Pixophrenic
Member
Geoffrey W. Crawley wrote in BJP 1960, issue of Dec 15: "Promicrol, by using glycin which as noted earlier has a slight solvent effect, in excess of sodium sulfite has a very high rate of physical development. Glycin, by itself, with modern films, provokes dichroic fog as soon as the concentration of sulfite rise above eight times its own concentration... the energized glycin does not provoke dichroic fog in the excess sulfite, a "sheen" however is produced similar to that given by borax alkalinity unrestrained"
Now, I know from practice, that a concoction with the following composition: metol 1.0 g/L, hydroquinone 0.5 g/L, glycin 0.5 g/L, sodium sulfite 30 g/L, sodium carbonate anhyd 2.5 g/L (pH 10.3), develops film in about the same time as D-76 and accumulates fine silver when used, despite relatively low sulfite and glycin. However, I do not see any dichroic fog, neither in FP4 nor in Foma 100, despite sulfite/glycin ratio exceeding the one predicted by Crawley to invoke dichroic fog, and perhaps I am overlooking the "sheen". The questions I have:
1. What does "sheen" look like and is it a weaker manifestation of dichroic fog?
2. Is there solvent action of some kind in the above concoction, which, however, happens in the absence of >75 g/L sulfite?
3. Am I to conclude that glycin is "energized"?
4. How can I provoke dichroic fog in this concoction?
Thank you very much for any ideas. If a similar discussion has already taken place, I'd appreciate a pointer.
Now, I know from practice, that a concoction with the following composition: metol 1.0 g/L, hydroquinone 0.5 g/L, glycin 0.5 g/L, sodium sulfite 30 g/L, sodium carbonate anhyd 2.5 g/L (pH 10.3), develops film in about the same time as D-76 and accumulates fine silver when used, despite relatively low sulfite and glycin. However, I do not see any dichroic fog, neither in FP4 nor in Foma 100, despite sulfite/glycin ratio exceeding the one predicted by Crawley to invoke dichroic fog, and perhaps I am overlooking the "sheen". The questions I have:
1. What does "sheen" look like and is it a weaker manifestation of dichroic fog?
2. Is there solvent action of some kind in the above concoction, which, however, happens in the absence of >75 g/L sulfite?
3. Am I to conclude that glycin is "energized"?
4. How can I provoke dichroic fog in this concoction?
Thank you very much for any ideas. If a similar discussion has already taken place, I'd appreciate a pointer.
.