35mm and pyro something

Rudeofus said:

Yes, there are some published formulas, but on an absolutely minuscule scale compared to the spring flood of Metol based developer formulas. If you have access to underlying data of digitaltruth data, you will see the difference. In this regard, Pyrocat HD with Phenidone is more the exception than the rule, and the Phenidone may well explain why people coming from Metol based developers suddenly noticed an improvement with Pyrocat HD. Add the extra sharpness from high dilution and tanning, and I can understand that large format folks went all enthusiastic.

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Most MQ formulae pre-date the discovery and synthesis of Phenidone which only became available in commercial quantities in 1952/3. Many claime the Metol version Pyrocat M is sharper, however this is because the amount of Metol is very significantly less (in terms of activity not weight) than the Phenidonne in Pyrocat, by a factor of about 10 !.

My experience is that the improvements due to Phenidone are with the long term stability, this is particularly important in Replenished developers, and here the build up of bromide inhibits Metol whereas Phenidone can tolerate much higher levels with no ill effects, replenishment of a PQ developer can be by top up, where as an MQ version needs bleed replenishmennt which is less economic.

I've never seen any claims that Phenidone has any noticeable improvement in terms of image quality compared to Metol, and with Staining developers these improvements are from the Pyrocatechin or Pyrogallol, not the choice of Metol or Phenidone.

Ian

Ian Grant said:

Many claime the Metol version Pyrocat M is sharper, however this is because the amount of Metol is very significantly less (in terms of activity not weight) than the Phenidonne in Pyrocat, by a factor of about 10 !.

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As you noted, Phenidone responds to halide buildup much less than Metol, and this is likely the explanation for Pyrocat MC's higher sharpness. At development sites there is massive local buildup of halide ions, and if the developer gets strongly inhibited by halides, then Mackie lines will appear, giving impression of higher sharpness. Obviously one can also craft sharp Phenidone based developers, such as Xtol or E6 FD, but not by just substituting Metol from some known formula with 10:1 Phenidone.

Ian Grant said:

I've never seen any claims that Phenidone has any noticeable improvement in terms of image quality compared to Metol, and with Staining developers these improvements are from the Pyrocatechin or Pyrogallol, not tehchoice of Metol or Phenidone.

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Phenidone gives 1/2 - 2/3 stops of speed improvement over Metol. You can just take advantage of this by itself, or spend that speed improvement on grain and sharpness improvements.

Rudeofus said:

As you noted, Phenidone responds to halide buildup much less than Metol, and this is likely the explanation for Pyrocat MC's higher sharpness. At development sites there is massive local buildup of halide ions, and if the developer gets strongly inhibited by halides, then Mackie lines will appear, giving impression of higher sharpness. Obviously one can also craft sharp Phenidone based developers, such as Xtol or E6 FD, but not by just substituting Metol from some known formula with 10:1 Phenidone.

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No the explanation you give is flawed, in the case of Pyrocat M (or MC) the Metol level is so low in comparison to the Pyrocatechin that in fact you have a developer closer to a plain Pyrocatechin developer like Windisch surface developer (German version not the incorrect US version).

Rudeofus said:

Phenidone gives 1/2 - 2/3 stops of speed improvement over Metol. You can just take advantage of this by itself, or spend that speed improvement on grain and sharpness improvements.

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Yes Microphen (ID-68) gives that sort of speed increase, however some of that, at least half, is due to the reduced Sulphite level rather than switching to Phenidone, Adox Borax MQ and also Agfa 44 (Agfa Ansco 17) give about 1/3+ speed increase compared to D76/ID-11.

Ilford themselves never made any claims of a speed increase with Autophen (also known as the Axford-Kendall FG developer) which was their commercial PQ version of ID-11 designed for large scale photofinishing. In a series of articles in the BJP essentially describing its evolution speed increase is not mentioned, that doesn't mean there's not a slight increase but the testing was done before the ASA/BS film speed revisions which doubled film speeds and would be less noticeable with the old extra stop exposure.

Microphen (ID-68) exploits the slight speed increase with Phenidone but also combines it with the speed increase from the more optimal level of Sulphite 85g/litre, rather than the 100g/litre of ID-11/D76, to give the 1/2 to 2/3 speed increase.

Ian

Just reporting back ...FWIW, that I have now run through a bottle of Pyrocat-HD (Photoformulary's small bottles) and have to say, I l-o-v-e what's coming out with FP4+ in 35mm. I'm using the box speed recommendation for Pyrocat (no type spec) off the digitaltruth site for 1:1:100 at 18 minutes in 20c, and of course my water runs colder, so my adjusted time is 23:45, but it's still coming out very sweet. As a control, I've done some HP5+ in HC-110 at the same temp in 1:100 dilution for slightly longer (yes by mistake I thought I'd loaded the tank with FP4+) and the results were similarly very good. Differences are marginal, but just seem to require less work for the Pyrocat-HD... though I'll have to do a formal comparison.

