What is the purpose of stop bath? (Regards to Film)

What is the purpose of stop bath, and what will happen to your film if you don't use it during the development of Film?

The purpose of a stop bath is to quickly inactivate the developer by

changing the PH. This allows more precice development times. Also,

this will cause your fixer to last longer.

 

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If you do not use a stop bath, nothing will happen. Many

photographers do not use it and some developers (Pyro for example)

work better without it.

Keith:

 

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An acid fixer will stop the chemical reactions of the developing

agents the same way an acid stop bath does. As a matter of fact, in

an old darkroom instruction book that I have, acid fixers are

referred to as "stop-fixers". If some sort of stop bath isn't used,

however, problems can arise. Excessive developer carry-over can

cause stains, and changes in the pH level of the fixer can reduce the

fixer's effectiveness.

 

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If an acid stop bath isn't used, it is still wise to use a water

rinse between developer and fixer. It would also be wise to moniter

the pH of the fixer as well as periodically check film clearing

times. For large-volume work, it might be necessary to replenish the

fixer periodically.

An acid stop bath can cause pinholes in the film if used following a

developer high in carbonate (such as Paterson developers and other

high acutance formulas). The safest thing is to use a water rinse

before the fixer. I fill the tank three times and agitate for about

10 seconds each.