Silver Processing Formulas

This is a collection of chemistries for holographic development and holographic film manufacture. For the definitive source about holographic development please purchase a copy of SILVER HALIDE MATERIALS FOR HOLOGRAPHY AND THEIR PROCESSING by Hans Bjelkhagen ISBN 3-540-58619-9. Contact Integraf for JD-2, JD-3, JD-4, SILVER HALIDE MATERIALS AND THEIR PROCESSING by Hans Bjelkhagen or for Slavich Film. Many of these chemicals are very dangerous. Please don't breath the dust or fumes. Make sure to wear gloves and don't pour the used chemicals in your drain. Your drain goes to someone's drinking water! Don't forget to read and follow the MSDS.

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Notes on Mixing Chemistry for Silver Halide Materials The order and methods you use for mixing is very important. Normally you add in the order of the formulation. Some of these formulations are likely to be out of order.

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TJ1

TJ1 Developer - By Jeff Blyth

JD-2

from Integraf for PFG-01 from Slavich

Solution A

• Distilled Water 100 Deg. F 750 ml
• Catachol 20 grams
• Ascorbic Acid 10 grams
• Sodium Sulfite 10 grams
• Urea 75 grams
• Water 68 Deg. F 1 liter

Solution B

• Distilled Water 100 Deg. F 800 ml
• Sodium Carbonate, Anhyd. 60 grams
• Water 68 Deg. F to make 1 liter

Mix equal parts A and B just before development. Mix enough for one hologram only. (I have developed 3, but the first one is best)

Bleach

• Distilled Water 68 deg. F 750 ml
• Potassium Dichromate 5 grams
• Sodium Bisulfate 80 grams
• Water 68 deg. F to make 1 liter

Dissolve potassium dichromate completely before adding sodium bisulfate. The bleach can be used for a long time. At least 5 months shelf life.

• Develop 2 minutes
• Rinse 3 minutes
• Bleach till clear (less than two minutes)
• Rinse
• Photo flo
• Air dry

JD-3

from Integraf

Developer Part A

• Water 750ml
• Catechol 20g
• Ascorbic acid 10g
• Sodium sulfite 10g
• Urea 75g
• Water to make 1L

Part B

• Water 750ml
• Sodium carbonate 60g
• Water to make 1L Bleach
• Water 750ml
• Copper sulfate 17g
• Potassium bromide 55g
• Succinic acid 2g
• Water to make 1L

Post Treatment

• Water 300ml
• Ascorbic acid 10g
• Water to make 400ml

Mix equal parta A and B. Working solution has a life of 8 hours. Only develop one hologram. Develop for 2 minutes with agitation. Soak in distilled water for 10 seconds. Wash for 3 minutes. Do not dilute bleach. Bleach emulsion side down till clear. Less than 2 minutes. Wash for 3 minutes. Dilute post treatment 1 to 10 with water. soak under bright light until the hologram turns from pink to light brown. Wash for 3 minutes.

JD-4

from Integraf for PFG-03M from Slavich

Developer Part A (1 liter)

• Metol or Elon (p-Methylaminophenol sulfate) 4 g
• Ascorbic acid (powder) 25 g

Developer Part B (1 liter)

• Sodium carbonate, anhydrous 70 g
• Sodium hydroxide 15 g

Bleach (1 liter)

• Copper sulfate (pentahydrate) 35g
• Potassium bromide 100g
• Sodium hydrogen sulfate crystals 5g

Mixing instructions
Use three l liter (or larger) size clean glass or plastic bottles with leak proof caps. Label them A, B, and Bleach respectively. Warm the distilled or de-ionized water to about 40o C (warm to the touch). Fill the bottle marked A with 700 ml of warm water. Dissolve the Metol in it, then add the ascorbic acid. Add 300 ml of warm water to make 1 liter of Part A developer. Tightly cap the bottle. Part A will oxidized if it is exposed to oxygen. In time (over a few days to few weeks), the solution may turn yellow due to the oxidation of ascorbic acid; the solution is still useable. Once the solution turns dark brown, the potency is lost and should be disposed. One way of protecting it from oxidation is to subdivide the solution into smaller bottles so that the unused portions are in fully capped bottles, with little or no air space on top. Refrigeration also slows down oxidation (exercise extreme caution to prevent its mistaken identity as food). Follow the same procedure for Part B (add the sodium carbonate and sodium hydroxide in either order). This solution will keep for many weeks. Follow the same procedure for mixing the Bleach. This solution has very long shelf life.

