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Thread: Pyro Stain bane

  1. #11

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    The ABC formula is in "the Negative", by Ansel Adams and you can find it on the web. If I recall correctly, it is basically pyro, sulfite, bisulfite, carbonate, and a small amount of bromide. I suggested ABC purely to help compensate for the extra 2 stops of exposure you gave the negatives. Using the ABC formula should kill about 1 stop of film speed. You'll have to decide what formula to use in the long run. I can't comment on Pyrocat-HD. I have no experience with it and haven't had the need to try it. I'm happy with my modified Wimberley formula and "if it ain't broke, I have no reason to fix it".

    Bob Herbst

    Quote Originally Posted by Jarvman View Post
    Thanks Bob! I was actually reading your appendix in Dick Arentz book last night. I understand now that if I want to increase the contrast of my negs I should increase film speed because the shadows are receiving extra development too. Do you think I will get away with using Pyrocat rather than ABC as I have none of the latter? Perhaps developing for normal time rather than N+1. The other option was to develop them in D-76. I can't get ABC premixed in the UK. Suppose I could mix my own, there's a formula in the Darkroom Cookbook aint there.

  2. #12

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    Controlling stain with PMK means controlling oxidation. You'll know you're doing it right when the developer comes out looking the same as it did going in. The trick is filling the tank all the way (you can do this with the jobo if you roll it by hand) or using nitrogen gas - commonly available at welding supply houses. My base + fog on PMK negs is no more than what I get when using rodinal or d76. What's your process like?

  3. #13

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    Sheet film in trays, not much chance of controlling oxidation!

  4. #14

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    Owie! No wonder you're getting bad results! In sheet sizes 4x5 I use a combi-plan. It works really well if filled all the way up. I increase my agitation cycle to once every 10" to make up for the diminished surge during inversion.

    In 5x7 I used to use a jobo drum filled all the way to the top, then corked and hand rolled in the jobo trough. Then I graduated to nitrogen gas. More recently I discovered a 5x7 combi-plan which makes it simple once again.

    I screwed up more negatives with PMK before nailing my technique down. In the process I've tried out all the other pyro formulas from Rollo to ABC to WD2d and I still find a clean PMK negative to be my favorite.

  5. #15

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    Hmm, I think it might be worth investigating drums if I'm using pyro formulas then. I'm going to try a neg in pyrocat tonight and see if that works out ok, either way I'll buy the raw chemicals for ABC tomorrow and try that solution out. Phew.

  6. #16

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    Keep in mind that with the Jobo you need to insert the sheets into the tank already wet, at least with PMK. I can't remember where I picked up this tip and I know it sounds crazy but it's the only way I found to get consistent stain all the way across the negative. Fill the drum all the way with water, insert the film in the dark. Kind of a PITA which is why I prefer the combi-plan. Also, with the jobo considerable amounts of PMK are needed to displace the volume of the tank. This is not an issue if a proper nitrogen gas technique is employed.

  7. #17

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    Quote Originally Posted by Jarvman View Post
    Hmm, I think it might be worth investigating drums if I'm using pyro formulas then. I'm going to try a neg in pyrocat tonight and see if that works out ok, either way I'll buy the raw chemicals for ABC tomorrow and try that solution out. Phew.
    Have a look at my article on staining developers at http://unblinkingeye.com/Articles/PCat/pcat.html You will find a history of pyro developers and some specific information about a few staining developers. The article was written some years back and there have been some new developers introduced since then, and some modifications to existing ones, but the basic information in the article is still sound.

    I developed the Pyrocat-HD formula in 1997-98 to overcome the problems of the existing pyro staining developers in rotary development systems, such as Jobo, BTZS tubes and in drums. The stain of Pyrocat-HD (and Pyrocat-MC) is almost neutral in color, and B+F (or general stain) is very low without modification of the developer, which is necessary with some pyrogallol based formulas when developing with continuous agitation. The reducing agent in Pyrocat-HD (and -MC) is pyrocatechin (or catechol or pyrocatechol) which is much more resistant to stain from oxidation than pyrogallol. It is possible to modify pyrogallol formulas by adding more sulfite or ascorbic acid to control general stain, and this has already been done in the case of Rollo Pyro.

    ABC Pyro is a very old formula and I definitely would not recommend it for rotary processing, or for that matter for any negatives that are to be enlarged since it tends to give very large grain.

    All things considered you might also try developing the remaining negatives that are two stops over-exposed with a non-staining developer like D76 1:1. You will still have more shadow detail than needed but you will have a much lower B+F with over-exposed negatives with a non-staining developer than with a staining one, and this will translate into much shorter exposure times with UV processes.

    Sandy King
    Last edited by sanking; 03-24-2010 at 02:08 AM. Click to view previous post history.

  8. #18
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    Quote Originally Posted by frotog View Post
    Keep in mind that with the Jobo you need to insert the sheets into the tank already wet, at least with PMK. I can't remember where I picked up this tip and I know it sounds crazy but it's the only way I found to get consistent stain all the way across the negative. Fill the drum all the way with water, insert the film in the dark. Kind of a PITA which is why I prefer the combi-plan. Also, with the jobo considerable amounts of PMK are needed to displace the volume of the tank. This is not an issue if a proper nitrogen gas technique is employed.
    I have never read anything like the post quoted above anywhere. I develop with Jobo tanks and have no darkroom (I use a Harrison tent). I do a pre-wash of my film before adding my Pyrocat-HD to the tank.
    Diane

    Halak 41

  9. #19

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    Quote Originally Posted by colrehogan View Post
    I have never read anything like the post quoted above anywhere. I develop with Jobo tanks and have no darkroom (I use a Harrison tent). I do a pre-wash of my film before adding my Pyrocat-HD to the tank.
    That's cool...just passing on what works for me. Keep in mind that I'm passing on technique for PMK per the OP's original query (did you read it?). BTW...sorry to hear about the drkrm.!

  10. #20

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    Quote Originally Posted by colrehogan View Post
    I have never read anything like the post quoted above anywhere. I develop with Jobo tanks and have no darkroom (I use a Harrison tent). I do a pre-wash of my film before adding my Pyrocat-HD to the tank.
    Diane,

    With some tubes and drums the film fits so tightly that if you load the film dry and then pre-soak and develop the the solutions will not fully reach the back (or base) of the film during processing because it is so tightly pressed against the inside of the tube/drum. If this happens it may be very difficult to remove the film after you finish processing. I have this very problem when developing 5X7" film in home made ABS plastic tubes so I always wet the film first, then insert it in the tube.

    With other tubes and drums where the film has a looser fit in the tube/drum (or where there are ribs or chananels ) I do not find it necessary to pre-wet the film before loading it because the solutions will wet out the entire back of the film during processing.

    Sandy King

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