Agitation follows the digitaltruth rec of 60 seconds followed by 10-15 seconds every 3 minutes, and I used to call this semi-stand but I think further reading suggests it is more simply "gentle agitation" as true semi-stand - if I have it right - seems to involve a mere one or two interruptions of a full, honest-to-goodness stand development. My default time increase for "gentle agitation" has been set for HC-110 using the difference between Dilution B (1:32) and Dilution H (1:63) as a guide. Straight math. Used that first for 1:50 which I found a simpler formula to work the math of the "pours" for, and have since doubled that for 1:100 as a comparison of high dilution development. On the whole, the coupling of gentle but regular agitation with high dilution seems to be giving very consistent, smooth results. Next move is to reduce my squeegee energy in drying... 'cause I think at high res I'm able to see some scratches I don't want to see, and don't want to necessarily avoid bring the clouds out in my skies and/or touching up the grain because I don't want to reveal these. That's the next fix fer sure.

Also discovered that a fan at my feet is probably not as helpful in offering exhaust for fresh air as I'd like and am going to have to a fan stand to pull the stuff away from my breathing. Yes, I've used goggles, chemical gloves, apron, long sleeves and pants and a dust mask while mixing... and the fog up in the goggles is mind boggling. More comparisons with high dilution using other developers besides HC-110 and Pyrocat-HD may send me in another direction, but so far it's working. Greatest candidate is probably a liquid version of XTOL - if there is one. Someone else suggested Adox's FX-39, and of course I have unopened bottles of PhotoFormulary's TFX-2 and Rodinal. Some sound. reasonably rigorous testing definitely lies ahead so I can reduce the variables and just concentrate on the rest of photography. Meanwhile, I'm a tad reluctant to order a big bottle of Pyrocat-HD until I complete some tests and see whether all the extra precautions are really worth the squeeze. Thanks for all the input here!

I should add that LFA Mason states that a speed increase for phenidone is only seen in high sulfite low pH developers. Certainly not the case with staining developers

Gerald C Koch said:

I should add that LFA Mason states that a speed increase for phenidone is only seen in high sulfite low pH developers. Certainly not the case with staining developers

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My experience based on using Pyrocat HD for over 10 years (initially alongside Xtol) is it does give slightly better speed. As both contain Phenidone and Xtol also contains a high sulphite level that would appear to contradict Mason. However it's more likely the super additivity of Pyrocatechin and Phenidone along with slightly longer development of the shadows and the staining effects on the mid tones and particularly the highlights.

Hard to explain but the greater the exposure and subsequent development the higher the staining component of the final silver/stain density. With an old fashioned Pyro plate developer (before meters) plates were often over-exposed, the developers were contrasty and vigorous, however the Pyro developers tan and stain as they develop slowing development of the highlights significantly, this is like a self masking effect.

One benefit of Pyrocat HD and other modern Pyro developer which is often not mentioned is how much easier the negatives are to print.

Ian

Don't know how this site rates in terms of those developing film as a % of the users, how serious they are about their images and all the rest, but I'd assume pretty serious. But to my knowledge, we don't run polls here.

FWIW, just as a matter of interest, I posted a poll on favorite developers on the rangefinder forum, and so far with 120 plus logging their go-to developers, less than 3% have suggested they use Pyrocat-HD or similar, and 0% for Pyrogallo.
The three most common categories (meaning Ilford equivalents as well): 34% for HC-110; 30% for Rodinal; and 20% for D-76; 15% for XTOL and 5% for T-MAX. Numbers add up to more than 100% because folks were allowed to list more than one. Key thing is most folks aren't listing more than one. This was framed as "your most commonly used". Not a lot of roll your owns (that was a category, too).

Biggest suprise is that all forms of Pyro (pyrocat and pyrogallo) registered so invisibly. Maybe those folks are out in the field, shy, or just not interested in "sharing"? Fair enough. We've only had 120 some voters so far. More to come I hope.

JWMster said:

But to my knowledge, we don't run polls here.

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No problem - just start a new thread, and use the "Create a Poll" option.
My guess is that the numbers for pyro users would be similar to the numbers of people who compound their own developers.

JWMster said:

Don't know how this site rates in terms of those developing film as a % of the users, how serious they are about their images and all the rest, but I'd assume pretty serious. But to my knowledge, we don't run polls here.

FWIW, just as a matter of interest, I posted a poll on favorite developers on the rangefinder forum, and so far with 120 plus logging their go-to developers, less than 3% have suggested they use Pyrocat-HD or similar, and 0% for Pyrogallo.
The three most common categories (meaning Ilford equivalents as well): 34% for HC-110; 30% for Rodinal; and 20% for D-76; 15% for XTOL and 5% for T-MAX. Numbers add up to more than 100% because folks were allowed to list more than one. Key thing is most folks aren't listing more than one. This was framed as "your most commonly used". Not a lot of roll your owns (that was a category, too).

Biggest suprise is that all forms of Pyro (pyrocat and pyrogallo) registered so invisibly. Maybe those folks are out in the field, shy, or just not interested in "sharing"? Fair enough. We've only had 120 some voters so far. More to come I hope.

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Your numbers are pretty much what I would expect from posts on APUG. There is a small dedicated following for staining developers. I don't consider those that try them for awhile and go back to conventional developers.