Tom Hoskinson said:Brad, I agree with Lee, your problem sounds like "air bells." Pyrocat is my developer of choice for most applications. I aways use a water presoak with pyrocat and gentle torus inversion agitation (with a small tank) (or continuous rotational agitation - with BTZS type Tubes). I never see the problems you described.
erikg said:Having said that, I think Sandy may on to something with the pinhole theory. For one thing, these specks have sharp edges, and air bells that I have seen have been both bigger, and have had softer edges.
I have test film that I will run tonight. Any suggestions as to what I should try? Acid stop bath-- no stop bath? semi-stand?
.
gainer said:Perhaps I am crazy. Some others have implied as much. I do not, or very seldom do, use any kind of stop bath. I dump the developer out and dump in the fixer. Also no presoak. I have also, in order to make the developing time a little more consistent (I tkink), poured out enough developer to make room for 1 oz (30 ml) of TF4 concentrate per 16 oz. I have not seen any pinholes or other artifacts. I have used many different films with many different developers. The early TMax 100 gave me airbells that were quite good sized. I cured that with a tiny bit of wetting agent in the developer.
sanking said:Here is what I would suggest for the Ilford films. I am going to suggest eliminating the pre-soak since Ilford recommends this for their films anyway.
So, follow one of two patterns.
Either this,
1. Film directly into eveloper
2. weak acid stop bath, say at about 1/2 normal strength.
3. fix in base or acidic fixer
Or this
1. film directly into developer
2. water stop bath, at least one minute and minimum of five complete changes of water.
3. Fix in alkaline fixer
Either sequence should eliminate the abrupt transfer from base to alkaline or alkaline to base state that could cause the pin holes.
Sandy King
sanking said:Here is what I would suggest for the Ilford films. I am going to suggest eliminating the pre-soak since Ilford recommends this for their films anyway.
So, follow one of two patterns.
Either this,
1. Film directly into eveloper
2. weak acid stop bath, say at about 1/2 normal strength.
3. fix in base or acidic fixer
Or this
1. film directly into developer
2. water stop bath, at least one minute and minimum of five complete changes of water.
3. Fix in alkaline fixer
Either sequence should eliminate the abrupt transfer from base to alkaline or alkaline to base state that could cause the pin holes.
Sandy King
erikg said:Yes, interesting. I think you are right, it is happening during development, that is why they have the donut shape. However, not to dampen all hope, but my normal presoak is 5 minutes. I have never seen quite so many spots as you report, but one per roll is too many, I have enough reasons to loose confidence!
That does dampen my hopes a bit.erikg said:Yes, interesting. I think you are right, it is happening during development, that is why they have the donut shape. However, not to dampen all hope, but my normal presoak is 5 minutes. I have never seen quite so many spots as you report, but one per roll is too many, I have enough reasons to loose confidence!
I'd be glad to. I have a roll of HP5 of the same batch number, exposed in exactly the same way I exposed my test roll. I can send that along with a strip of the developed test roll demonstrating the problem. I'll communicate offline to arrange...sanking said:I wonder if you and Brad would be willing to send me a few samples of the exposed and developed negatives, and perhaps a roll or two of the HP5+ film. I would be very much interested in testing this in my environment to see if the phenomenon repeats itself here. Contact me by email if interested.
Sandy King
Brad Dow said:That does dampen my hopes a bit.
I have a test roll washing now. I won't give up hope until I see the result later tonight, but even if the results are not perfectly clean (and I do agree that one spot on a roll is too much, because it will invariably occur on the very frame you care about), switching to another film may be the answer. I mentioned before, but it's worth repeating, my test rolls of TMY and Tri-X 400 were completely free of spots. Perhaps something in the Ilford manufacturing process makes HP5 it especially sensitive.
I did make one additional change in my most recent test roll (bad experimental practice, I know, but for a patience challenged person...), I used 7.5g/l anhydrous sodium carbonate in place of postassium carbonate. In a private message, Rowland Mowrey was most emphatic that even trace amounts of potassium ion poison fixer. Based on his delcaration, I decided I would use sodium carbonate going forward. In addition, (and this is something Rowland refuted, by the way) I read somewhere on the Net that potassium carbonate had a greater tendency to effervese than sodium carbonate. If the roll is clean, I may try a test run with no presoak and sodium carbonate, since the presoak is a nuisance if it's not really the critical change.
Brad
erikg said:Brad, sorry to hear about your latest results, but I hadn't had my hope up too high. I had a thought about adding a few drops of photo-flo to the developer. I'm thinking harder about switching films, have you had any issues with delta 400? I will also get in touch with Sandy and send him some of my processed film. At the very least he can confirm that we are seeing the same things. It's hard to believe that no one else has seen this on their own negatives. Damn miniature films!
erikg said:I sent off some test films and a spare roll to Sandy. Much thanks to Sandy for taking this on.
I don't know if I mentioned it but my developer is the PF premixed liquid.
And just for the sake of some good news, I just ran some FP-4+ and some Forte 200 that I shot recently in P-Cat, and I do not see any of these defects, just as I never have with any other film than HP-5+. I'm drawn more and more to the conclusion that the issue isn't technique nor presoaks and stop baths but just some interaction between at least some HP5+ and this developer. Why? I don't know. For my part if this means I choose a different 400 speed film, that is fine. I'm open to suggestions if folks have a favorite, keeping in mind that the developer will be P-Cat.
What did we do before Apug? This is a great community.
Erik
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