"...Any people here who would, by chance, have worked on this material already and have an idea of the kind of chemistry which is involved in developing and bleaching ? "
Here are my experiences with this material from September of 2016, and the stuff worked well and was not fogged, being at least a quarter of a century old or more. I am rather fortunate in having the type of laser the film was designed, a pulsed ruby from JK. So I got out the old waffle iron, (see
http://edweslystudio.com/Pedagogy/TS/St ... ectTS.html for the significance of the iron), cut some 8” by 240mm sheets of the roll, (240mm is the width of the roll, and my darkroom cutter is calibrated in inches) and started making exposure tests. (See
http://edweslystudio.com/Pedagogy/TS/Te ... meset.html.)
This film is on a very thin stock, that’s how they get 400 feet in a cylinder that would hold only a 100’ of the usually found 3 mil (75 micron) substrate. In its original application it would have been laminated to some sort of support, like bumper stickers or the hologram in the Saxby third edition. It’s a feature, not a bug, as it l lies flatter than the thicker stocks when cut off the roll. So I simply laid the piece of film on the waffle iron without any holders or frames.
Here's the set up, the waffle iron is on a storage shelf across from the laser. That is the flash of the ruby compared to room light, captured using the ruby laser like a photographic strobe triggered by my trusty Canon 40D. See
http://edweslystudio.com/Publications/I ... Paper.html for details.
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Exposure is a function of intensity times time, (E = I X t), and the exposure time of a pulsed ruby laser is set at 20 nanoseconds in Q-switched mode. To vary the exposure dosage the output of the laser is determined by how hard the amplifier is driven, so a series of shots were taken of the waffle iron in a spread beam at a variety of settings, from 1.6 kV to 2.4 kV in 100 Volt increments.
The first batch was developed for 2’ in the developer specifically and accidentally formulated to combat High Intensity Reciprocity Failure, SM-6. See
http://edweslystudio.com/Formulae/Developers/SM6.html for the straight poop. They were bleached in the classic silver solvent reversal dichromate bleach of the PyroChrome Process (
http://edweslystudio.com/Formulae/Bleac ... leach.html.
To see if there would be any improvement by monkeying around with the development time, one sheet was exposed and cut into three strips, developed for 2, 4 and 6 minutes. The finished test strip exhibited the expected downshifting toward green with greater developed density, as predicted in
http://edweslystudio.com/Formulae/Developers/CWC2g.pdf and
http://edweslystudio.com/Formulae/Bleac ... leach.htmllinks.
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I compared the classic Fe EDTA bleach formula to the "Chrome bleach in another divided sheet. (Heck, I've got 400'!) The HoloPar didn't seem to like it.
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The Hotec rehalogenating bleach mentioned above came out with a later reincarnation of Ilford holo products. (I call the materials from the '80's and '90's Ilford, the contemporary stuff Harman.) Solvent bleaching was intended for use on the HoloCopier production lines to get the shrinkage for replay at shorter wavelengths than the deep red of the ruby, 694nm, which is right at the edge of visibility. All the samples I've ever seen of HoloCopier product were green. I also attempted bleaching in one of the PBU Ultimate Organic Bleaches, (sorry, I don't have a link to it!) which used Ascorbic Acid as the oxidizer precursor, and you'll have to take my word for it, it was too snowy to even bother photographing. So I've given up on rehalogenating this one, although it's my go-to bleach for the SP Ilford products.
I did try this film with CW lasers, and it worked OK in the transmission case, about one stop slower than Agfa 8E75HD. For these holos, I used Harman/Ilford Phenisol, which I had a sample of, which is their D-19 like formulation, followed by the 'Chrome bleach. Don't have photos readily available, but rest assured this stuff does work! When I revisit this mode I will probably use one of the Kodak D-19 variations (
http://edweslystudio.com/Formulae/Developers/D19.html) or CWC2 (
http://edweslystudio.com/Formulae/Developers/CWC2.html).
“There is always this:
http://holowiki.org/wiki/Ewesly_/_Holographic_Formulae”
Be careful with this link! Some of the formulae are corrupted! Go straight to the source,
http://edweslystudio.com/Formulae/Devel ... meset.html.
"I'm pretty scared by the idea of using Sulfuric Acid xD as stated in Hans Bjelkhagen's chapter 3.3.4 ! "
Don’t sweat it! You can use a dry form of sulfuric acid, called sodium bisulfate in the states, sodium dihydrogen sulfate in the UK. And it’s easy to find, believe it or not! Go to a store that sells supplies for pools and spas, and it’s found in the section of the chemistry that raises and lowers pH. It’s the main ingredient in the one that lowers pH, and if you are looking for sodium carbonate for developer chemistry that’s the one they use to raise pH! Use 3 grams of the bisulfate for every milliliter of sulfuric acid that the recipe calls for. Can you believe people soak themselves in it?
“I gathered Ilford had acquired Applied Holographics in the mid 80s.”
No, they did not. What’s left of Applied Holographics is part of OpSec, and I may be out of date on that. But for sure Ilford is still in business, having been bought by Harman Technology.
https://www.harmantechnology.com/ And they did make holographic plates in this century which are decent, if you consider a drop in replacement for the old Agfa 8E75HD decent. You
can make decent single beam reflection holograms on their green material, a feat Agfa 8E56HD was never capable of. For details see
http://edweslystudio.com/Research/AllHologramsF12.pdf Takes a while to download, but it's worth the wait. Good luck finding any of the plates!
"For their "SP" materials Ilford recommended ferric EDTA bleach for reflection and ferric nitrate for transmission holograms."
Yes on the Fe EDTA, never on the Ferric Nitrate.
So that's about all I know about this stuff.