Ian - I think a lot of the recent popularity of the notion of using water baths is a combination of the "Book of Pyro" suggesting the use of the alkaline afterbath (used PMK developer) and Anchell and Troop's "Film Developer Cookbook" recommendation of an "all alkaline" film development process. Bill Troop suggested the use of waterbaths instead of stop bath with his alkaline fixers.
The plain water rinse stage,was once the norm, it goes back beryond the early days of the first dry (gelatin) plates, but these were dish developed or in racks and a water rinse was quick& easy, and efficient enough.
So historically a plain water rinse has long been understood to work, Film emulsions were far softer pre 1960's but by then Pyro developers or the older film developers like D72 had gone out of mass use.
The advent of 35mm and slow working carbonate free developers meant an acid stop bath could be used safely without fear of pinholes, and manufacturers began recommending them.
People are giving far to much importance to the Stop bath stage, it's "superfluous" as Mason states in Photographic Chemistry, and Kodak & Fuji think so too as they use no stop or rinse in their Roller Transport B&W processes.
Anyone making posts in this thread needs to take that into account before attacking the notion of using a water rinse instead of a stop bath, it makes all their statements farcical.
Rational discussion of the benefits/disadvantages are quite different.
All I can say on my own behalf is that, I do not disagree with what Kodak or any other mfgr says. They say either can be used for film. They say that a stop should be used for paper.
PE
Summing up
- A stop bath is not necessary at all, neither is a water rinse.
Mason states clearly the stage is superfluous to the overall processing of films or papers, and this is also backed up by both Fuji & Kodak who include no rinse or stop in their mechanic film processing data & Ilford who state that there should be no problem in machines with no facility for a stop bath. That's for films and RC papers.
Needs very good agitation to prevent dichrioc fogging.
We are talking about using a stop bath or water rinse not leaving the stage out:
- A stop baths purpose is not the removal of all residual developing agents. There's insufficient time, this will continue during fixing and washing.
- The purpose of a water rinse or stop bath is the slowing of development, which is more immediate with an acid stop bath
- The second purpose of a water rinse or stop bath is minimising the carry over of developer into the fixer.
- The advantage of a stop bath is that the pH of the film has been changed, so helping preserve the buffering of the (acid) fixer, potentially prolonging the fixers life & throughput.
- Stop bath is detrimental with some soft emulsion films with certain developers, due to pin hole issues.
- If no stop bath is used there have been reports of Dichroic fogging before an Alkaline/Neutral fixer, but in numerous threads Ron (PE) has always recommended the use of a stop bath before TF-4.
It's up to people to decide which of the manufacturers recommendations they use water rinse or stop bath
As Steve says:
The manufactures really know what they are doing. Follow the directions.
Steve
They recommend either, and historically the water rinse is the older and in just short 140 years hasn't been shown to be less effective particularly in terms of the long term stability of the film. There can be benefits for fixer life etc using a stop bath though.
There's a reference to Ansel Adams earlier in the thread and yet many of his great negatives and those of Edward Weston were made using a water rinse not a stop bath so take that into account in your choice.
Ian