Pyro + Hardening fixer

[Nasser]

Thank you all for the helpful posts.... Ken, I am using Alford HP5+

[sanking]

Ian,

Definitely a lot of mis-information out there from people who should have known better. And could have know better with just a bit of decent testing.

Sandy

Well slightly less avaiaable with the demise of EFKE, and they were the films which would benefit the most fro a hardening fixer. When I began using EFKE films in the 70's the lack of hardening was far worse, I used to use a Chrome alum hardening stop bath (a Kodak formula) or add a few drps of Formaldehyde to my developer.

There was a lot of rubbish written about staining dedvlopers by some well known people. They used to advise putting film back in the deveoper after fixing as that re-0inforced the staining, all mit dis=d was add more base stain.

I use a staining print developer occasionally and the stain is not affected at all by acidic solutions, films aren'y either. So 110% what Sandy says.

Ian

[Michael A. Smith]

I am surprised that anyone is using PMK who is making contact prints. Even Gordon Hutchings himself, I was told, does not use it for negatives that will be contact printed. The yellow stain from PMK, whether put back in the developer or not is a general stain. As such, it does not increase contrast. Properly stained negatives will only look stained when compared to a non-staining developer. Looked at alone, they appear to have no stain at all.

I went back to the Azo Forum and will take the liberty to quote here from DJ (Nayakanakuppam Dhananjay) from a post on August 16, 2002. http://www.michaelandpaula.com/mp/Az...4&GID=47&CID=2

There is much more in the Azo forum concerning this, but DJ's writing is essential, I think.

The recommendation of placing the film in an afterbath consisting of the used developer is due to the fact that acid inhibits stain formation. Most folks tend to use a fixer that has hardener and is acid. This inhibits stain formation. By placin the film in an alkaline afterbath (the used developer), you provide an alkaline environment that encourages stain formation. I don't know if the after bath causes general stain (rather than image stain) - in my experience, general stain is more due to aeriel oxidation.

Whenever pyro oxidizes, it will stain the gelatin. If the oxidation is due to reduction of silver, one will get image stain (i.e., proportional to silver density). However, if oxidation is due to aeriel oxidation, this will lay down a more or less uniform stain across the entire geltain matrix (i.e., general stain). General stain is problematic because it reduces shadow value separation and thus film speed.

PMK was designed as a pyro developer that maximises staining properties, something which is useful if you are enlarging (with the big grain of pyro, you want all the help you can get from stain to combat the grain). However, grain is not a concern in contact printing, and one is better off using more moderate staining formulae like ABC, which are more consistent and less problematic. With PMK, you do have to fight to avoid aeriel oxidation, epecially if you use the frothy rotary agitation. For contact prints, a robust formula like ABC is probably considerably less trouble and will provide all the desirable properties of pyro (high local contrast with low overall contrast) without having to combat a bunch of problems related to general staining (aeriel oxidation, uneven staining etc).
Cheers, DJ

Michael A. Smith