PMK: how much developer for a 35mm film? : LUSENET : B&W Photo - Film & Processing : One Thread

I posted a question a couple of weeks ago about the fairly subtle amount of stain in my HP5+ developed in PMK standard concentration. I had expected more. I decided to try using a generous amount of developer, and I noticed that when I developed a single film in 1 Litre of PMK, the developer after use was not as coloured as usual, and I got less stain. Then I tried one film in 500mL and got more colour in the used developer and more stain.

Then I remember reading somewhere that the oxidation of PMK was mainly caused by development, not contact with air. So if the desirable stain in the film is caused by oxidised developer, then using less volume should give more stain. So next I used 250mL for one film and the developer came out darker than before. The image stain was about the same as for the 500mL test. I read in Anchell + Troop that 500mL is necessary to be sure that you're getting the full benefit of the developer. This is different advice to that given in Gordon Hutchings's book. I was curious whether my 250mL was exhausted at the end of the first roll, so I used the used developer to develop another roll of HP5+. I gave it 20 minutes instead of 12 to give it a chance but the film came out absolutely blank. So maybe 250mL of PMK is *totally* used up in doing one film. I suppose it means that development time over my 12 min (20c) would not give any significant further development (not that my vigorous negatives needed any more- actually they could have done with a fraction less). I exposed some zone_1 frames on the film and it shows an EI of 160 or 200 (Nikon F100 meter, which is probably my most accurate meter, and most accurate shutter speeds). Next test: will 500mL give me a higher EI?

The only thing I'm doing differently to most other people is that I'm using Agfa FX-Universal alkaline fixer because in Australia TF-4 is not available. It smells slightly of ammonia, fixes fast, and is fairly cheap. It is used primarily for colour processing, but several people have recommended it for B+W. I don't suppose it might have something in it which would reduce the PMK stain, would it?

-- john stockdale (, June 27, 2001



I don't know what effect Agfa FX will have, but since it's an alkaline fixer, should work OK. For increased stain on the negatives, you might want to try placing the fixed film back into the used developer for 2 minutes, then giving it a very thorough wash (minimum 20 minutes.)


-- Pete Caluori (, June 27, 2001.

John, I wonder two things: When you are using different volumes of developer (250, 500 and 1000ml), are you using the appropriate volume of PMK stock, or are you using a set amount and using more or less water, thereby varying the dilution ratio? Two, when you are developing one roll in 250, 500 and 1000ml, are you filling an appropriate sized tank, or are you developing, for example, one roll in 250ml of developer in a 1000ml tank?

Assuming you are using a consistent dilution ratio and you are completely filling your developing tank, the only other things I can think to check are your water pH, and as previously posted, your redevelopment procedure and wash duration. If you are not using distilled water for developing, I recommend you try a roll with distilled water. It's possible that your water is slightly acidic, thereby neutralizing the alkalinity of your developer, which will limit staining.

-- ted kaufman (, June 27, 2001.

John, I have used home made pmk pyro of some time, and I find the best stain comes with old technology films; FP4+ and HP5+, the latter having much more stain. Two things seem to increase the stain, one, the amount of air in the tank (therefore more oxidation) try processing a single film in a large tank with only enough developer to cover the film. Two, long washing in colder water (here in England the water runs at about 16 degrees even in summer), this helps the harding action the staining. Yours Jeff

-- jeff teasdale (, June 27, 2001.

Thanks for you quick responses. There's a lot of interest in PMK! To clarify a couple of points, I used PMK in the correct dilution for all tests (100:1:2), I did the resoak in used developer, and long cold water wash. No, I used tap water. Here in melbourne, Australia the water is quite low in mineral content and has a little chlorine. In the three tests, there was not much air. Would you expect much difference with a larger tank and more air?

-- john stockdale (, June 27, 2001.

To increase stain, Hutchings recommends mixing PMK an hour or so before use. The color of the developer gets darker as it sits, which I presume is oxidation. I've had a little luck with that trick. And I think I'll try the bigger tank idea. 250ml of developer with one 36 exposure 35mm film seems to work just fine at my house.

To increase speed with HP5, Hutchings recommends double-strength PMK. I think I've gained maybe half a stop that way. It also seems to help P3200.

The only way I think of that the Agfa fixer might be hurting stain is if it is high in sulfite. A lot of commercial preparations are. And you are NOT using an acid stop bath, right? (Only water.)

-- Brian Hinther (, June 27, 2001.

yes, just water for the stop bath

-- john stockdale (, June 28, 2001.

John, If you develope your film with a large tank, filling it partially, you will run the risk of underdevelopment. Such treatment will oxidize the developer much more rapidly, which may increase staining, but will also significantly diminish developer activity. It will also make it difficult to achieve consistency. For example, how would you determine a time if you develop two rolls in a 1 liter tank (using 500ml of solution) if you established a time for one roll in the same tank using 250ml? This problem, specifically, is why Rollo Pyro was developed. In tubes or Jobo-type roller processing, the developer oxidizes too quickly, causing underdevelopment. Hutchings suggests adding 30% more "A" solution to counteract the oxidation. Rollo pyro adds vit-C and much more pyrogallo to solution A. Rollo Pyro is another option you can try, but I think you can anticipate considerably more grain with 35mm film.

Personally, if you aren't getting adequate stain, I'd try the suggestion of letting the developer sit for an hour before use, or try Hutchings' suggestion of increasing the A concentration.

As for capacity, Hutchings states that 250ml is adequate for one roll of 35mm. Anchell/Troop were speaking in general terms about all highly dilute developers. I think 250ml is adequate with PMK, but, with that said, I always fill a 500ml tank for one roll and 1000ml for 2 or 3 rolls.

If all else fails, you can mix up a solution of sodium carbonate, using a tablespoon or two (precision is not important with this) in one liter of water. Then, instead of redeveloping in the used developer, treat the film in the carbonate solution as you would with used developer. This will increase stain considerably. However, it will not be as descriminating as used developer--it will add stain to the entire film, not just the image area. This works quite well with films like TMX that resist staining.

I can't understand why you're not getting adequate stain with HP5+. Fast films stain better than slow, and HP5+ should stain very well. Why don't you try mixing up a batch of TF-3 fixer (Film Developing Cookbook/Anchell&Troop--if you don't have this book, get it; you'll love it!) ammonium thiosulfate (57-60%) 800ml, 60g sodium sulfite, 5g sodium metaborate, plus water to make 1000ml. Working dilution is 1:4 with water. I recommend distilled water. You can also use TF-2: 750ml water, 250g sodium thiosulfate, 15g sodium sulfite anhydros, 10g sodium metaborate, water to make 1000ml. Use undiluted. I prefer the TF-3, but TF-2 will at least give you a basis for comparison with your Agfa fixer. Good luck!

-- Ted Kaufman (, June 28, 2001.

Thanks Ted and all other contributors!

I've not been able to source ammonium thiosulphate here in Australia yet. I notice that the formula for TF-2 contains sulfite. Is the concentration of that (15g /Litre) high enough to interfere with the stain? Would I be better off to use a plain hypo fixing bath? I don't mind if it's one-shot or won't keep.

-- john stockdale (, June 28, 2001.

John, Plain hypo is probably the simplest solution. The TF-2 formula I gave is from Anchell/Troop book, and they say it is suitable for tanning developers. But just to see if your stain improves with a different fixer, give hypo a try. Incidentally, when I first tried PMK, I didn't have an alkaline fixer, so I used Kodak Rapid Fix w/o hardener and the film stained pretty well.

-- Ted Kaufman (, June 28, 2001.

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