development of the film may continue unevenly in the fixer solution, resulting in streaks.
The importance of adequate rinsing cannot be too strongly emphasized.
c. Opalescence. Sometimes a film viewed immediately after fixing in a fresh
solution appears opalescent. This is a transient condition, disappearing when the film is
washed and dried. It is caused by the reaction of the gelatin of the emulsion to the high
concentration of sodium thiosulfate in the fixer. This condition frequently occurs when
the solution has been freshly mixed.