1+75, 1+100. For the 1+50 dilution you should measure 5,8823529 ml of developer and add 294,11765 ml of water. I am kidding. Just measure 6 ml of developer and add some water to make 300 ml.

-- George Papantoniou (papanton@hol.gr), February 08, 2002.

12cc of Rodinal and 300cc of water gives you a 1:25 dilution.