I noticed that some emulsions posted on this forum have a first step where the AgNO3 is combined with Ammonia. The emulsions I make are very fine grained (grain sizes less than 20nm) and are intended for holography. The sensitivity of my (red sensitive) emulsion is very low at the moment and has to be increased before exposure by immersing the emulsion into a solution of dilute developer. I would like to increase the sensitivity of my mix without using the gold sensitizer because it causes grain growth. My question is: Is the Ammonia step done to increase the sensitivity of the emulsion? If that is the case, does the SRAD procedure encourage grain growth or is it still possible to make ultra fine grain emulsions with it?