Hardener - Slavich

• Formalin 37%
• 10ml Potassium Bromide
• 2g Sodium Carbonate
• 5g Water to 1L

Fixer - Slavich

• Methyl Phenidone 0.2g
• Hydroquinone 5g
• Sodium Sulphite(Anhyd.) 100g
• Potassium Hydroxide 5g
• Ammonium Thiocyanate 12g
• Water to 1L

Metol-Ascorbate developer

courtesy of Laser Reflections The formula is as follows: Metol-Acorbate Developer (Part A + Part B)

Part A:

• Metol 10g
• Ascorbic Acid 80g
• Water to 1000ml

Part B:

• Sodium Carbonate Anhydrous 120g
• Sodium Hydroxide 14g
• Potassium Bromide 4g
• Water to 1000ml

Use it in combination with a Fe-EDTA bleach - a safe, stable bleach which has a long shelf life.

Fe-EDTA Bleach

• EDTA (2Na) 30g *Fe(III) Sulfate 30g
• Potassium Bromide 30g
• Sodium Hydrogen Sulfate Crystals 30g
• Water to 1000ml

Russian Emulsion Tips

From Jeffrey: When using Russian emulsions - Pre-develop gelatin hardening bath - Sensitizes and maintains colors, allows squeegee use

• Distilled water 750 ml
• Formaldehyde 37% (Formalin) 10 ml (10.2 g)
• Potassium bromide 2 g
• Sodium carbonate (anhydrous) 5 g
• add distilled water to make 1 L

Processing time 6 minutes. Developing times may increase with harder gelatin.

CWC2

From Jeffrey: CWC2 DEVELOPER and PBU-AMIDOL BLEACH - for all types of HOLOGRAMS CWC2 - two-part

DEVELOPER PART A solution

• 500 ml. warmed distilled water.
• (Pyro)Catechol 10 grams
• L-Ascorbic Acid (Vitamin C) 5 grams
• Sodium Sulfite (anhydrous) 5 grams
• Urea 30 grams

PART B solution

• 500 ml. warmed distilled water.
• Sodium Carbonate 30 grams

Part A is good for one month, Part B indefinitely. Add equal parts A & B to activate just a minute or two before use, just enough to cover one hologram. Mixed solution is active for 20 minutes. Discard after one use to assure each hologram has optimum development. Develop time:at least TWO minutes @ 68 degrees F. with constant agitation (AGFA). FIVE minutes for low power lasers, for HRT plates and PFG-03M plates. Rinse in distilled water. View a green safelight through rinsed plate to judge density - some variation is OK. Adjust exposure/developing time to achieve a final developed density of:

• D 1.5 - 2 - medium gray (for an unbleached transmission hologram)
• D 2 - 3.5 - very dark (reflection holograms).
• D 4 - appears mostly opaque (good for HRT reflection holograms).

Do not use fixer if it will be bleached (reflection holograms are usually bleached). Notes on developed density - this stage is where you figure if exposure, ratio, gleam spots, beam centering, even illumination, and overall light levels and their recorded patterns are OK for the next shot as well, or need adjustment. After the plate is bleached clear, these clues are gone. Although dark, wet, and hard to see, observation of different gray levels is important, hopefully understanding what caused each visible pattern. A good safelight is important. My favorite is a commercially available four-foot fluorescent fixture with plastic tube filters.

