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  1. #21

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    Sandy,

    My current conclusions are that the differences in negative apparent sharpness is very clear BUT DEPENDS on the film being used. I see more differences in apparent sharpness using Efke PL100 than Fortepan 200 for example.

    You are right that it really depends on the type of scene being shot. I find that my negatives of high key scenes (where EVs are in the double digits, e.g. EV range 11-14 or 14-17 etc., as opposed to EV ranges 7-10 or 5-8) are better suited for minimal agitation. It is when printing these negatives that the apparent sharpness comes across on paper as well (and yes it is the micro contrast that kicks a#*¤ - recall that scene I posted with the bark detail and fallen branch in snow). Yes, your conclusion matches what I have observed about subjects with a lot of adjacent highlight and shadow areas. They print better.

    The question about whether it is worth the trouble (more time, more solution) is hard to determine right now. The best advise I can give myself is to choose wisely which negatives should be given the minimal agitation treatment and even prior to that making the correct film choice for the particular scene being recorded. I believe that there was an article in the Unblinking Eye concerning film choices based on scene contrast. It certainly applies here.

    Despite some disappointing prints, I am still continuing with the experiment and in fact I have been making slight modifications to the agitation procedures. At the very least I am learning more about the films I use and how they react to Pyrocat HD. So I guess it is worth it after all!

    Francesco

  2. #22
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    My rollo Pyro kit got in tonight! I'll be reading Gordon's book along with repairing my leaky unicolor drums tonight. If Mother nature cooperates with me, I'll be out shooting 4x5 and 8x10 test shots tomorrow. 4 sheets per scene. 1) Rollo Pyro, 1) D76 1:1, 1) D76 1:0, and one safety in case something goes wrong. I'll post my results.

    Brian
    hi!

  3. #23

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    Sandy King[/quote]
    I am curious to know exactly what you found to be too much work about the use of ABC and PMK.

    My first 8x10 negs were plagued by blotches, streaks and irregular development. I solved these (for the most part) with long pre-soaks in alkalinized distilled water and by cutting down the batch development to no more than 4 negs in a tray. Development times were usually 18 minutes with PMK, and I had to wear gloves.

    With HC110, a short presoak in filtered water; batches of 8; and 7 minute development times without gloves makes my life easier. Face it, developing film is just not the best part of ULF photography.

  4. #24
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    Just a general note about poisonous stuff. Have you read the fine print on the bottle of HC110 concentrate? Makes you wonder if pyro is so bad after all.
    Gadget Gainer

  5. #25

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    Quote Originally Posted by Deckled Edge
    Sandy King
    I am curious to know exactly what you found to be too much work about the use of ABC and PMK.

    "My first 8x10 negs were plagued by blotches, streaks and irregular development. I solved these (for the most part) with long pre-soaks in alkalinized distilled water and by cutting down the batch development to no more than 4 negs in a tray. Development times were usually 18 minutes with PMK, and I had to wear gloves.

    With HC110, a short presoak in filtered water; batches of 8; and 7 minute development times without gloves makes my life easier. Face it, developing film is just not the best part of ULF photography."

    I never got any streaks and such with PMK and tray development, but I did with rotary processing, which is one of the main reasons I developed the Pyrocat-HD formula. On the other hand PMK is definitely not an ideal developer for those printing with the alternative processes because of the very long develoment times required to get enough contrast. Rollo Pyro and Pyrocat-HD, on the other hand, are much more energetic and develoment times with these developers are less than half of PMK for a given CI.

    BTW, you might want to think again about not using gloves with HC-110. I believe it contains hydroquinon and other reducers which are only slightly less toxic than pyrogallol.

  6. #26

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    So far, so good! I've been dunking my hands in HC110 and TMax RS for 6 years without allergic reactions or rashes. My understanding is that while hydroquinone is sensitizing, and can cause serious health consequences to some people, pyrogallol is toxic, and enough exposure causes health consequences to all people. The warning on the HC110 bottle (and any package containing hydroquinone) warns of possible skin reaction. On the other hand everyone who writes about PMK notes that pyrogallic acid is "nasty stuff" and warns about the powder, as well as direct contact with the developer solution.
    That said, all the neat stuff in our darkrooms is potentially lethal, if not to us, then to our environment, and should be handled in a responsible manner. We really can't be too careful.
    ..but I'd hate to go back to gloves! ;-(

  7. #27
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    This from the British Pharmacuetical codex (recent)

    Action and Uses.—Pyrogallic acid is a powerful antiseptic by reason of its affinity for oxygen. Taken internally it exerts a toxic action on the blood, methaemoglobin is formed, passes into the plasma, and leaves the red corpuscles as granular debris; jaundice and acute nephritis may follow, hence the drug is now very rarely given internally. It is used as an antiseptic and mildly irritant ointment in chronic skin diseases such as psoriasis, also to destroy lupus; it is of value as a parasiticide in ringworm. Mixed with four times its weight of starch, the acid is applied as a powder to phagedaenic chancres. It has the disadvantage of staining the skin and hair black, and must be used with caution on account of the danger of absorption. Stains upon the skin may be removed with ammonium persulphate. Pyrogallic acid is an ingredient of hair dyes, usually with silver nitrate; and is largely used as a reducing agent in photography.
    Non Digital Diva

  8. #28

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    Fortunately some of us use tubes for developing sheet film and there is no need to touch the stuff or for that matter work in the dark, hence avoiding any mishaps due to reduced vision. Better safe than sorry. In addition, buying Pyrocat in a liquid form kit, such as that available from Lotus View (I believe they are the only ones that provide this kind of service) , further reduces any chances of whatever miniscule, tiny, microscopic risk there might be of playing around with powdered chemicals.

  9. #29

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    Quote Originally Posted by Deckled Edge
    So far, so good! I've been dunking my hands in HC110 and TMax RS for 6 years without allergic reactions or rashes. My understanding is that while hydroquinone is sensitizing, and can cause serious health consequences to some people, pyrogallol is toxic, and enough exposure causes health consequences to all people.
    The MSDS safety sheet list hydroquinone as a toxic agent. To quote,

    "Probable carcinogen. Toxic. Severe skin irritant. Harmful by inhalation and ingestion. May cause sensitization. Eye and respiratory irritant."

    The MSDS sheets indicate that pyrogallol is more of a risk, but the difference is not as great a s some people believe. Chemically the two agents are very similar. People do appear to be more aware of the risk of pyrogallol and pyrocatechin than other reducers, which may be due to the fact that the people who promote developers based on these agents have taken a responsible position and warned of the health risks.

    Bear in mind that sensitization to a chemical normally results from long-time use, and once you become sensitized it is for life. I worked for many years on a boat-building project with epoxy and would frequently get it on my hands. I had no problems at all for years and years, but one day after some got on my hands I developed a severe rash, with many visible bumps, on my forehead and fingers. Every since then any contact with epoxy, or sometimes just the smell alone, causes eruptions of the same type and in the same place. I think anyone dunking their hands in developers that contain reducers such as hydroquinone and metol run the same risk of sensitization.

    People who insist in not using gloves with tray development should consider switching to one of Patrick Gainer's Vitamin C formulas. My understanding is that ascorbic acid is about as safe a reducer as you can find.

    Sandy

  10. #30

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    BTW, I just got word from Dick Sullivan that Bostick and Sullivan will soon begin marketing Pyrocat-HD in a liquid kit. I am confident that B&S will produce a quality product that is fully consistent with my own standards for this developer. And as anyone who has dealt with B&S knows, they are great at providing support for their products.

    Sandy King

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