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  1. #1

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    Finally, the Edwal Super 20 actual production formula.

    Hi Everybody,

    First a little background with a post I put up on Photo Net in 2003. It was as follows:

    Through the mid 60s to the 80s I used Edwal Super 20 exclusivly after trying virtually every developer then available, becase it gave an unequaled combination of very fine grain, high sharpness and (most of all) super compensation for the usually over-contrasty outdoor shots taken in the harsh Florida sun. I had originally become a fan of it because I had supplemented my TA stipend in graduate school by doing affordable 35mm portraiture and found it gave beautiful grain and tonality in that application.
    I am ready to do whatever it takes to duplicate the formula. Bud, the owner of the Photographers Formulary has talked to Bill Troop, co-author of the Film Developing Cookbook about the formula given there on page 67 and Mr. Troop has said that it is NOT, in fact, the correct one. The Film Developing Cookbook mentions in a note regarding the formula given that "incorrect" formulas have been published elsewhere. The Photographers Formulary suggested that if I could obtain one or more of these it (in conjunction with the Troop formula) it would give me a starting point to experiment with to try to home in on a working formula.
    If Super 20 can be duplicated , Bud would consider making it available to the B&W enthusiast community. I don't know how many of you have used Super 20 in the past, but rediscovering the formula would be a great service to the B&W community. It is a staining developer with many Pyro-like qualities, but with much finer grain, better acutance and much better compensating characteristics. If you can give me any leads I will be dilligent in following up and getting you the results of my attempts to replicate the formula. I have thousands of Super 20 negatives so I know exactly what results I am looking for! Thanks! Jay Ludvigh

    There was a good bit of discussion and speculation at that time, but nothing definitive regarding the exact formula. After conversations with Bill Troop and a bit of detective work I was able to track down Bob Schrader who was the production line supervisor for Edwal during the last years Super 20 was in production. He agreed to give me the formula, but asked that I not disclose it because he thought he might someday want to market it. I mixed it up using the facilities of the chemistry lab at the university where I'm adjunct faculty, because it is hard to get into solution an requires a heated magnetic stirer to get the job done. I compared it to my original negatives and while there were some differences because of the changes in more modern films it was clearly the same developer. I also was able to get an unopened, well stored bottle of Super 20 and compared it to my brewed version with modern films and found the results identical. So, what we have here is the real thing.

    The problem is that it is a pain to brew and I no longer have access to the chem lab due to a change in personel. I have been thinking that with the actual formula and expert input from savy APUG members, a more user friendly home brew method could be found. I have tried to contact Bob Schrader but have been unable to do so and since it has been over 9 years since he asked me to keep the formula to myself and nothing has happened in terms of him producing it I decided to make this post.

    Here is the exact formula which he provided me. According to the chemist who helped me make the first batch it has "archaic" chemical terms and units of measure, but here it is:

    To make 1 ltr

    1) Hot water 120-130F (distilled preferred) approx 28 oz.
    2) ParaAmino Phenol 2.62 gm
    3) Sulfuric Acid 66 degree baume .2154ml
    4) Sodium Sulfite 89.95gm
    5)Para Phenylene Diamine 9.59gm
    6) Glycin 4.797gm
    7) Water to 1ltr

    Desired ph-7.6
    Adjust with caustic soda/28% acetic acid
    do not add second chemical until first is dissolved

    The above is the word for word info he sent me on how to make Super 20. I sent him a heartfelt e mail of thanks and have not heard from him since. I deeply hope he is not still out there planning to go into production himself and am only posting this now to benifit other "film dinosaurs" like myself.

    If anyone with photochemistry expertiese out there can use the formula to figure out what Gradol was or how to brew Super 20 without having to use the sulfuric acid and ph adjustment process this could become a developer that a lot of people could use.

