From: martinm (martinm@SoftHome.net)
Date: 06/06/02-12:41:23 AM Z
Philippe, being equally active in the coating of holographic (red
sensitized) silver halide plates, I made some research about Lippmann
photography. It appears there are basically two main approaches:
one is coating plates/films with a liquid gelatin/silver halide solution in
the traditional way;
the second one involves bathing a gelatin (or casein, gum, PVA etc.) coated
plate in a silver nitrate solution. Subsequent to drying, the plate is
inserted into a halide/dye bath. The final step requires washing and drying.
I would like to learn more about panchromatic sensitization. I gathered the
choice of dyes is crucial and extremely subtle (particularly in regards to
compatibility and supersensitization).
Martin
> Dear Andy,
>
> I have been making holographic silver gelatin glass plates during 2
> years. I used then glass sheets made for LCD displays and notebooks. A
> glass manufacturer will certainly give you a 100 sheets sample for free.
> Indeed they produce so much glass of that kind that it should be no
> problem. In my case, I just payed the administrative costs.
> Once you have it, cut it to dimensions (tungsten carbide TOYO tip,
> diamond TOYO tip). Then wash it the right way (check in old books, soap,
> strong base, distilled water, sulfochromic bath, but I would definitely
> avoid that last one), rince with several distilled water baths and let
> dry away from dust.
>
> For making the emulsion, frankly speeking, make sure that you want to
> spend time on research. Controlling everything could take you years. But
> you can get results quite rapidly (contact me off-list). I now a Richard
> Maddox that might certainly help you too. Richard, are you there ?
> If you want orthochromatic or panchromatic emulsion, you'll need to get
> the right dyes, that are pretty expensive too (H.W.SANDS).
> Why not to consider making collodion plates in a first attempt, or
> "glass-calotype", or even liquid emulsion coating.
> For coating, choose the rod coating technique (see R.D.Specialties
> Rochester for the rods). I would start with something like a 85G rod.
> Always clean your rod with warm water directly after use.
>
> In summary, it's easy to make a basic silver gelatin emulsion, blue
> sensitive. It's also quite easy to have it ortho or panchro.
> What will be hard is your reproducibility and the shelf life or your
> plates. One needs to add stabilizers to keep it more than one week.
> So many parameters.
> But getting a first result will be fast.
>
> Wish you success,
>
> Philippe
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