Pyro developers

[Shootar401]

I've been thinking of trying some Pyro developers for Foma 200 and other films. Some things I've heard is that I shouldn't use Photoflo with Pyro, hypo-clear and I would need to wash the films for 20-30 minutes.

Are these just rumors or is there some truth to it?

 

[ROL]

Sheet film? I do not use photoflo with any sheet film/developer, which at this point is only PMK Pyro – only a final distilled water rinse after washing. I do use photoflo with all roll films.

 

[Regular Rod]

I've been thinking of trying some Pyro developers for Foma 200 and other films. Some things I've heard is that I shouldn't use Photoflo with Pyro, hypo-clear and I would need to wash the films for 20-30 minutes.

Are these just rumors or is there some truth to it?

This is very good and keeps for years. http://freepdfhosting.com/aa330a94ce.pdf


Page 2 shows how I use it. http://freepdfhosting.com/3e906fe75d.pdf and this is the device I prefer http://freepdfhosting.com/f640343f29.pdf

I use Mirasol one drop in 500 ml is plenty (possibly too much) EDWAL LFN gets good reports but not available in UK...

RR

 

[nworth]

I haven't had any problems with a Photoflo rinse after catechol development, as long as the rinse is sufficiently dilute (half a cap per liter). I don't normally use HCA, but it contains a lot of sulfite and EDTA. I doubt if it would attack the stain much, and I haven't heard any really credible reports that it does. But some experimenting might be in order - two identically exposed and processed sheets, one rinsed with HCA and the other not.

 

[TheFlyingCamera]

I use PhotoFlo with my pyro-developed films with no observable adverse effect even after five or six years. I do NOT use HCA of any kind, though. Just plenty of water wash - I use the Ilford 4,3,2,2 method (4 minutes, change water, 3 minutes, change water, 2 minutes, change water, 2 minutes, dump and into the PhotoFlo).

 

[Sirius Glass]

I use PhotoFlo with my pyro-developed films with no observable adverse effect even after five or six years. I do NOT use HCA of any kind, though. Just plenty of water wash - I use the Ilford 4,3,2,2 method (4 minutes, change water, 3 minutes, change water, 2 minutes, change water, 2 minutes, dump and into the PhotoFlo).

Wot he said.

 

[Gerald C Koch]

There does not appear to be any chemical in Photo-Flo that would have any adverse effect on film processed in pyro developers. Photo-Flo contains as the active ingredient Triton X-100 which is a surfactant which reduces the surface tension of the water. The remaining ingredients are an anti-foaming agent and propylene glycol.

 

[Dave Swinnard]

I've been using both a HCA (Na Sulphite based) and Edwals LFN for quite a few years now without any observable issues. (On 35mm, roll, and 4x5 films of various sorts)

 

[Gerald C Koch]

The stain created by pyrogallol and catchol consists of what are called humic acids. These compounds consist of condensed phenols, think of chicken wire for a visual picture of their structure. Once formed the higher weight ones are insoluble in water. They are relatively impervious to most chemicals. However exposure of stain negatives to UV light can cause bleaching. A method for intensifying a weak negative consists of repeatedly bleaching the image using a rehalogenating bleach and then followed by redevelopment in a pyro developer. This process can be repeated over and over again for increased density showing just how tough these images are.

 

[Doremus Scudder]

I do use Photoflo with sheet film. It's the last rinse in distilled water before hanging to dry. I use PMK almost exclusively now, and have never experienced and problems with staining or image degradation.

Best,

Doremus