PBU-AMIDOL re-halogenating BLEACH

(Phillips Bjelkhagen Ultimate)

• Potassium Persulfate 10 grams
• Sodium Bisulfate (or Citric Acid) 10 grams
• Potassium Bromide 20 grams
• Cupric Bromide 1 gram
• Amidol (- add last ! -) 1 gram

Mix one at a time, in sequence, into 500 ml. warmed distilled water, then add another 500 ml. distilled water to make 1 liter.

• Wait at least 30 minutes for chemical activation.
• Bleach unfixed plate for 3-5 minutes @ 68 degrees F. 'til clear + 2 minutes. Rehalogenating (and image brightening) continues after clearing.
• Rinse, rinse, rinse in distilled water.
• With a drop of Photo-Flo in the final rinse, squeegee.
• Air dry, a low-heat blower or drying cabinet for around 15 minutes - not too fast, not too slow.

An acetic acid rinse after bleaching may help reduce print-out (the emulsion will darken a bit after you run out in the daylight to see your image). I prefer to avoid intense sunlight until aged a few days. Re-bleaching later will partially clear a darkened plate and give some immunity to further print-out. Bleach can be re-used a few times, and is usually good for two weeks - red color will fade to clear, indicating exhaustion. *Beware sediment as it ages - do NOT attempt to re-mix before each use - decant and do not dump dregs out onto emulsion.

• Bleach will leave permanent purple stains on everything - handle carefully !

Many thanks to Cooke and Ward, Hans Bjelkhagen, Nick Phillips and Ed Wesly for the many trials to attain the basic formulation.

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GP-9

• Phenidone .026 g
• Hydroquinone .665 g
• Anhydrous Sodium Sulfite 13 g
• Potassium Hydroxide 1.38 g
• Ammonium Thiocyanate 3.12g
• Distilled Water 1 L

GP-61

Transmission

• Distilled Water 700cc
• Metol 6 g *Hydroquinone 7 g
• Phenidone .8g
• anhydrous sodium Sulfite 30g
• Anhydrous Sodium Carbonate 60 g
• Potassium Bromide 2 g
• Sequesterine Agent 1 g *Water to make 1 L

GP-62

Reflection (use Bleach)

Part A

• Distilled Water 700 cc *Metol 15 g
• Pyrogallol 7 g
• Anhydrous Sodium Sulfite 20 g
• Potassium Bromide 4 g
• Sequestrene Agent 2 g
• Water to make 1 L

Part B

• Distilled Water 700 cc
• Anhydrous Carbonate 60 g
• Water to make 1 L

Kodak D-8

• Ascorbic Acid 18g
• Sodium Hydroxide 12 g
• Sodium Phosphate Dibasic 28.4 g
• Distilled water 1 L

Just before use add Phenidone .5 g

Transmission bleach

• Water 1 L
• Potassium Ferocyanide 1 tablespoon
• Potassium Bromide 1 tablespoon (or Cupric Bromide 1 tablespoon)

Reflection bleach

• water 1 L
• potassium Bromide 30 g
• Borax 15 g
• Potassium dichromate 2 g

Just before use add PBQ (p-benzoquinone) 2 g (good for 15 minutes)

PBQ

• Water 1 L
• Mercuric Chloride 1 tablespoon
• Potassium Bromide 1 tablespoon

or

• Water 1 L
• Potassium Bromide 30 g
• Boric Acid 1.5 g
• PBQ 2 g

Good for only 15 minutes!

or

• Sulphric acid 1 g
• potassium Bromide 5g
• Methyl Paraben 2g
• Hydrogen Peroxide 4 g (you have to figure the weight of the Hydrogen peroxide in you solution!)
• Potassium Alum 5g (hardener)
• PBQ 1 g
• Phenosafranine 1g (desensitizer)

GP-431 Bleach

• Water 600 cc
• Ferric Nitrate 8-hydrate 150 g
• Potassium Bromide 30 g
• Dissolve .3 g of Phenosafranine in 250 cc of methanol and then add.
• Water to make 1 L

Dilute 4 parts water to 1 part gp-431 before use.

