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View Full Version : Dye sensitization by soaking dried emulsion - dye testing on the cheap



Kirk Keyes
09-12-2008, 09:29 PM
The thread on panchromatic emulsions touched on this concept - has anyone here tried or know of some resources that discuss this technique? I've found this from Ryuji Suzuki,

"Although I discourage you to go this route if the motivation is the
apparent cost, this may be the only option in some cases. The
procedure is to make a very dilute solution of infrared dye of
suitable kind, usually in methanol or other solvent, and immerse the
film in thie bath for a certain amount of time (typically 1-3 minutes)
and dry, all in total darkness. This works the best with undyed or
"color blind" material, but it is reported to work with commercial
panchromatic films."

See more at http://www.usask.ca/lists/alt-photo-process/2004/jul04/0339.htm

Athough Ryuji says cost is not a good reason to try this, I think it actually may give a good, quick indicator as to whether to proceed with a specific unknown dye before taking the time to actually make a full-fledged emulsion using the aforementioned dye.

While a film like Ilford Ortho+ sheet film would not allow one to test green sensitive dyes, as it is already green and blue sensitive, it would allow for testing red and IR dyes.

Kirk

wildbillbugman
09-12-2008, 11:17 PM
Kirk,
Would it not be just as cheap, and almost as easy, to make a simple blue sensative emulsion, coat it on sheats of paper, cut the paper into strips and stick it in the freezer. You could then just take out as many strips as you have dyes,for green or red sensitization, soak the strip in a dilute solution of the dye,dry, then place the apropriate filter over part of the strip,expose and develop? Yes, that's called a run-on sentence.
Bill
I did not "score" this AM. But I found out that the gangsters and other tough guys will leave you alone if they think that you are truely insane.
Bill

Kirk Keyes
09-13-2008, 01:01 AM
Bill, yes, that could be done - whether you did it with a run-on sentence or not. But I was trying to find a way to do it with one less step than making an emulsion. It seems like the sensitometry variation when comparing home-made emulsion vs commercial film would be mimimixed with the commercial product.

I'm sure when Ron swings by, he'll remind us about how you can get odd behaviours with different dyes, such as the one he mentioned that was red and green from the same dye, but different when used with different types of emulsions.

But i'm curious if anyone has tried this around here.

Kirk Keyes
09-13-2008, 01:01 AM
Bill, that crazy routine is a good one when around those guys.

AgX
09-13-2008, 12:42 PM
Aside from considering the original spectral sensitization of the proof material any differences in crystal structure too should be of influence, among other things.