Rodinal at 1+100 is it compensating?greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
Please let me comment on the dilute developers post as I have used Rodinal at 1+100 for at least 400 rolls of 36 exposure, 35mm film. NOTE: All of the following pertains to processing at 68 Degrees F. Agitation is continuous for the first 1 (one) minute, then 1 (one) complete inversion every minute. Agfa will email you a spec sheet for using that developer at 1+50 and 1+100. All of the times for various films at those dilutions are for 15 or 20 minutes. The time is determined on the exposure index (EI) recommended by Agfa. For example to use Rodinal at 1+100 and Agfa 400, the 400 must be shot at EI250. It is then developed for 20 minutes. This combination will give you a contrast index rating of .65. If you develop for 15 min you get a contrast index of .50 and you must rate the Agfa at 200. Various films respond to dilute Rodinal differently. You get a maximum speed of EI400 using Neopan 1600 in Rodinal at 1+100 for 20 minutes. If you shoot Tri-X rate it at 400 at 1+100 again for 20 minutes. So why, you may ask, would you use a developer like Rodinal at 1+100 if it inhibits a films full speed? Dilute Rodinal and Agfa 400 is extremely sharp (high acutanse (sp?)) and the grain (and believe me There Is Grain!) looks incredible. Combine this with very good shadow detail and you get a very high quality all be it grainy developer that is extremely economicalhere, in Vancouver, 500 mls of Rodinal, enough for 165 rolls of film, costs about $8.00 USD. That is less then 5 cents a roll! Now compare that to Ilfords new DDX or Kodak's TMax So my first question is has anyone used Rodinal at 1+200 or 1+300? Someone told me that they have heard of someone using it this way as a compensating developer. I'm kinda interested in using it for 120 TriX this way. I need a starting points for times and EI's. Second question can anyone explains to me in simple terms what a compensating developer is or does? When does it become a compensating developer? Oh yeahThird question: If I change the temperature from 68 degrees to 75 degrees thus reducing the developing times does this decrease the compensation effect? All The Best Jim Vanson
-- Jim Vanson (email@example.com), December 05, 1999
I would say that the compensating effect is based on exhaustion: after agaition there is a equal amount of developing agents per area, in the highlights the developer gets exhausted much faster than in the shadows. I used Rodinal 1:100 for about 40 mins with agaition once per 5 mins, so the highlights were actually for e.g. 8 minutes (assumming exhaustion after 1 min), while the shadows were developed for the full 40 min. Done at 200 C.
For a higher temperature, say 250C, the exhaustion is reached faster e.g. 40 sec instead of 1 min, as development is faster. So I would short the cycles from 5 to 3.5 min. With the same number of cycles (8) this would give about 28 min.
Instead of using even thinner Rodinal (1:200), UNLESS for Technical Pan, I would rather extend the time betwenn agaition, to increase the relation between shadow developing time and highlight dev. time. Thinned down Rodinal is running low on sulphite, a fact which increases grainsize.
-- Wolfram Kollig (firstname.lastname@example.org), December 06, 1999.