Leroy

by Martin Since some are interested in the old Leroy paper, here is my - rudimentary - translation: Excerpts from: M.N. Leroy, Préparation et sensitométrie de plaques photographiques à grain très fin (plaques pour la photographie interférentielle), Paris 1929

Summary

The following note presents a new way for the making of fine grain photographic emulsions, derived from colloidal silver, that allows for the spectral recording of remarkable brightness, comparable to Lippmann emulsions. It (the note) summarizes certain results achieved with silver chloride, bromide and iodide. The study of the density graphs indicates a maximum sensitivity at a particular lambda for each of the three cases and depends on the molecular weight of the specific salt used. Having established the characteristic graph of each emulsion at certain spectral levels, the author is studying the variation of gamma as a function of lambda, and points out that these plates, (though) having the qualities of any common plates, they can be sensitized to any wavelength and t can be used for color photography. The present study tried to establish the sensitometric characteristics of Lippmann plates, prepared according the formula of the ingenious inventor of the only direct recording method of color photographs. The results indicated too many variations and lacked the desired consistency. This is certainly due to fluctuations usually occurring (even) with the same composition (differing but on agitation, temperature, filtering, washing etc.). In one case, instead of being sensitive to the wavelength showing the strongest diffraction, we even observed sensitivity to radiation all over the visible spectrum. Without adding any sensitizers, it all the same behaved like an orthochromatic plate and, this was consistent for all plates of that batch, we do not have an explanation. According to Mr. Cotton, who advised us to use colloidal silver, on which grounds he had managed to make plates for interference color photography, we succeeded to get light sensitive layers of very small grains and of great consistency indicated by the measurements we carried out in the case of silver chloride, bromide and iodide.

Preparation of the plates

To a tepid solution (filtered warm) of 2.5 g special gelatin in 50 ml distilled water, 3 ml of a 10% colloidal silver solution are added. The resulting liquid of brown color, is poured on glass plates according to the methods used for collodion. The plates, arranged horizontally until gellation, are subsequently dried protected from dust. These operations are carried out under normal light, thus allowing for the production of a stock to be used occasionally as needed. The transformation of the colloidal silver into halide salts is carried out under subdued light, such as that of a candle or some reduced gaslight. The plate is introduced into a bath for which - after numberless trials - we established the following compositions (note: the quantities given do not correspond with the completed reaction but proofed to work most conveniently for our experiments):

Chloride plates

sodium chloride	2g
copper sulfate	2g
water	1000g

Bromide plates

potassium bromide	2g
copper sulfate	2g
water	1000g

Iodide plates

potassium iodide	2g
copper sulfate	2g
water	1000g

"Bromination" is taking place equally well by using a diluted solution of cupric bromide; cupric chloride however, produced an opaque layer as well as did chlorine water (?) or iodine solution. During the preparation of the iodine (? rather cupric iodide I suppose - MM) bath, a precipitation of cupric iodide is forming which can be eliminated by filtering. As soon as the reaction stops - that is to say, when the yellowish color has vanished - one has to wash the plate, turned transparent meanwhile, exhaustively. At this stage the plates are very little sensitive. A means to this nuisance is to insert them into a second bath of 50g water to which 2g of a silver nitrate solution (0.5g AgNO₃ per 100g water) were added during 1 minute. They are washed with distilled water and dried in darkness. The developer has the following composition:

The plates are fixed in sodium thiosulfate.

