Pinholes with 35mm HP5 from Pyrocat-HD?

[Brad Dow]

I've been using the pre-mixed Formulary version of Pyrocat-HD (in water) to develop 35mm HP5, and have been extremely pleased with the results, with one exasperating exception: it seems virtually every negative prints with several tiny black spots visible in any pale, untextured areas, effectively spoiling the negative. These spots are typically very small, hardly bigger than a grain aggregate, as if several extremely tiny bits of dust had settled on every negative at taking time. I pre-soak in distilled water for 2 minutes, develop for about 10 minutes in developer diluted 1:1:100 in distilled water, rinse in tap water, and fix in TF4.

I have experienced this frequently in 4x5, with 120 once in a while, but never in many, many thousands of exposures developed in D76 variants have I ever experienced this problem in 35mm. I wondered, could my camera be that dusty? So I scrupulously dusted it, inside and out, and refrained from changing lenses for the next several rolls. Nonetheless, the next batch of negatives exhibited the same problem.

It seems a bit unlikely that so venerable a formula as Pyrocat-HD would produce this effect, but my results seem fairly solid and I can't think of anything I might be doing to cause the problem.

Thoughts, suggestions?

 

[noseoil]

Are you re-using your fixer? Strain it with a coffee filter. This sounds like a processing error. If it were pin holes, as you wrote in the thread, I would guess an acid stop. tim

 

[sanking]

I've been using the pre-mixed Formulary version of Pyrocat-HD (in water) to develop 35mm HP5, and have been extremely pleased with the results, with one exasperating exception: it seems virtually every negative prints with several tiny black spots visible in any pale, untextured areas, effectively spoiling the negative. These spots are typically very small, hardly bigger than a grain aggregate, as if several extremely tiny bits of dust had settled on every negative at taking time. I pre-soak in distilled water for 2 minutes, develop for about 10 minutes in developer diluted 1:1:100 in distilled water, rinse in tap water, and fix in TF4.

I don't understand the mechanism. If there are spots on the negative it would seem to me that they would block some light and print as light dots, not black dots?

Logically, black dots on the print would would from pin holes on the negative.

Sandy

 

[Brad Dow]

Are you re-using your fixer? Strain it with a coffee filter. This sounds like a processing error. If it were pin holes, as you wrote in the thread, I would guess an acid stop. tim

Tim,

I am using re-using the fixer, strained between each use, but I'm quite careful not to over use it and the most recent flawed batch was with fresh fixer. The stop is five changes of tap water.

 

[Brad Dow]

I don't understand the mechanism. If there are spots on the negative it would seem to me that they would block some light and print as light dots, not black dots?

Logically, black dots on the print would would from pin holes on the negative.

Sandy

Sandy,

I don't understand the mechanism, either. My first though was dust on the negatives at taking time, but even after a meticulous cleaning of the camera, the next three rolls had literally dozens of these black spots, more than could have been caused by dust. Also, the spots are typically quite a bit smaller than the sort of spots caused by dust on a 4x5 negative, so small that are completely hidden by the slightest bit of texture.

My next thought was pinholes due to the potassium carbonate. I've never actually experience pinholes, but I expect them to bright as black spots. My understanding is that while 7.5g/l of potassium carbonate in the developer might be enough to cause pinholes if followed by an acid stop, it seems very unlikely with a water rinse. And with a film like HP5, I'd even be surprised to see pinholes with an acid stop.

It feels like I'm grabbing at straws here, but the only changes I've made in my processing routine are: introduce a pre-soak, change developer, and extend the wash time from 5 minutes to 20 minutes. (My previous standard developer for HP5 was a metol-free D76 variant: 2.5g metol + 2g borax + 25g sulfite / liter.)

I've been otherwise delighted with the results from Pyrocat-HD, which makes this experience particularly frustrating.

 

[sanking]

Sandy,

I don't understand the mechanism, either. My first though was dust on the negatives at taking time, but even after a meticulous cleaning of the camera, the next three rolls had literally dozens of these black spots, more than could have been caused by dust. Also, the spots are typically quite a bit smaller than the sort of spots caused by dust on a 4x5 negative, so small that are completely hidden by the slightest bit of texture..

Explain this again. Are the black spots on the negatives, or on the prints that you made from the negatives? If there are black spots on the negatives they would hold back light and this would give lighter spots on the print, which probably would not be visible in highlight areas. If you have pinholes on the negatives they will print as black spots on the print.

Of course, if you have dust on the negative during exposure this will also result in pinholes on the negative, which would print as black spots on the print.


Sandy

 

[RJS]

Pinholes

I've been using PMK with HP5 with no such problems. Don't use a presoak, plain water stop. Is it possible you have a bad batch of film? Have you tried a roll from the same batchin a different developer? Otherwise, try lighting incense, facing east, turning around three times and cross your fingers while loading your developing reels.

