Looking for dyes, additives or a formula to sensitize collodion to >800nm (infrared)
After reading the giant thread 'A real formula' with PE in the Forum: Silver Gelatin Based Emulsion Making & Coating, I'm a little confused.
There are lots of hints ond advices for dyes to create an emulsion with superpanchromatic or, at least, expanded red or infrared sensivity. But these formulas are all just for dry plates.
My collodion plates are just sensitive to blue light.
After production of Kodak HIE was stopped and there was no other real infrared film material on the market anymore (forget Rollei and SPX, just 700nm / EFKE and Konica stopped production) there is no chance to continue real infrared photography.
So I just wanted to try some dyes to expand/shift sensitivity up to 800 or more nm with collodion wet plates.
The wet collodion process is devided in two parts.
1. The collodion
2. Sensibilization in silver nitrate sol.
Where, when, how and how much do I have to add the Neocyanine or the 3,3'-Diethyloxatricarbocyanine iodide.
Do I have to change the developer (iron(II) sulfate), then?
How about fixing, then? Any experience?
...and sorry about my horrable English!
I suppose you would then have to sensitize the plate in total darkness then. When you sensitize with neocyanine is beyond me. Time for you to start experimenting... and spending heaps of money! Those dyes are not cheap!
Use APUG Search Engine. There are hundreds of posts invested on that subject. Or surf the APUG threads , many of them are at archive dungeon.
Originally Posted by Andrew O'Neill
well, I already sensitized my plates in the darkroom tent in a small box with silver nitrate sol. (inside the box in complete darkness).
So I hope, after a few tests there won't be need for any further check views on the plate.
But I actually still don't know how much and which dyes to add, how to develop then (still just iron (II) sulfate sol. in darkness - what time then) and how to fix then.
Maybe here is someone else, who tried it - I hoped it's worth asking here ;-)
Maybe you're right and in the end I will need to try it alone the whole rocky way...
Uhm... no Mustafa, there are no combined results for 'collodion' and 'infrared' in the search engine (It was my first try) for APUG forum posts... (so why do you claim the opposite?)
Originally Posted by Mustafa Umut Sarac
That's why I asked the community.
Do you want me not to ask anymore?
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I found that there was no reply to your post and wanted to help. Post thousands of posts in time , I read and answer if I could.
Your post was first to find a answer on collodion sensitizing for infrared. I am following the forum since 2006 and never saw one.
But there is red , green , panchromatic sensitizing posts , many.
May be you can learn from these posts. In my experience , patents and old books are only references.
Try to private message to Ian Grant or Photo Engineer and ask their opinion.
I googled and found a patent. I took some part referencing many important patents.
The infrared sensitizing dyes to be used in the present invention can be directly dispersed in the emulsion. Alternatively, they may be first dissolved in a suitable solvent such as methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine, or a mixture thereof to add them to the emulsion as a solution. Processes for adding the infrared sensitizing dyes to the photographic emulsion are described, for example, in U.S. Pat. Nos. 3,469,987, 3,676,147, 3,822,135, 4,199,360, and in U.S. Pat. Nos. 2,912,343, 3,342,605, 2,996,287 and 3,429,835. The aforesaid infrared sensitizing dyes may be uniformly dispersed in the silver halide emulsion before coating on a suitable support. Of course, this dispersing procedure may be conducted in any suitable step of preparing the silver halide emulsion.
Infrared sensitive silver halide color photographic elements for use in the present invention are preferably those described in U.S. Pat. No. 4,619,892, which is incorporated herein by reference. More preferably, the infrared sensitive silver halide color photographic elements for use in the present invention are those having all of the silver halide emulsion layers sensitized to different infrared regions of the electromagnetic spectrum. The order of these layers respect to the support, the difference in emulsion sensitivity among the layers and the sensitivity, contrast and D-max of each layer are preferably those described in said U.S. Pat. No. 4,619,892.
Any of the various types of photographic silver halide emulsions may be used in the practice of the present invention. Silver chloride, silver bromide, silver iodobromide, silver chlorobromide, silver chloroiodobromide, and mixtures thereof may be used, for example, dispersed in a hydrophilic colloid or carrier. Any configuration of grains, cubic, orthorombic, hexagonal, epitaxial, or tabular (high aspect ratio) grains may be used. The colloid may be partially hardened or fully hardened by any of the variously known photographic hardeners. Such hardeners are free aldehydes, aldehyde releasing compounds, triazines and diazines, aziridines, vinylsulfones, carbodiimides, and the like may be used, as described, for example, in U.S. Pat. Nos. 3,232,764, 2,870,013, 3,819,608, 3,325,287, 3,992,366, 3,271,175 and 3,490,911.
Last edited by Mustafa Umut Sarac; 05-13-2013 at 03:33 PM. Click to view previous post history.
AFAIK, there are no examples of dry plate, wet plate or Daguerreotype plates in the literature. I know that they were worked on at EK and at RIT many many years ago.
I'm not saying it is impossible, I'm saying that some concerted work by a lot of people was not successful. It may be that with more modern dyes, it might work.
Who produces these more modern dyes ?
H.W. Sands Corp www.hwsands.com manufactures many types of imaging dyes and chemicals.
Be prepared to part with a LOT of money ($ hundreds/gram). Some dyes are very costly, and there can also be a "convenience fee" attached to small orders.