Has anyone come up with a better method than TEA? I tried today with household ammonia diluted 10:1, the initial result looks hopeful. I've heard about methods using mercury and methods using high pressure nitrogen and hydrogen. Any other ideas? I need to hypersentize in a 100% humidity enviroment (caves).
Guillermito - Sun, Sep 24, 00 07:38:28 AM
I think i read somewhere (cannot remember where) that hydrating the plate by just pure water, just before the exposure, was working fine for enhacing the sensitivity of the film (but not for shifting the wavelength, of course). My only try with TEA was totally ugly. By the way, is raw TEA a powder or a liquid? I did a try with some powder i found in my lab, and when the plate dried, the TEA crystallized everywhere on the plate :)
132.183.191.178
Vidar - Thu, Oct 05, 00 03:22:19 AM
Sure, pure water will remove the preservative in the film, making the reply wavelength even closer to the original laser wavelenght if you use a master developer. The method is useful if you need to use the same reply angle as the original master setup. The film will also be about twice as sensitive compared to a not-washed film. My tea results was also ugly, but I did not have any crystal problems. The tea I used was a liquid. 195.70.188.204
Guillermito - Thu, Oct 05, 00 06:33:34 PM
Thanks Vidar for the response. Hey, sensitivity enhanced twice with just water, that's pretty good! I will try whenever i have the time. For the TEA, i just had a look on Sigma chemical catalogue, and actually the powder is the hydrochloride form of TEA. Which means that it may not only be very acid when diluted in water and ruin the gelatin, but the high quantity of chloride ions may perturbate the development chemical reaction. The liquid form is just the free base, which have a neutral pH, and of course no chloride ions. So usable for our holographic purposes. Actually, i should have checked that, because the TEA they sell at Photographer's Formulary is the liquid form. I may try a 7.5 % concentration, like your tries with Ronny (BB-640 / diode) which are really impressive. Oh, and by the way, i'm still interested to buy a copy of your Nuts and Bolts hologram! :)) 132.183.191.178