Is it possible there is a problem with reels/tanks?

 

[don sigl]

Brad:

I use Pyrocat with hp5 120 and 8x10, and I don't see the problems you are having. However, I'm mixing my own and I'm using the Sodium Carbonate substitution. This may not make any difference, but I thought I would throw it out there as a straw to grab.

I get most of my compounds from the Formulary, but I don't buy the premixed packages. Maybe if you mixed a batch of your own, you could determine if it was the chemistry. Its not likely, but it is a variable you could check out.

 

[erikg]

I have seen the same thing, I believe. Very small areas of no density on the neg that print as black spots. I posted a question here, but nothing conclusive came up. Looking at the film under magnification the spots look like a speck of undeveloped emulsion, not a hole, and they have a sharp edge, unlike an air bubble, and they are much smaller than any air bubble defect that I have seen. Same combo, 35mm HP-5 with pyrocat. Presoak, Water stopbath, non-hardening fix. I haven't seen this with 8x10 and 120 HP-5. Very strange, but I do like the developer a lot.

 

[Brad Dow]

I have seen the same thing, I believe. Very small areas of no density on the neg that print as black spots. I posted a question here, but nothing conclusive came up. Looking at the film under magnification the spots look like a speck of undeveloped emulsion, not a hole, and they have a sharp edge, unlike an air bubble, and they are much smaller than any air bubble defect that I have seen. Same combo, 35mm HP-5 with pyrocat. Presoak, Water stopbath, non-hardening fix. I haven't seen this with 8x10 and 120 HP-5. Very strange, but I do like the developer a lot.

Exactly, and better described. In most cases, the black specks are so small that they would hardly be visible in an enlargement much less than about 4x.
Have you seen the phenomenon with other developers?

 

[erikg]

Exactly, and better described. In most cases, the black specks are so small that they would hardly be visible in an enlargement much less than about 4x.
Have you seen the phenomenon with other developers?

No, I haven't, and I have used HP-5 for many years. I use stainless tanks and reels, how about you?

 

[Brad Dow]

Explain this again. Are the black spots on the negatives, or on the prints that you made from the negatives? If there are black spots on the negatives they would hold back light and this would give lighter spots on the print, which probably would not be visible in highlight areas. If you have pinholes on the negatives they will print as black spots on the print.

Of course, if you have dust on the negative during exposure this will also result in pinholes on the negative, which would print as black spots on the print.


Sandy

The negatives shows very tiny, sharply defined clear specks, which print as black specks, hardly bigger than a grain aggregate. My first thought was dust on the negative at taking time, but I believe that is not the problem.

 

[Brad Dow]

No, I haven't, and I have used HP-5 for many years. I use stainless tanks and reels, how about you?

Yes, Kindermann 1-liter stainless tanks and Hewes reels.

 

[sanking]

Yes, Kindermann 1-liter stainless tanks and Hewes reels.

OK, so you have very tiny transparent spots on the film that print as dark spots.

I found a couple of pages that discuss similar problems, though not specific to this situation, and in fact I am not sure that anything here is pertinent, but I found it interesting.

Dead Link Removed

http://albumen.stanford.edu/library/monographs/sunbeam/chap44.html

Assuming that the tiny transparent spots are not actually small air bubbles, created by detachment of the emulsion from the base of the film, the most likely culprtis in my opinion would be.

1. Minute dust particles on the film during exposure.

2. Minute air bubbles on the emulsion of the film during development that because of unusual static charge remain in the same spot throughout develoment, depriving those spots of developer chemistry.

3. An imperfection in the emulsion of the film that left minute points of the film without sensitized material.

For the life of me I can not think of how this could be caused by the developer, unless it contained minute particles of some substance that on contact with the emulsion would kill the latent silver image.

Just to test the processing stage, I suggest you try developing without a pre-soak.

Sandy

 

[Brad Dow]

Sandy,

As unlikely as it seems, let's say the clear specks on the negative are pinholes due to the carbonate, and suppose I wanted to try a less aggressive accelerant. What might you suggest? Perhaps 5g/l of borax or metaborate in the working solution? Would the pyrocat still be active at the lower pH? Provided it is still active, this might work for me. My target contrast is low (for enlarging with a condenser head), and I can live with longish times.

 

[sanking]

Sandy,

As unlikely as it seems, let's say the clear specks on the negative are pinholes due to the carbonate, and suppose I wanted to try a less aggressive accelerant. What might you suggest? Perhaps 5g/l of borax or metaborate in the working solution? Would the pyrocat still be active at the lower pH? Provided it is still active, this might work for me. My target contrast is low (for enlarging with a condenser head), and I can live with longish times.

Brad,

Pyrocat-HD needs a working pH of at least 10.8 or 10.9 and it will not work with either borax or metaborate. However, pin holes normally appear when taking the film from a very alkaline solution to an acetic one, and you are using a water stop bath, right?

