On 10 Nov 2007 at 1:16, Ryuji Suzuki wrote: > From: George L Smyth <glsmyth@xxxxxxxxx> > Subject: Re: Kodak Discontinues HIE and Other Films > Date: Fri, 9 Nov 2007 13:58:09 -0800 (PST) > > > Actually, I have a feeling that Kodak uses a different dye > > to get the film to go as far into the infrared as it does, > > Indeed, but - > > > so they would probably have to use a completely different > > formula for the emulsion. > > This is not necessarily true. > > It is possible to use a general purpose negative film emulsion > with a range of inrared dyes. Indeed, although not optimal, it > is possible to soak regular b&w film emulsion in IR dye > solution and sensitize it to IR exposure. (Don't think about > doing it to save money, because it doesn't. But after seeing > Konica IR 750 and HIE go, I may have to look into this option > more seriously!) > > On the other hand, one thing I totally do not understand is > why none of the European IR films use better dye for fine art > b&w photography. They may be originally made for traffic > severance, aerial photography or similar volume users but once > these users are gone they are free to use better dyes for our > purposes... The IR-dye that Kodak has been using for HIE seems to be a very tricky substance: http://www.a1.nl/phomepag/markerink/ir_infrared-sensitive-component.txt Btw, could an IR(only)->visible fluorescent/luminiscent (=momentarily vs accumulating-continuous-decaying) substance be any solution, or would that already be the essence of any IR-sensitive dye? (hmm....a luminiscent component could be tricky, unless the decay-curve matches the exposure(index) exactly....:)) All comments & pointers are very welcome....more than once in the past, when browsing old books about IR&UV, I had the feeling that there might be quite some old info buried in them, not being revealed to the modern generation of scientists (or components/processes back then dismissed for reasons that could be solved quite easily today). In addition to that: I very seriously doubt that Kodak has done much elementary research in this field over the last 5-10 years (despite the reshuffle/split of Aerochrome IR, for 2 different grades of altitude/bluetone), as such investments could never be justified with the decaying sales, even to the industry. That said, the Russians had an IR-film that had even higher IR-sensitivity, but as one would expect, storage/shelf-life became increasingly tricky as well. Not even sure if that same company exists today, gotta dig out my old PhotoKina files.... (they did carry a lovely range of odd-ball (perforated) bulk-roll formats, of which hardly anyone in the west ever heard off....gotta love military applications....:)) PS: I have been in close contact with Mr. Schroeder from Maco on this subject, over the years, predicting that production of HIE would be ended rather sooner than later....and that is also where this story about IR-sensitive components, and their shelf-life/economies-of-scale, comes from. (and he wasn't too enthousiast about what the Russians did either, IIRC; still not sure if they used a higher concentration of the same stuff, or a completely different component) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand <w.j.markerink@xxxxx> [note: 'a-one' & 'en-el'!]