Conclusions

Due to the preliminary results, this study represents only some sort of beginning. Nonetheless, we are thinking the constants (?) introduced by Hurter and Driffield into photographic practice, can be applied to the fine grain plates we prepared. We will continue our work, systematically studying the use of chemical sensitizers and try to realize a perfectly orthochromatic "interference" plate. We meanwhile like to point out that the silver bromide plates prepared by flowing, are easily sensitized orthochromatically and allow for spectral recordings of the same brightness as Lippmann plates. The same is also valid for chloride. However, the sensitizers ("orthochromatisants") successfully applied to chloride and bromide, did not show any effect on iodide. Concluding this work, it is an pleasant duty to express my appreciation to professor Cotton (directeur du Laboratoire des Recherches physiques à la Sorbonne), for his support and interest. I equally thank my teacher, Mr. de Watteville, who introduced me into the delicate technique of interference photography... etc. =Making your own plates= by Jeff Blythe Diffusion method - estimated cost by Jean (no login) As promise, I post my estimated costs table for a batch of 20 holoplates made with the Jeff Blyth's diffusion method. Silane, LiBr, Pinacyanol come from Sigma-Aldrich All prices are in Euro (1 Euro ~ 0,97 USD)

Total for 20 plates - - - 21,41 or 1,07/plate (*) I assume I change for each batch : - LiBr + Dye bath - Chrome Alum hardener - Ascorbic Acid sensitizer But please pay attention of this following note from Jeff about the LiBr bath : "please note that I myself reuse the dye/LiBr baths several times. A little bit of precipitate in the bottom of container (it is only AgBr) can be left there and the liquid poured off or the solution just filtered. So you can make many plates if you want to for the initial expence. The quantity of subbed plates you could make is enough for an industrial production run!" I don't calculate price for water, acetone and methanol because those products are cheap. First batch can seems expensive because you need to purchase relatively big quantity in regard of the used quantity and you need to some laboratory material. Hope this can give you the curiosity to test this easy method. Jean PS : my 2nd batch has failed because I don't care to dry plates enough after Chrome Alum bath! Results was presence of chrome salt who fog the plates. I'll try hardening gelatin with a bath of 1% formalin in DI water.

SM-6

• Sodium Hydroxide 12.0g
• Methyl Phenidone 6.0g
• Ascorbic Acid 18g
• Sodium Phosphate (dibasic) 28.4g
• Water to 1L

Stop Bath

• Acetic Acid 20g
• Water to 1L

Safe Ferric Brilland Bleach

(rehalogenating Bleach designed by brilland)

• Ferric III Sulfate 30g
• Citric acid 30g
• Potassium Bromide 30g
• Deionized water to 1000 cc.

You can use it and store it for a very long time at room temperature. It gives very low noise results.

AAC

• Ascorbic Acid 18g
• Sodium Carbonate to give a pH of 10.5
• Distilled Water 1L

AGFA 80

• Metol 2.5g
• Soduim Sulfite (anhydrous) 100g
• Hydroquinone 10g
• Potassium Carbonate 60g
• Potassium Bromide 4g
• Distilled Water 1L

GP-8

• Metylphenidone .2g
• Hydroquinone 5g
• Sodium sulfite (anhydrous) 100g
• Potassium hydroxide 10.6g
• Ammonium thiocyanate 24g
• Distilled water 1L

Mix 60 ml of developer with 400ml of distilled water. Develop for 6 minutes at 20C.

GP-2

• Metylphenidone .2g
• Hydroquinone 5g
• Sodium sulfite (anhydrous) 100g
• Potassium hydroxide 5g
• Ammonium thiocyanate 12g
• Distilled water 1L

Mix 15ml of developer with 400ml distilled water. Develop for 12 minutes at 20C without agitation. Develop with plate facing up and DO NOT agitate (you don't want to move the disolved silver away from the plate).

CPA1

• Metylphenidone .02g
• Hydroquinone .65g
• Sodium sulfite (anhydrous) 13g
• Potassium hydroxide 1.4g
• Ammonium thiocyanate 3.1g
• Distilled water 1L

Develop for 2 minutes at 22C. 3 seconds of initial agitation.

N6

• Metol .5g
• Sodium Sulfite (anhydrous) 100g
• Hydroquinone 45g
• Sodium carbonate 30g
• Potassium thiocyanate 5g
• Potassium bromide 10g
• Distilled water 1L

Mix 1 part developer to 8 parts distilled water.

