I just made my first syringe-pumped emulsion, using this controller and a prototype mechanics. It was actually just a single-run (silver nitrate run from a single syringe), but I'm really surprised how easy and nice the procedure was. Actually I was browsing Internet in the next room most of the time while the syringe pump made the emulsion for me . The silver solution for 150 ml of emulsion fit nicely in one 50ml syringe, and the pump controller took care of additions, waiting between additions etc.

Then, I quickly chilled the emulsion on my newest invention, AntiStove, which is just like electric stove but it cools down by using Peltier elements. . Maybe I have to automate washing next, now it's the most tedious phase left!

I went to Photograde cow bone gelatin (from Photoformulary), left the ammonia out as a test (to reduce the odor), increased the temperature from 42 to 50, otherwise using the same bromo-iodide formula I've used before, with Jim Browning's dye transfer matrix film silver addition profile. This resulted in a fogless, nice around 1 ISO emulsion (completely unsensitized).

My actual purpose in addition to testing my new equipment and photograde gelatin, was to try using Congo Red (cheap indicator grade) in methanol (it seems to form a fine colloid or dispersion at 1% both in water or alcohols) as a green sensitizer. I added 200 mg/mol(Ag) (because the dye content is 40% in indicator grade) and stirred at 45 degC for 10 minutes and coated instantly after, but didn't notice any sensitivity rise in green region --- exposure to yellow light from enlarger resulted in 3 stops underexposed test, just like with unsensitized one. I'll try higher amount (this emulsion is probably quite fine-grained with high grain surface area) and longer treatment next. Replacing erythrosine with something that can be added in the finals would be nice.