sodium metabisulfite stop

[Colin Graham]

In looking for a mild stop bath for pyrocat and the famously tender efke emulsions, I have been trying a 3% solution of sodium metabisulfite. I havent been getting the scratches or pinholes that I got with acetic acid but I'm also wondering if it's still acidic enought to effect the stain. (I've read that a plain water rinse is best for pyro but this wont work well with my setup.) Any thoughts on the suject greatly appreciated

 

[gainer]

I'd be more concerned about the sulfite, but not much in either case. Why not use water as stop? If you don't mind being a little extravagent with fixer, use TF4 and add the concentrate directly to the developer at the end of development time. 1 ounce of TF4 concentrate (shake well before using) to 8 or so ounces of developer works well. Both the developer and the fixer are one-shot this way.

 

[Colin Graham]

I'd be more concerned about the sulfite, but not much in either case. Why not use water as stop? If you don't mind being a little extravagent with fixer, use TF4 and add the concentrate directly to the developer at the end of development time. 1 ounce of TF4 concentrate (shake well before using) to 8 or so ounces of developer works well. Both the developer and the fixer are one-shot this way.

You've turned my world upside down. Is this really possible? The less I have to shuffle the negatives from tray to tray the better

 

[Kirk Keyes]

Here's an aproach that I'm sure will be unpopular as it is very much out of favor these days, but, how about using a harding stop bath and harding fixer? Hopefully you will not have as many scratches. Fixing times will be longer, but you can still use a hypo clearing solution to shorten the washtime when compared to using water alone.

In my single test of using a water wash for stop bath vs. using actual stop bath, I found a very minimal difference in stain density. And I attribute the difference to the continued action of the devloper in the water wash instead of a loss of the stain due to the acid in the stop bath as the red and visual channel density of the film was slightly greater on the water bath film compared to the stop film.

I would suggest a test run to make sure you get the desired affect from the hardening baths and that you don't lose any stain with your film.

Kirk

 

[nworth]

Water works very well as a stop for film. I use one quick rinse followed by a second rinse of about 30 seconds. I prefer a slightly acid fixer, however, to prevent unwanted stains. For fussy emulsions like EFKE (I've had my share of problems with them too), be careful that the water is well filtered (to avoid even small pieces of grit) and that it is the same temperature as the other solutions (to avoid reticulation or related separation of the emulsion). These factors are also a concern in the wash, especially if you do not use a hardening fix. Despite the longer wash needed, I suspect the EFKE films can benefit from hardener, although this can be a touchy issue for pyro users. During the wash, make sure the films do not bang or scrape against one another. I usually just keep mine in the tank.

I've recently had some problems with scratches appearing after the wash. They were either picked up during the final rinse step (my primary suspect) or somehow during drying. Any ideas?

Two other possibilities for a stop bath: an acetic acid-sodium acetate buffer solution at pH 6-6.5; a chrome alum hardening stop.

 

[avandesande]

I use a teaspoon of citric acid in a liter of water. This works fine with efke. I just toss it when I am done.

 

[Ole]

All fixers will stop the developing! Acidic fixers stop by neutralising the alkaline developer, alkaline by removing undeveloped silver halides. The reasons for using a stop bath are

A: predictable, repeatable stopping - only relevant if you let your fixer get old:
B: lower the pH in the emulsion in preparation for the acidic fixer, to prevent reticulation from "ph shock" - but most stop baths are far more acidic than any fixer!
C: washing the developer out of the emulsion, so the fixer lasts longer.

I see no reason to use an acidic stop bath at all. Nor do I see a reason for using a very acidic fixer?

 

[Tom Hoskinson]

I develop my Efke 100 in Pyrocat-HD (in a slosher Tray - and sometimes in ABS tubes). with the slosher I go directly from the Pyrocat into the TF-4 fixer. With Tubes, I do the same. I have never experienced problems with pinholes or scratches in the emulsion.

With Efke 100 120 rollfilm I develop in a tank. Recently I've been using a variation on Pat Gainers trick - after development is completed, I add a dollop of 60% Ammonium Thiosulfate solution directly to the remaining developer in the tank, then I wash and dry the film - no problems so far with emulsion pinholes, scratches, nicks or dings.

I do not handle the film while it is wet with any of these processes.

 

[fhovie]

TF3 is a pH of 8. No shock there. A little water to help make it last longer and no worries. - Tray processing - I ALWAYS scratched my negs. I went to the hardware store and bought a long 4" black plastic pipe, caps, unions, some glue and a sheet of black rubber. One hour later (and about $25) I had 4 processing tubes. NOW I can watch stargate and develop 8x10 sheets. Life is Sweet!