F1

• Amidol 4g
• Sodium sulfite (anhydrous) 30g
• Silver nitrate 3g
• Potassium bromide 2g
• Sodium thiosulfate 45g
• Distilled water 1L

Develop for 8 minutes. Fix for 2 to 3 minutes.

F2

• Metol 10g
• Sodium sulfite (anhydrous) 100g
• Silver nitrate 2g
• Potassium bromide 2g
• Sodium thiosulfate 30g
• Distilled water 1L

Develop for 30 minutes. No fix is required.

MM-Collo 1

From Martin: The best formula I ever made for a colloidal developer was:

• Metol.............................2g
• Ascorbic acid.....................7g
• Methylphenidone.................0,5g
• Potassium bromide.................3g
• Potassium carbonate..............20g
• Ammonium thiocyanate..............2g
• Distilled water...................1L

Dilute 1 : 50 or up to 1:100 (with distilled water) On PFG-03M it yielded extremely fine grains, resulting in a yellow emulsion (compared with the orange/red layer produced upon GP development). Development is quite slow, requiring > 30 min @ 20°C.

VR-P developer

• Sodium Sulphite anhydrous 194 g
• Hydroquinon 25 g
• Potassium Hydroxide 22 g
• Methylphenydone 1.5 g
• Potassium Bromide 20 g
• Potassium Metaborate 140 g *1,2,3-Benzotriazole 0.1 g
• Distilled water to 1 L

Working solution: 1 part of VR-P Developer + 6 parts distilled water

Phillips' Ferric Nitrate Bleach

• 150 g Ferric Nitrate
• 33 g Potassium Bromide
• 20 g Glycerol
• 300 mg Phenosafranine
• 500 ml Isopropyl
• 500 ml Distilled Water

Phillips' PBQ-1 Bleach

• 2 g PBQ
• 30 g Potassium Bromide
• 1.5 g Boric Acid
• 1L Distilled Water

Phillips' Ferric EDTA

• 30 g Ferric Sulfate
• 30 g Di-sodium EDTA
• 30 g Potassium Bromide
• 10ml Sulfuric Acid
• 1L Distilled water

D-14H

From Hans: I got this formula from http://silvergrain.com/labs/Print_Developer_Recommendation?title=Print_Developer_Recommendation It does not to be mixed in a A and B solution and I have found that it works just as good as the Ultimate safe holographic developer. I made on adjustment to the original formula in that I left the KBr out because I don't think that there should be KBr in a holographic developer. Development time is about 1.5 minutes.

• Dimezone S 0.2g
• ascorbic acid 6.0g
• sodium sulfite, anhydrous 12.0g
• sodium carbonate, monohydrate 30.0g
• triethanolamine, 99% 5.0ml
• salicylic acid 0.5g
• water to make 1.0 liter target pH 10.4 ± 0.2

Ascorbate Developer

But I contend that the best way of dealing with ascorbate developer stock and it is a way we have been successfully using for some years in our labs is to "A and B" it.

For A we have a 500ml bottle with:

• 20g ascorbic acid
• 3g Metol (4-methylaminophenol sulfate)
• and top it up with 500ml deionized water

for B we have a 500 ml bottle of

• 50g sodium carbonate anhydrous
• 15g sodium hydroxide top up with 500 ml deionized water.

(This one should be labeled "very caustic") Just use equal volumes of A and B from then on. Now there are 3 bonus points for using Metol instead of phenidone. 1) is that phenidone is quite a strong silver halide solvent and tests have proved that metol gives brighter holograms. 2)The second point is that metol has a hardening action on gelatin and its effect on speeding up the development time over what you would have with just alkaline ascorbate means that even notoriously soft emulsions juch as PFG-03 can be in and out of the developer bath into a stop bath (~5% acetic acid ) in around 20 seconds, before the gelatin is seriously attacked. Assuming of course your exposure level was good enough. 3) Metol is a weaker reducing agent or developer than alkaline ascorbic acid. When Metol gets oxidized it goes really dark brown so this is a useful indicator to tell you when your bath is exhausted because it wont go severely dark until most of the ascorbate has been oxidized. A mild yellowing like weak tea is quite OK . Dont forget to use the floating dish method of 2 closely fitting plastic dishes with the upper dish keeping most of the air out as it floats and acting as convenient agitator as well. Acid ascorbate in the stock soln A will not seriously oxidize for a year. (Slight yellowing is perfectly OK . ) jeff

