Questions on "splotchy development"

Raghu Kuvempunagar

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I was reading this review of 510-Pyro earlier and found this observation interesting:

"After using the semi-stand agitation method and the Ilford method, I have found this splotchy development problem occurs with both modes. The problem doesn’t crop up in roll film"

Any idea why sheet film is more prone to development problems like uneven development, streaks, blotches, etc than roll film even when regular intermittent agitation scheme is used? I was under the impression that such problems were due to insufficient agitation which the Ilford agitation scheme would take care of. Is this the case with other developers too?
 
Surface area and agitation even with semi stand or regular agitation. With 120 (or 35mm) agitation easily remixes the developer, from areas of more localised exhaustion, with 5x4 or larger you need to be more careful with agitation.

It's also an issue with PMK, which give similar problems with rotary processing, part of the problem is the Pyrogallol itself which oxidises faster than other developing agents during use.

Ian
 
I have found all forms of Pyro-based developers at some risk of this, irrespective of agitation method. When I use PMK, I agitate every sheet by hand in a tank every 15sec - which is to say - more-or-less continuous agitation. My considerably painful tests last year showed that low frequency/high dilution (Semistand and EMA) sheet film development in open tanks needed absolutely minimal negative support or I'd see bromide drag streaks along the edges of the supporting frame. This was true even with Pyrocat-HD.
 
I've been using Pyrocat HD for around 18 years now, it's been my only film developer for 16 years, that's with 35mm, 120, 5x4, 7x5 and 10x8, as well as 9x12 and Quarter plate. That's also with a variety of tanks, Paterson, Jobo 2000, Yankee, Paterson Orbital, and dish processing. That's hundreds of rolls and hundreds of sheets of film. I have never had any uneven development with Pyrocat HD.

Sandy King devised and formulated Pyrocat HD because of the issues of uneven development with PMK and sheet film. The issue in this article is nothing new, it's been a problem with PMK and later 510 Pyro with some types of processing, rotary, and in spiral, as Spearman tanks.

There may be an issue that's being overlooked, and that's the water being used to mix 510 Pyro.

Ian
 
I've been using Pyrocat HD for around 18 years now, it's been my only film developer for 16 years, that's with 35mm, 120, 5x4, 7x5 and 10x8, as well as 9x12 and Quarter plate. That's also with a variety of tanks, Paterson, Jobo 2000, Yankee, Paterson Orbital, and dish processing. That's hundreds of rolls and hundreds of sheets of film. I have never had any uneven development with Pyrocat HD.

Sandy King devised and formulated Pyrocat HD because of the issues of uneven development with PMK and sheet film. The issue in this article is nothing new, it's been a problem with PMK and later 510 Pyro with some types of processing, rotary, and in spiral, as Spearman tanks.

There may be an issue that's being overlooked, and that's the water being used to mix 510 Pyro.

Ian

The instances where I have seen unevenness with Pyrocat-HD have been when doing very long/very dilute development. This tactic is known to be risky and I didn't mean to impugn Pyrocat as being particularly a problem. It's the process that's tricky and causes potential issues. In ordinary use, I've never seen Pyrocat splotch or otherwise show unevenness of development.
 
The instances where I have seen unevenness with Pyrocat-HD have been when doing very long/very dilute development. This tactic is known to be risky and I didn't mean to impugn Pyrocat as being particularly a problem. It's the process that's tricky and causes potential issues. In ordinary use, I've never seen Pyrocat splotch or otherwise show unevenness of development.

Any dilute developer used that way can give these issues. Sandy King's method of reduced development includes occasional agitation to avoid problems.

Ian
 
Any dilute developer used that way can give these issues. Sandy King's method of reduced development includes occasional agitation to avoid problems.

Ian

Yes, this is consistent with my own testing with film developed using hangers and open tanks. A true "stand" development (no agitation after initial) is susceptible to bromide drag, streaking, etc. Agitating once at the midpoint (semistand) pretty much eliminates this. Agitating occasionally throughout the standing period (Extreme Minimal Agitation) also solves the issue.

However ... even using semistand or EMA, I found that attempting to hold the 5x4 sheets in traditional film hanger frames or (heaven forbid) a Yankee sheet film holder/tank, caused all manner of mischief. I suspect - but cannot prove - that this is caused by developer trapping happening along the edge of the hanger frame or holder. The only thing that did work consistently well (at least among those things I tried) was using a minimal "pinch" style hanger that held the film by the absolute minimum.

I know that other practitioners use things like open trays, PVC pipe schemes, and automatic roller processors, none of which I tried. (Interestingly, with roll film and 35mm, I got streak-free results simply by resting the reel on a rubber stopper to keep it off the bottom of the tank.)

There was one exception to all this. I use semistand to shoot- and process very old film. I've successfully processed Super-XX that went out of date in 1961, for example. The only film that refused to cooperate was very old 3x2 sheets of Plus-X which streaked every time in Pyrocat-HD semistand. This same film processed semistand in D-23 was flawless. I found this of interest because overnight film processing in D-23 has a long and venerable history in retail film processing in photo shops of a bygone era here in the US.
 
Bob Carnie has an interesting work around for the woes of PMK Pyro which is to replace the working solution midway during the developing process by fresh working solution. One could perhaps use the same approach with 510-Pyro? But this would make developing with 510-Pyro even more expensive.