I suggested dropping the pre-soak on the chance that it is either very alkaline or may contain something that is causing the emulsion to detach from the base.

Sandy

 

[Brad Dow]

OK, so you have very tiny transparent spots on the film that print as dark spots.

I found a couple of pages that discuss similar problems, though not specific to this situation, and in fact I am not sure that anything here is pertinent, but I found it interesting.

Dead Link Removed

http://albumen.stanford.edu/library/monographs/sunbeam/chap44.html

Assuming that the tiny transparent spots are not actually small air bubbles, created by detachment of the emulsion from the base of the film, the most likely culprtis in my opinion would be.

1. Minute dust particles on the film during exposure.

2. Minute air bubbles on the emulsion of the film during development that because of unusual static charge remain in the same spot throughout develoment, depriving those spots of developer chemistry.

3. An imperfection in the emulsion of the film that left minute points of the film without sensitized material.

For the life of me I can not think of how this could be caused by the developer, unless it contained minute particles of some substance that on contact with the emulsion would kill the latent silver image.

Just to test the processing stage, I suggest you try developing without a pre-soak.

Sandy

Thanks for the suggestions. I'm pretty sure it's not dust, but I really should do a more controlled experiment before jumping to any more conclusions. I'll try a more controlled test and report what I find.

I have on hand two rolls of HP5 with identical batch numbers, bought at the same time. I'll run them through the same camera, exposing 18 frames to to clear North sky, and then develop them with an identical process (no-presoak, water stop, TF4 fix, 20 minute wash, identical agitation), and print enough frames from each to see if there's a clear pattern of problems with one not shown by the other.

Brad

 

[Brad Dow]

Brad,

Pyrocat-HD needs a working pH of at least 10.8 or 10.9 and it will not work with either borax or metaborate. However, pin holes normally appear when taking the film from a very alkaline solution to an acetic one, and you are using a water stop bath, right?

I suggested dropping the pre-soak on the chance that it is either very alkaline or may contain something that is causing the emulsion to detach from the base.

Sandy

I was afraid the pH would be too low with borax or metaborate. I will try omitting the pre-soak in my next test. Even though the pre-soak was steam-distilled water, I did notice a surprising amount of what seemed like effervescence during my last processing cycle, when I inserted the film into the pre-soak water. It lasted for most of the 2-minutes.

If the more controlled test I describe above confirms the problem as being associated with Pyrocat-HD, would it make any sense to you to try adding adding 0.5 g/l of borax to the water stop to create a more gentle transition from the developer. I typically prepare 5 liters of tempered water in advance, because the temperature of my tap water is prone to change during the course of a ten minute development cycle. Adding a bit of borax stock solution would be a simple matter.

Another thing to try would be to prolong the pre-soak until the there's no sign of effervescence.

Brad

 

[erikg]

I have on hand two rolls of HP5 with identical batch numbers, bought at the same time. I'll run them through the same camera, exposing 18 frames to to clear North sky, and then develop them with an identical process (no-presoak, water stop, TF4 fix, 20 minute wash, identical agitation), and print enough frames from each to see if there's a clear pattern of problems with one not shown by the other.

Brad

I'll run a similar test with my process, and we can compare results. I guess I'm glad it's not just me, but I will be happier if we get to the bottom of this.

Best,
Erik

 

[Brad Dow]

I'll run a similar test with my process, and we can compare results. I guess I'm glad it's not just me, but I will be happier if we get to the bottom of this.

Best,
Erik

That would be great. It's worth the trouble. In my previous posts I perhaps understated how pleased with the developer I have been (apart from the problem described here).

Working in 120 and 4x5, in the past year or two I've tested an almost embarassing array of non-staining formulas, looking for the magical combination. The results I found were more alike than different, and I converged on a fairly conventional metol-borax-sulfite formula that seemed to balance practical factors, like storage and mixing convenience, developing times, fog, etc. However, I recently resumed work in 35mm, and have been unsatisfied, especially trying to get print quality in 35mm that I'm used to from 120 and 4x5. A very knowledgeable friend whom I greatly respect said he had settled on Pyrocat-HD for 35mm when Rodinal became unavailable, and was very pleased with it. From the first my Pyrocat-HD negatives stood out, with lovely grain, adequate speed, great sharpness, and, most of all, noticeably better highlight gradation---the thing I had been most missing in working with these tiny negs.