Metol-Ascorbate developer courtesy of Laser Reflections

The formula is as follows: Metol-Acorbate Developer (Part A + Part B)

Part A:

• Metol 10g
• Ascorbic Acid 80g
• Water to 1000ml

Part B:

• Sodium Carbonate Anhydrous 120g
• Sodium Hydroxide 14g
• Potassium Bromide 4g
• Water to 1000ml

Use it in combination with a Fe-EDTA bleach - a safe, stable bleach which has a long shelf life.

Fe-EDTA Bleach

• EDTA (2Na) 30g
• Fe(III) Sulfate 30g
• Potassium Bromide 30g
• Sodium Hydrogen Sulfate Crystals 30g
• Water to 1000ml

Sergey Vorobyov's developer - OD-1

New postby Gall » Mon Nov 08, 2010 12:05 pm Some time ago Mr. Vorobyov invented a developer for silver-halide holograms that does not contain any rhodanides. It is ideal for both beginning and advanced holography. The original Russian article is here: http://www.holography.ru/tech8rus.htm Original formula:

• Metol = 2 g
• Sodium Sulphite (anhydrous) = 25 g
• Hydroquinone = 5 g
• Borax B[sub]4[/sub]H[sub]4[/sub]Na[sub]2[/sub]O[sub]7[/sub] = 2 g
• Sodium Thiosulfate (photographic fixer) = 6 g
• Water = 1000 ml

Here sodium thiosulfate replaces rhodanide. It dissolves AgBr so that the process is the physical one and not the chemical one.

Simplified formula - made from Kodak D-76, ideal for beginners (image is slightly worse but still works):

• Take Metol and Hydroquinone mix from two ready-made 0.5l D-76 packages (2x[1 g + 2.5 g]).
• Take Sodium Sulphite and Borax mix from one package (1x[50 g + 1 g]).
• Add 6 g (one teaspoon) neutral fixer (Sodium Thiosulfate).

This will result in following:

• Metol = 2 g
• Sodium Sulphite (anhydrous) = 50 g
• Hydroquinone = 5 g *Borax B[sub]4[/sub]H[sub]4[/sub]Na[sub]2[/sub]O[sub]7[/sub] = 1 g
• Sodium Thiosulfate (photographic fixer) = 6 g
• Water = 1000 ml

Dissolve Metol and Hydroquinone first in some warm (40-45 centigrades) water, then add everything else, add water to 1000 ml and filter the solution. The resultiong solution should be mixed with water 1:4 before use. Develop around 10 minutes at 18 centigrades.

Zip1

For transmission Holograms. I have been using my own developer for the last three years which is extremely active requiring much shorter exposure times than others (JD-2, JD-4, Pyro, etc). Used it for reflection and transmission on Slavich (especially VPR-M) and Agfa films and plates (8E75/56). Sometimes EDTA and sometimes Dichromates bleaches:

Zip1:

• Metol 1gr,
• Hydroquinone 1gr,
• Phenidone 0.5gr,
• Sodium Sulphite 30gr,
• Ascorbic Acid 10gr,
• Potassium Hydroxide 30gr,
• water to make 1 litre

Dave I've used it for reflections in place of the pyro developer and with the dichromate bleach. It also over comes the hassle of accidently getting stained fingers with the pyro developer if you forget to put the rubber gloves on. The main benefit I've found is that the image brightness is on a par with the other developers with the bonus of shorter exposures. The mix of the Metol, Hydroquinone and Phenidone with the Potassium Hydroxide is quite an active combo. I'm not really surprised and certainly these chemicals are cheaper than pyro and catechol.