Sheet film dev. in Tmax a no no??greenspun.com : LUSENET : Large format photography : One Thread
I read somewhere that sheet tmax 100 shouldn't be developed in Tmax dev but in Tmax r/s. Anyone have knowledge of this. I want to use sheet film and roll film at same ASA in one dev and I assumed the emulsion was the same. George
-- George Nedleman (GNLN@THEGRID.NET), April 28, 1999
Kodak claims a dichroic fog may occur using the T-Max developer and this problem does not happen with the T-Max RS. So if you are using sheet film then you should use the T-Max RS.
-- Jeff White (firstname.lastname@example.org), April 28, 1999.
You can use the RS for your roll film as well. It works just fine.
-- Dan Smith (email@example.com), April 30, 1999.
I've looked into this recently, because I love the TMax 100/TMax regular developer combination, and because Kodak's sensitometric curves show that the TMax regular developer is the best developer for this film. The following was related to me by a person within Kodak who helped drive development of the "RS" TMax developer.
TMax 100 sheet film is the same emulsion as TMax roll film. (The anti-reflective backing may differ a little.) As the source of the problem, TMax regular developer produces a by-product that can cause the dichroic fogging. Given sheet films' larger size, the fogging is more likely to occur with that film and much less likely to occur with roll film. (There's a greater chance of the by-product collecting and depositing itself on larger sized film.)
To solve the problem, Kodak designed the replenishable "RS" developer optimized for sheet film that reduces formation of the by-product. I have to commend Kodak, because they are also supporting the original developer.
As an alternative, the person I spoke with said that one can also try "finger-squeegee'ing" the film after washing, before it has a chance to dry. This removes the thin-film that can result from the by-product which causes the fogging. However, once the negative dries, if the fogging has occured, it's too late. It's a good idea to check this out for your particular developing process.
Given how much I like the regular developer, I've decided to opt for the alternative. Try this out and see how it works. (I only just spoke with Kodak about this problem.) In addition to preferring the regular TMax developer, I completed all my calibrations with the regular developer and I would like to avoid having to repeat them for the "RS" version.
-- neil poulsen (firstname.lastname@example.org), December 29, 1999.