Re: Can I leave film in stop bath for 7 minutes? Depending on the developer and fixer choices, plain water could be an acceptable stop bath which would certainly be harmless to leave it in several minutes.
DO you have room to move them from the stop bath to a water holding bath? In general, getting the film into the fix ASAP is preferred as the film swells to it's max the thickness in the developer, shrinks a little while in SB, and much more in the hardening fixing bath, so the emulsion is in it's most fragile state after development, so best to keep it moving through the process If you need a hold, better after the fix in wash water Steve K.
Originally Posted by Drew Wiley. Some films are way more sensitive than others. I find that this level of concentration is unnecessary, since I never reuse the bath.
The exact degree of dilution is not critical, but I mix it about a quarter that strength. Indicator stop bath is helpful; in that case, I dilute it to barely yellow. And in predicaments like yours, leaving a few sheet a couple minutes longer in the stop, while still developing the remainder of the sheets, seems to have no ill effect.
But I am very careful to stack the code notches differently, and never develop odd lots in equal numbers where they might get confused. Originally Posted by Richie. Richie, You don't say how you develop although you do mention tanks.
With tray processing, it's easy just to add sheets to the developer later. I routinely develop, say, N and N-1 together, adding the N-1 sheets a couple of minutes into the developing.
My agitation is once through the stack every 30 seconds. If you are developing film on hangers and doing dip and dunk with an initial longer agitation and then agitation every seconds, it would seem easier to do as you suggest, i.
I can't see where an extended stop bath would do any damage at all. The pinholes mentioned above are not from extended time, but rather the formation of gas bubbles due to the reaction of an extremely alkaline developer with a strong stop in which case, a weaker stop is indicated. If I were you, I'd simply go that route. Dispose developer in "Waste Developer" tank. This process can be customized depending on your need or the film you are using.
Agitate continuously Return used stop bath to bulk tank This process stops the action of the developer, and prevents fixer from rapid exhaustion. Agitate for first 30 sec, then for 5 sec for every 30 sec.
Drain used fixer to bulk tank. Film is no longer light-sensitive after this process. The job of fixer is to remove the unexposed silver halide. The developer has already reduced the exposed silver halide. However, over time even without developer the remaining unexposed silver halide will become exposed and change color. The fixer removes this unexposed silver halide from the emulsion. This process runs to completion.
Once gone it's gone. There is considerably leeway in the length of the fixer bath because not much happens once the unexposed silver has been removed. However, eventually other things happen like the emulsion or backing starts getting dissolved or excessively water-logged, which can soften it and make it more susceptible to scratching until finally dried again. I've also heard not totally sure this is true that more of the salts in the fixer slowly diffuse into the substrate, which makes properly rinsing the film or paper more difficult and longer.
This would imply that excessively long fixing times can be offset be longer washing times, but again, I'm not sure about this. Of course the chemists that designed the paper and chemicals thought about all this and distilled it down to a set of easy to follow instructions.
The best thing for you to do is to simply follow them. Unless you're a chemist specializing in this area, I wouldn't try to get creative. There may be unintended side effects, some possibly long term. The stop bath usually dilute acetic acid or even water neutralizes the developer and stops the development process almost as soon as the film becomes in contact with the stop bath.
There is no point to continuing the stop bath any longer than this, but it will do little harm when development occurs in perfect darkness. When developing with a safelight, you want to minimize the amount of exposure to the safelight until the fixing has started, so you want to make the stop bath time as short as possible and get the film or print into the fixer right away.
The same neutralizing effect also happens without a stop bath, if you were to go straight to the fixer, but then a great amount of the fixer would become "exhausted" and requires you to use fresh fixer much more often. Therefore use only as much time in the stop bath as is needed to be sure the film has come in contact with it, usually 15 - 30 seconds.
Often that's the time it takes just to pour the stop bath in and then out of a developing tank. If you leave a film or print in the fixer too long , I recall reading that it can oxidize : it will turn brown and lose contrast. It might be interesting to run a few experiments with blank film strips or bits of photographic paper. There is a lot of latitude, though; my experience is that most fixing occurs within the first few minutes or even seconds, with fresh fixer at a high temperature and you can keep film or prints in the fixer for ten times as long without harm.
The difference between 5 and 7 minutes is of no consequence. Can grain be afected by longer stop bath? Thank you. Rodinal is a very highly alkaline developer more so than most others , and is more affected by the use of an acid stop bath than most developers.
Going directly from Rodinal developer to an acid stop can cause pinholes no wars please and other anomalies such as increased grain.
This process cuts down the degree of shock going from a high alkaline state to a highly acid state, while at the same time helping to prolong the fixer solution.
Ditto Mark's comments. I usually start with a plain water rinse, followed by a rather weak stop bath. I figure a stop bath isn't really critical when development times were longer than 5 minutes. And a stop bath is practically irrelevant when the development time was 10 minutes or longer. Thanks Mark and Lex, that could explain the increasing grain.
I am going to try the water bath instead acid bath and see what happens. How much time do you recomend for the water bath? I have also noted some dark spots in two frames, but not sure if they are the pinholes you mentioned before or handling marks. I will tell you the results.
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