    Jay Ludvigh

  2. #2

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    According to my notes Gradol was paraminophenol hemisulfate rather than the more common hydrochloride salt. To adjust the pH without using sulfuric acid I would substitute paraminophenol hydrochloride for the free base. This salt is easier to obtain and has better storage properties.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  3. #3

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    Sounds interesting. Is this a one-shot developer used at full strength or with some dilution?

    Steve

  4. #4

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    It can be used diluted 1-7 or used straight with replenishment by discarding 3oz of developer after processing each 36 exposure roll and adding 3 oz. of fresh Super 20. I used the replenishment method for the most part.

  5. #5

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    Developers like Edwal Super 20 fell out of favor with the advent of newer finer grained emulsions. Paraphenylenediamine is a slow acting developer and a silver halide solvent. Its action in Edwal Super 20 is primarily that of a halide solvent. When used alone this developing agent results in a severe loss of film speed which explains the presence of Gradol to partially counteract this loss.

    There are two downsides to the use of phenylenediamine. First, modern emulsions may not react favorably toward it. Second, it can cause severe allergic dermatitis and is a known cross sensitizer. Which means that you may also develop a sensitivity to Metol and the color developing agents. If you insist on using it wear a dust mask when handling the solid and protective clothing and nitrile gloves when handling it or its solutions. I can attest to the fact that it is nasty stuff.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  6. #6

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    Gradol

    I went through about the same process with this at about the same time. Without my notes in front of me, it looks like your formulation is missing the chemical called Gradol to disguise it. I have notes on that and remember that it might not be easily available in the original form but there was at least one substitute that was. I remember jumping for joy when I saw Super 20 in the "Cookbook". When I mixed it up I got a severe precipitate. Mr. Shrader found that the "Cookbook" formula was adding Glycin and then going through a Glycin synthesis I believe in part 2 without looking. So Glycin was precipitating out of soulution. I made the stuff without Gradol and used it with Acros 100 with success but the speed was way to low. My past experience with Super 20 was with Panatomic X which processed at about 50% of the manufacturer's ASA rating which is normal for most film-developer combinations. I haven't mixed up new stuff with the Gradol substitute yet but am interested in any experience people are having with Super 20.

    Compounding this formulation isn't that bad considering it lasts so long. I keep some for one-shot and also use it replenished and it last for years. There is a stain remover that is easy to make.

    Ernst

  7. #7

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    Quote Originally Posted by ernst1 View Post
    it looks like your formulation is missing the chemical called Gradol to disguise it.

    Mr. Shrader found that the "Cookbook" formula was adding Glycin and then going through a Glycin synthesis I believe in part 2 without looking.
    Gradol is the hemisulfate of paraminophenol. The developing agent is paraminophenol, it really doesn't matter what particular salt is used.

    "adding Glycin and then going through a Glycin synthesis " ??? this makes no sense to me.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  8. #8

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    Thanks for the input so far,

    Using the exact formula and mixing proceedure provided me by Bob Schrader it is possible to come up with a developer which appears, in all respects, to be Super 20. It does, however, require continuous stirring at an elevated temperature using a magnetic heater-stirrer in order to get the components into solution. I'm wondering if anyone has any idea of how to simplify the process and/or can provide more commonly used descriptive terms and units of measure so I can get back to mixing some up.
    BTW, I did not notice a significant reduction in film speed, perhaps half a stop at most. Super 20 was espically nice with Tri-X giving Plus X grain, gorgeous tones and (for me) full film speed. I'm thinking it might be great with some of the more " old style" emulsions like Kentmere 400 or Foma 200. If I can figure out how to upload them, when I get bgack from out of town in October, I will scan a couple of my 35MM Tri-X portraits developed in Super 20 from the 60s as well as some from 2005 using the Schrader formulation.

    Jay

  9. #9

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    I've used both Dupont 5-D and Windisch W-665 with Tri-X getting excellent results with maybe a half stop speed loss and good sharpness. Both these developers use a second developing agent (glycin in 5-D. metol in W-665) to counter the annoying characteristics of PPD. Although they were a disaster 20 years ago, PPD developers seem to work with today's films.



 

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