Compensating Developmentgreenspun.com : LUSENET : Large format photography : One Thread
During the two years that I have been into large format photography I have avoided extreme contrast situations (greater than n-2), because there was just too much else to learn. On a recent week long backpacking trip to Utah I decided not to pass up some excellent photos because of this. I now have a few negatives I'm not sure how to process. Bruce Barnbaum's book has some excellent starting points for tri-x in hc-110 and for t-max in t-max rs, however, I would prefer to continue my t-max in hc-110 endeavers in this area if possible. Do any of you more experienced folks have some numbers to get me going with c(n-3), c-, c-- and c--- for t-max in hc-110. I would prefer a two solution procedure, but one solution would be good as well. Also , perhaps some estimates on how many stops to open up for each. I know I have to fine tune this stuff for myself, but this seems to be way more complex than establishing film speed, normal and push and pull develpment times. Just a little direction would be greatly appreciated to get me going in the right direction. Thanks.
-- Paul Mongillo (email@example.com), September 19, 2000
Two bath developers are compensating and will only develop the highlights to the optimum. Diafine will give a 1 stop speed increase whereas Divided D76 will keep your speed without any loss or gain. They both are fine grain (very) with Diafine higher in acutance. There are to many opportunities that, as you even stated yourself, are missed. With a few compensating developers to choose from in your darkroom, there will be no reason not to take these photos!!! I have alot of recipes that I can send you or you can get a few commercially available split baths that should not be over looked. Cheers
-- Scott Walton (firstname.lastname@example.org), September 19, 2000.
Paul there was an article which appeared in View Camera a while back relating to pyro development and a technique called 3 over 2. That is you expose the shadows 3 stops above your normal placement and cut back on development by 50%. You don't take highlight readings when using this technique because apparently this would scare you.
I've not used this technique myself yet but have come close to it and have had excellent results with pyro at N-2, N-3 and more recently with DiXactol used as a single bath but can be used two bath for a more compensating effect.
-- Trevor Crone (email@example.com), September 19, 2000.
TMX works great in HC-110 if you thin the developer out to about 1:30. You will probably need about 15 minutes for normal, so plan on maybe 9 or 10 to start with. I have done about -3 at 12 mins. by spreading out the agitation toward the end of the time by a couple minutes. Don't run too much film through the devloper, though, there is not much developer in there. Probably a one shot batch. If you have not developed your trip photos, just make about three negs. in the yard and do them at once for three different times to see what you get. You should get enough of an idea to be able to do the real ones next.
-- E.L. (firstname.lastname@example.org), September 19, 2000.
Yeah! What E.L. says. HC110 works very well with the TMax films. But be careful in two regards. If you didn't give extra exposure for the shadows(Z3>4) then I wouldn't go beyond N-2 because even though the shadows don't move much, they do move and you may end up with printable highlights at the expense of empty shadows. And TMax films don't have a thick emulsion so be careful with any type development schemes that rely on developer uptake by the emulsion. Dilute developer and an agitation scheme that gets longer toward the end is the way to go. I second the notion of going out in your backyard and taking a few test shots of a 6 or 7 stop range subject and practicing on those first unless you can get back to the places you went and take some more shots. James
-- james (email@example.com), September 19, 2000.
Has anyone tried doing N-2 or greater contractions with dilute HC110 using rotary processing?
-- Chris Patti (firstname.lastname@example.org), September 20, 2000.
Pyrocatechin (catechol) is often touted for its compensating qualities, due to the tanning effect it has, which is directly proportional to the amount of exposure. Adams gives a nice formula in 'The Negative'. Sandy King has published a new formula called Pyrocat-HD, which uses phenidone and pyrocatechin, that I think is worth experimenting with. DiXactol is said to be a glycin and pyrocatechin formula, and being a two-solution developer should have strong compensating effects.
-- Ed Buffaloe (email@example.com), September 22, 2000.
Chris, once you get to N-2 I would start pick another method of processing your film. I use rotory and at N-1.5 the highlights become too dense no matter what your developer dilution. I go to hangers because I can control agitation schemes better. In extreme SBR conditions I use a very dilute developer and start with vigorous agitation the first time and then drastically reduce agitation until I'm at a point of just letting the film stand with no agitation at all. If you have these SBR problems I would use some pre-exposure and then some selenium toning after development. That's worth 1.5+ stops right their. Masking is also an option. If using PYRO as a developing scheme make sure to give extra exposure so the pyro has some silver to work on otherwise that tanning ability only yeilds empty grey shadows with no detail. James
-- james (firstname.lastname@example.org), September 24, 2000.