Steve Sherman, the most ardent advocate of (extreme) minimal agitation techniques, recommends a substantially long and vigorous initial agitation (at least 1.5 minutes) to prevent uneven development. But this might not work well with Pyrogallol based developers, especially very dilute ones, as vigorous agitation can oxidise Pyrogallol faster.
 
Bob Carnie has an interesting work around for the woes of PMK Pyro which is to replace the working solution midway during the developing process by fresh working solution. One could perhaps use the same approach with 510-Pyro? But this would make developing with 510-Pyro even more expensive.

Steve Sherman, the most ardent advocate of (extreme) minimal agitation techniques, recommends a substantially long and vigorous initial agitation (at least 1.5 minutes) to prevent uneven development. But this might not work well with Pyrogallol based developers, especially very dilute ones, as vigorous agitation can oxidise Pyrogallol faster.


My standard initial agitation for semistand is 2 mins and for EMA it's 90sec, as you say, "vigorously" ...
 
Could Copper/Iron ions in tap water can possibly make Ascorbic acid in the working solution of 510-Pyro go bad quickly?

Quite possibly Iron & Copper ores have been mined extensively in Newfoundland. Iron is also used in some areas for water treatment. The higher the dilution the greater chance of an issue.

One problem with non-commercial home-made developers is the lack of adjuncts, chelating agents, traces of surfactant, etc.

Ian
 
How much space is there between the sheets of film when you get this blotching?
 
If he's using Jobo spirals 4-5mm. I think he's using the newer versions compared to my mid 1970s Jobo 2000 series inversion tanks.

The issues with Ascorbic Acid and iron in the water could account for suddend localised collapse and with no protection from the ascorbic acid the Pyrogallol would very rapidly oxidise. It's a know issue with Xtol.

Ian
 
As the recommended working solutions of 510-Pyro, 1:100 to 1:500, have very little ascorbic acid and pyrogallol, I guess even a trace of iron/copper in water can potentially make the developer collapse.
 
As the recommended working solutions of 510-Pyro, 1:100 to 1:500, have very little ascorbic acid and pyrogallol, I guess even a trace of iron/copper in water can potentially make the developer collapse.

Some years ago I wrote a Spreadsheet comparing various of these highly dilute developers at their actual dilution for use, I still have it but need to remember what I named the file :D I know Pyrocat HD was included so it's not a file from the 1990s :).

I'm fairly sure I compared Rodinal, Pyrocat HD, 510 Pyro, FX1 &2, Beutler Windisch's Surface Developer etc. One of the things I looked at was exhaustion and the minimum volume of chemistry needed. I'll look in the next days.

Ian
 
Could Copper/Iron ions in tap water can possibly make Ascorbic acid in the working solution of 510-Pyro go bad quickly?

I both mix stock developer (if I am making my own) and working strength with distilled water, and more recently, for Pyrocat-HD Part A, Propylene Glycol ( though I probably could use deonized as well). I started doing this years ago when I noted that seasonal variations in tap water were changing developer behavior. Is this is strategy that might work for you?
 
The problem is not general under-development, from the depleting effect of contaminated water, but blotchy development. This suggests very local degradation, which seems odd as any offending ions would be evenly distributed in the tap water.
As we all already know, agitation is intended to remove local variations in developer exhaustion. It would seem reasonable, therefore, to ignore the strictest theological dogma on minimum agitation and agitate a bit more.
This is not to decry the use of cleaner water, but we’d need to see an analysis of the offending tap water before we could pin the blame securely on the local water supplier.
 
The problem is not general under-development, from the depleting effect of contaminated water, but blotchy development. This suggests very local degradation, which seems odd as any offending ions would be evenly distributed in the tap water.
As we all already know, agitation is intended to remove local variations in developer exhaustion. It would seem reasonable, therefore, to ignore the strictest theological dogma on minimum agitation and agitate a bit more.
This is not to decry the use of cleaner water, but we’d need to see an analysis of the offending tap water before we could pin the blame securely on the local water supplier.

Concur completely. The description sounds like an artefact of bromide drag not faulty water (though I still think distilled is best practice for mixing developers). There should never be a single "doctrine" of minimal agitation. How much to agitate - even "minimally" will be a function of film type, developer, and - quite critically - how the film is suspended in the developer.

One of the various reasons I open tank process is that it allows me to support rollfilm reels above the bottom of the tank (via a rubber stopper) and to hang sheet film horizontally so that the bottom edge iswell above the bottom of the tank. This essentially eliminated bromide drag effects when agitating even only at the beginning and once in the middle of a 60 minute stand. My (very much) unproven hypothesis is that gravity pulls the bromide byproducts toward the very bottom of the tank during long stands and this technique keeps the film out of that zone .... but some form of proof is required for which I do not have the instrumentation.
 
Distilled water for working solution is no doubt a great idea but impurities can come from other sources as well. For example, sulphite and carbonate can have traces of metals depending on the source and purity. Of course in the specific case of 510-Pyro, there's no sulphite or carbonate involved, but TEA could be a possible source of impurities. Anyway, one would expect the manufacturer's R&D to anticipate such issues and address them during the design and production of the developer than recommending use of distilled water. Kodak, for instance, added DTPA to its XTol formulation to address the sudden death problem.

BTW the review says development problems persisted even when Ilford agitation scheme was used. So minimal agitation isn't the only cause of the reported problems.
 
Have we ruled out faulty film or contamination of the film itself? That would be evident, whatever the agitation scheme.
 
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