Sorry about the dye/pigment confusion. Must have head in two different places at once. "Back in the day" I worked with pigments, not dyes.
We don't even have to worry about 3rd and 4th order diffrations, as they will overlap starting at 300 nm and 225 nm respectively.
To get back to AgX spectral sensitizers, here's another link: http://www.organica.de/en/Products/49,Functional_Dyes
03910 and 03930 look like possible candidates. Look for structures like those but with less steric hindrance.
Hello Ron and All,
Recently, I have been working with an emulsion that is higher in I:Br ratio than I have worked with previously. As I have written here befor, I work with Ron's suggestion of DSA3057 (red senisitizer due to J aggrigates) and SDE 3008(green sensitizer). By total accident, I have found that the SDE3008 is acting as both a green and red sensitizer. Also the degree of sensitivity to all 3 colors is very even. There are several differences between this emulsion and what I have worked on befor. And, like all of my emulsions, it uses silane treated PVA instead of gelatin. But the latter could NOT be the reason for the accidental Red sensitivity, as I have been working with silane treated PVA emulsion almost as long as I have been working with emulsions.
There is another R&G sensitizer , or so I am told, that I will also be trying
I have slowed down lately and will be taking a "leave of absense" from "wet work" for 6-8 weeks due to upcoming surgery. But right now, I am taking the above emulsion, which I HAVE been able to replicate and scale up, and try to improve the coating chracteristics. As of now, containing no sufactant at all, it leaves random craters when coated onto very clean glass.
Best of luck to you all,
Thanks for the update Bill. The behavior that you see is not unusual. It is probably due to Iodide concentration on the different grains, or on the absolute concentration. If it is the latter, then the sensitivity will gradually shift towards being all red if you up the concentration slightly. But, OTOH, either mechanism is ok. It really does not matter. Repeatable success is what counts.
Best wishes on the surgery and may your recovery be swift and complete.
Thanks,PE-Here are two examples. When you judge the coating quality, please remember that I am working in total darkness with only a cheap night vision monicle to see with. I cannot realy see my coating until after the fix. The glass plates were exposed at f11 for 1 and 10 seconds.
Who am I to complain. I hide all of my bad coatings in a big big box. ;) Believe me, I know how hard it is.