Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Silverhalide Emulsions / Chemistry.
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thycore
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Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by thycore » Wed Jun 14, 2017 1:52 am

Hi folks,

I was fortunate to be sold by an understanding ebay seller this Holofilm ( we have no real idea of the type of holographic film, maybe it won't work at all or maybe it's only holographic foil which would just make some rainbows effect ), nevertheless, in the event of this being real holographic film in working conditions ( preservation state, still active since 20 years it's been enclosed in the sealed can ) ...
holofilm.jpg
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...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 ?

I could read in this (very interresting) publication, that this type of film was used in serial holographic copy (from a transmission master hologram), seems it might be the kind of film i'm looking for my learning of holography at low cost :
https://workspace.imperial.ac.uk/optica ... ns/PVH.pdf

Here below is an extract of page 283 :
publication.jpg
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So.... :-) ? any idea ?

lobaz
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by lobaz » Wed Jun 14, 2017 7:37 am

Hi,
the material is somehow described in "New Silver Halide Materials For The Mass Production Of Holograms", Glenn P Wood, Proc. SPIE 0615, Practical Holography, (20 August 1986); doi: 10.1117/12.961023. Unfortunately, the article does not give recipes for the developer and the bleach solutions, it only states:

"developer 2 minutes
stop bath 20 seconds
bleach 1 minute
final wash 2 minutes"

Some details on Ilford processing can be found in Hans Bjelkhagen's "Silver-Halide Recording Materials", chapter 3.3.4.:

"The Hotec developer is used diluted 1:4 and the developing time is 3 minutes with constant agitation. It is based on sodium-L-ascorbate and pentasodium DTPA (DiethyleneTriaminePentaAcetic acid). The Hotec bleach is of the rehalogenating type. The bleach is of a completely new type containing: dipotassiumferric DTPA, hydrobromic acid and sulfuric acid. It is supplied as a working strength solution."

I am not sure if it is worth to look for the original Ilford formulas. The film, as well as the dev & bleach, were intended for mass production of holograms, which means that the dev & bleach had to meet conditions you don't need, such as low toxicity, stability, ease of use of out the lab etc.

Petr

Din
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by Din » Wed Jun 14, 2017 8:47 am

I worked at Applied in the early 80's (about 1982). As I recall, we used D19 with either a fixer without hardener and a ferric bleach, or no fixer and a dichromate bleach. It was pretty much the workhorse developer at the time. I'm afraid I don't remember the formulations, but I'm sure someone here can list them.

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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by admin_jsfisher » Thu Jun 15, 2017 9:38 am

Din wrote:...I'm afraid I don't remember the formulations, but I'm sure someone here can list them.
There is always this: http://holowiki.org/wiki/Ewesly_/_Holographic_Formulae

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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by thycore » Thu Jun 15, 2017 2:03 pm

Thank you very much for your help !

I will test this Kodak D19 Developer formula :-)

Any clue for the Bleach ?
I'm pretty scared by the idea of using Sulfuric Acid xD as stated in Hans Bjelkhagen's chapter 3.3.4 !

Seems we have to aim for a Rehalogenating bleach type ?

Martin
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by Martin » Fri Jun 16, 2017 1:45 am

I gathered Ilford had acquired Applied Holographics in the mid 80s.
For their "SP" materials Ilford recommended ferric EDTA bleach for reflection and ferric nitrate for transmission holograms.

Ed Wesly
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by Ed Wesly » Fri Jun 16, 2017 7:05 pm

"...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.
WaffleSetUp.jpg
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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.
_MG_0980 copy.jpg
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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.
_MG_0980 copy2.jpg
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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 seehttp://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.
"We're the flowers in the dustbin" Sex Pistols

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thycore
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by thycore » Sat Jun 17, 2017 1:17 am

Many thanks for your impressive feedback, that's a lot of data to process for me now :-)

You wrote " So I simply laid the piece of film on the waffle iron without any holders or frames"... ehhhhh how could you prevent unwanted movements ? I tought I'd have to find 2 suitable glass plates to sandwich the film firmly ?

My laser is a HeNe 2.5mW, I have to count on "long exposure" times (10-12sec)

Ed Wesly
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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by Ed Wesly » Sat Jun 17, 2017 7:53 am

There is no need to worry about movement with a 20 nanosecond exposure time.
"We're the flowers in the dustbin" Sex Pistols

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Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Post by Martin » Sun Jun 18, 2017 3:50 am

Thanks, Ed.
I just reread Simon Brown‘s ”Techniques for making silver halide reflection holograms that can compete with photopolymers“ (SPIE 2176, 1994). It deals with the history of Applied Holographics PLC.
It looks like in their early years they had used reversal bleaching for mass-produced H3 copies (as you pointed out, to bring down the ruby-pulse laser exposed holograms from 694nm down to ~550nm).
They searched for better image brightness – after all, they wanted to compete with Polaroid‘s DMP-128 photopolymer. So they switched to rehalogenated bleaching. To control preswelling they used a liquid gate with isopropanol/water.
From that paper it‘s unclear to me what kind of AgX emulsion ”Holofilm 250 PAR“ is referring to. Over the years Applied Holographics had received different film batches from Ilford.
Incidently, I wonder if it‘s on a polyester support.

As for SP 672 and SP 673 materials in respect to transmission hologram processing Ilford‘s TECHNICAL INFORMATION, published in May 1986, says:
”When working with a standard developer such as Kodak D-19 or Tetenal Dokumol, it‘s important to bleach the film using a ferric nitrate bleach. The formula for this is given below.

Ferric nitrate 100g
Potassium bromide 30g
Water to make 1 litre“

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