Here's a question for the photochemists out there: Is there any reason why rapid fixers (Hypam, Kodak Rapid Fix et al.) cannot be used at higher dilutions for film than the recommended dilution (usually 1:4), and if so, what would be the increase in fixing time, if any? Does using more dilute fixer have an effect on the way film fixes? I would think, that if it works for paper, it should work for film as well.(posted 8604 days ago)My thinking is this: If I can use a higher dilution of fixer for film, making sure I have enough stock solution for the amount of film I am developing, then I can use it one-shot. This is especially useful when developing on the road. I do 4x5 in trays, and could then reduce my developing paraphernalia to three trays and stock solutions of developer and fix. The fixer, used one-shot, could be discarded along with the developer after use. This would be more economical, eliminate having to pack a bottle of working solution fixer, and eliminate problems with shelf life of the working solution (Ilford says 7 days for mixed Hypam), particularly useful for those of us who don't process larger quantities of film at a time.
My preliminary tests with unexposed Tri-X and BPF-200 film indicate that the clearing time for conventional films is less than one minute. Following my usual rule-of-thumb and fixing for three times the clearing time would result in fixing times quite close, if not identical, to that used for the stronger dilution. How would using fresh, highly diluted fixer compare to fixing in almost-used-to-capacity normal-strength fixer? Any thoughts, ideas for tests etc., would be most welcome.