My own theory on what makes it special is that it allows higher zones to be represented by silver density that wth a non-staining developer would be associated with silver densities at least two stops lower. My own down-and-dirty densitometry is enlarger based: I expose a series of 1-stop exposure increments, project it as I would any negative with my condenser enlarger, and record brightness with a MetroLux II baseboard probe. While this has all kinds of problems as proper densitometric practice, it does introduce the real-world issue of diffraction in the negative, which is progressive with silver density, especially using condensor illumination. When measured this way, negatives developed in non-staining developers shows a progressive flattening of contrast from about Zone VII on. At a certain point (in Metrolux terms, about log 2.2 above film base + fog), an effective upper limit is reached, regardless of developer. This does not accord with what Ilford and Kodak say about this type of film. We're not supposed to see an effective shoulder until around Zone XV. That may be so when density is measured with a proper densitometer, but for me, in my world of enlargement with condensors, that is certainly not the case. The first thing I noticed when I ran the same sort of test with a Pyrocat negative was that this shoulder was hit at least two stops later, with the curve staying nice and straight right up to around Zone X.

In practice, working with D76 variants I find that if I expose sufficiently to get good blacks and visible separation in the lowest values, the highs flatten out, and no sane amount of print manipulation can reveal the missing separation. This for me was the big disappointment with the smaller negs. Everything else I can happily live with. But my Pyrocat negs were immediately a different story. Rick darks AND good, printable highlight separation.

Anyway, that's my theory.

Brad

 

[Brad Dow]

I performed a fairly carefully controlled experiment, as promised, in an attempt to clarify the problem I reported at the top of this thread. I'm afraid the results are clear and very disappointing.

I passed a 36-exposure roll of fresh HP5 (expiration date Jan 2010) through a carefully cleaned M4 with a 50mm lens, exposing 36 frames of clear northern sky, placing exposure on Zone V (EI=200). I then cut the film in half and developed both halves with a process that differed only in the developer (one roll in Pyrocat-HD 1:1:100, the other in EK D76 1:1):

No pre-soak, 9.5 minutes in 1-liter of fresh developer at 73F, 5 changes of tempered tap water, 5 minutes in TF4, 20 minutes wash at around the same temperature. I processed both strips simultaneously, agitating them identically during development: 20 inversions the first minute, 6 each subsequent minute, followed by sharp whacks with the heel of my hand.

Once the negatives were dry I used a 10x loupe to examine 15 negatives in each strip on a light table, counting clear spots. On the Pyrocat developed strip I counted 93 clear spots, varying in size from tiny, pin-like specks visible only with the loupe to specks large enough to see with the un-aided eye. On the D76 developed strip I counted only 2 clear spots, and I'm not sure those were not distant birds, because they had a less well-defined character.

I projected a few of the Pyrocat frames in the enlarger at 10x and examined a few clear spots on the baseboard with a Peak grain focusser. In each case they appeared as a clear rim surrounding a tiny patch of normal density. The shape of the rim varied from round to various eliptical variants. This is the first time I've seen such a thing, but it appears that something in the Pyrocat interacted with the emulsion to produce bubbles, which adhered to the emulsion surface, trapping enough developer inside to create a center of normal density, but excluding developer from where they contacted the emulsion.

Brad

 

[lee]

Hi Brad,

I would recommend using a pre-soak or pre-wash with pyrocat-HD. Reading this thread it has always occurred to me that the issue was "air bells". 20 inversions in the first minute seems to me to be too much. I like to use about as many as I can get done in the first 10 or 15 seconds and then 10 seconds on the minute. I never get "air bells" with this method and I always twist the can while inverting.

lee\c

 

[Tom Hoskinson]

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.

 

[sanking]

The shape of the rim varied from round to various eliptical variants. This is the first time I've seen such a thing, but it appears that something in the Pyrocat interacted with the emulsion to produce bubbles, which adhered to the emulsion surface, trapping enough developer inside to create a center of normal density, but excluding developer from where they contacted the emulsion.

Brad

I think the problem is airbells. Why this happened with the negatives developed in Pyrocat and not in D76 I am not sure. However, what appears to be happening is that the emulsion of the HP5+ fim loses contact with the film base, just ever so slightly, and tears at this point. Since Pyrocat works at a higher pH than D76, the problem is possibly pH related.

Question is, why does this happen with only HP5+, and why so rare? My guess is that there are some kind of trapped gases in the HP5+ emulsion that for some reason react violently with high pH, but apparently only in some conditions, and perhaps only with certaim emulsion batches. I have used HP5+ extensively in 35mm, medium format and sheet film and never seen anything like this.

Somehow the water has be to be a factor, either the mix of the -HD or what you are using to pre-soak and develop. I would suggest that you repeat the tests, but use plain tap water for both the pre-soak and the developer. If those does not work, I am about out of suggestions.

Sandy

 

[Brad Dow]

Thanks, everyone, for the input. I'll probably try a few more things. If I learn anything that might be useful, I'll report it.

One additional note: I examined two Kodak films (TMY and TX400) that had been developed in Pyrocat, following the same processing sequence I used in the test case. Both were completely free of the artifact described here.

Brad