Posted: Tue Jul 18, 2006 11:43 am
Acetic acid Stop Bath has no chemical reaction with developer that will result in white specs. Aluminum dropping out of fixer hardener because it is improperly mixed, results in white specs.
Film Photography & Darkroom Forum
Skipping the stop bath causes the fixer to deteriorate quicker. It also causes the formation of specs.Lowell Huff wrote:Acetic acid Stop Bath has no chemical reaction with developer that will result in white specs. Aluminum dropping out of fixer hardener because it is improperly mixed, results in white specs.
Carry over of developer does indeed harm the fixer.Lowell Huff wrote:Developer carry over does not cause fixer to deteriorate. The purpose of stop bath is to stop development.
Modern fixing formulas are buffered against pH change. That being said, acid, neutral or alkaline pH of fixers has no scientificly measureable effect on fixing. It is thio sulfate the combines with the un developed silver and as long as there is "thio" available it will fix. As the fixing solution saturates, fixing speed slows down but even a super saturated solution will continue to fix, it just takes longer.
You can look this up in any good photo chemistry book.Lowell Huff wrote:How does it harm fixer? What is the chemical reaction that harms fixer?
Use stop bath, and rapid fixer with hardener.Lowell Huff wrote:I have for years, told our customers that they did not need a stop bath if the were using our fixers because they are stop- fixes. I also have recommended for years, not using hardener.