Thank you, Ron!
Of course halide excess is norm. And such emulsions don't meet any veil troubles. I often overwashed my normal emulsions till pAg=7-8 and all worked good. But now I am especially interesting in low pAg emulsion and read one ancient work by Carroll and Hubbard (1928), who were successful enough in silver excess gelatin emulsions. But they could have the centrifugal separation (of course I can't), that give some advantages. All I can do is to follow they strict limitation they worked out by empirical tests - do not raise pH higher 3,5.
"...but we find that if the hydrogen ion concentration of the emulsion is increased well above the isoelectric point (pH preferably 3.5 or less), and deactivated gelatin is used, such emulsions may be kept for at least a month without noticeable increase in fog".
Of course the silver excess is to be not too large. Carroll's emulsion have Ag-excess "the same order as the excess soluble bromide in a normal emulsion." (normal washed emulsion meant).
Last edited by diant; 11-03-2011 at 03:20 PM. Click to view previous post history.