Pyrocat-HD in Jobo and high acutance?

[wiggywag]

Hi!

I'm considering using Pyrocat HD in my Jobo Rotary Expert drum system, and wonder if I can achieve high acutanse with continous agitation with this developer? I have seen some pyro negatives which are extremely sharp and wonders if the same is possible with this combination? Does Pyrocat-HD gives greater edge effect than e.g. Xtol in Jobo rotary drums?

Thanks

[Jay DeFehr]

Yes. You will see more edge effects with intermittent agitation, but due to the tanning, you'll still see some with continuous agitation, depending on how closely you look. Whether you will see a difference in actual prints is an open question.

[Gem Singer]

Pyrocat-HD oxidizes rapidly when continuously rotated in a Jobo drum.

It's much more suited to slow intermittent agitation or stand development.

For a discussion of edge effects, see: S.Anchell and B.Troop, "The Film Development Cook Book".

[David Aimone]

Isn't Pyrocat-MC better adapted for continuous rotation?

[dasBlute]

Sandy King: [pyrocat-hd] is "suitable for all types of development methods, including rotary, normal agitation, minimal agitation and stand development".

I use TXP in pyrocat-hd in a jobo, continuously rotating, all the time. I get results like this (http://www.flickr.com/photos/stormiticus/6191627833/lightbox/). Maybe I don't get the 'edge effects' as much as stand development, but I'm contact printing not enlarging, so I might not notice.

Gem Singer: "Pyrocat-HD oxidizes rapidly when continuously rotated in a Jobo drum"

What is "rapidly"? one minute? five? and what is the effect of this?

[Andrew O'Neill]

Pyrocat-HD works very well for both tray and rotary processing. If acutance is what you are after, then work in trays. If extreme acutance is what you are after, then work in drums/tubes using the semi-stand/stand development technique. Stand the drum/tube upright and fill completely with developer. Use a more dilute solution of pyrocat-hd. I use 5ml of each A and B solution in 1200ml water for an 8x10 BTZS tube.

[Jay DeFehr]

David,

PMC, like all the Pyrocats, is suitable for rotary processing because I think that's how it was tested during formulation, but I might be wrong about that. That shouldn't suggest these developers aren't also well suited to intermittent agitation.

Pyrocats, like 510-Pyro, are general purpose developers, and will work well under most processing conditions, with most films. Hypercat, on the other hand, was formulated specifically for intermittent agitation, and rotary processing results in significant film speed loss, and decreased acutance compared to intermittent agitation.

The original Hypercat formula, the first of its kind, I think, was also a general purpose developer formulated to be compatible with rotary processing, but since it was nearly identical in performance to 510-Pyro, with some limitations 510-Pyro doesn't suffer, and more complex, I decided I wanted to formulate a developer that optimized the special characteristics of catechol, as simply as possible, and that developer is Hypercat II.

For the sake of comparison, here are the two formulas:

Hypercat

A

Ascorbic acid 2g
Catechol 10g
Phenidone 0.25g
Benzotriazole 0.25g
Propylene glycol to 100ml

B

Sodium hydroxide 10%


Hypercat II

A

Ascorbic acid 1g
Catechol 10g
Propylene glycol to 100ml

B

Sodium carbonate 20%
-or-
Potassium carbonate 75%
-or-
Sodium hydroxide 10%

Eliminating the phenidone from HII resulted in no loss of speed or activity with intermittent agitation, and allowed me to also eliminate the benzotriazole, and to halve the ascorbic acid*. Phenidone fogs at pH high enough to activate the catechol, and requires an antifoggant, like benzotriazole or potassium bromide. Eliminating the second developing agent resulted in a surprising increase in sharpness and compensating effects. The compensating effects are apparent when comparing films developed with continuous agitation to those developed with intermittent agitation. Films developed with intermittent agitation show full film speed, but those developed with continuous agitation show a loss of 1/2- 1 full stop, depending on the film tested.

Hypercat II is in a different developer category than the original Hypercat, or the Pyrocats, or 510-Pyro. HII is a single agent tanning/staining acutance developer, similar to some very old catechol formulas, but updated to address the issues of keeping properties that made the old formulas so inconvenient, and adapted to modern film stocks. HII can be used in rotary processing, but with a speed loss, and sharpness will not be significantly better than with the original Hypercat, the Pyrocats or 510-Pyro.

HII with intermittent agitation is quite impressive. I use it with film exposed in very old cameras with simple, uncoated lenses, which I imagine is what the first catechol developers were formulated for. Here's an example made with an old Kodak 2A folder and TMY-2:

http://farm6.static.flickr.com/5055/5505192693_74d4d85e7b_b.jpg

I hope the image shows up.

* Originally, HII used only 0.5g ascorbic acid, but I saw streaking in a few rolls processed with very low frequency agitation, so I lost my nerve and doubled it to 1g. I haven't seen any more streaking, but I'm not sure the increased ascorbic acid has anything to do with it. My goal in keeping the ascorbic acid to a minimum is to eliminate any developing action on the part of the ascorbic acid, and indeed, HII without ascorbic acid has the same activity, but more general stain and it oxidizes more rapidly.

[Gem Singer]

das Blute,

Pyro developers are known to oxidize more rapidly than PQ or MQ developers.

We got dark brown oxidation with freshly mixed 1:1:100 Pyrocat-HD in a Jobo Expert Drum after seven minutes of continuous agitation on a motor base.

The Ilford HP-5+negatives were slightly under-developed, but still printable.

[David Aimone]

lovely image, Jay!

[Jay DeFehr]

Thanks, David. It's a lot of fun to use those simple cameras, but composing with those little finders is a challenge.

[Jay DeFehr]

Gem,

It doesn't take much oxidation of a staining developer to produce a lot of dye. Your under development was likely due to too short development time, and not oxidation of the developer.

[jb7]

lovely image, Jay!

+1 - yes, beautiful-

I'd like to give those cats a go, but I'd imagine that tracking down the chemistry here might be a bit difficult...

Wouldn't the 510 be better for rotary, and in what way would 510 produce a different image to the one you posted, apart (possibly) from the finer grain? Would the stain in the highlights be similar?

[Jay DeFehr]

Hi Joseph, and thank you!

Yes, 510 would be better for rotary. The image produced by 510-Pyro wouldn't be different in any way you could see in a small jpeg. For high resolution work, the HII/ intermittent agitation neg would be noticeably sharper. Stain and grain are comparable.

[Gem Singer]

Jay,

After development, the Pyrocat-HD poured out of the Jobo Drum looking like strong coffee.

I've never experienced that developer turning dark brown when dip-and-dunk developing HP-5+ film on stainless steel hangers in tanks.

Seven minutes of continuous agitation at 70F in 1:1:100 Pyrocat-HD is ample time to yield an HP-5+ negative suitable for scanning.

For dip-and dunk processing, I develop HP-5+ at 70F, in Pyrocat-HD, 1:1:100, for 9 1/2 minutes, agitating for 15 sec, at 2 minute intervals.

[Jay DeFehr]

Gem,

I don't doubt for a moment the developer was very dark, and much darker than your D&D developer, but don't confuse dark developer with exhausted developer. PHD 1:1:100 will continue to increase contrast with continuous agitation for something like 16 minutes, maybe more. It might be the difference in contrast between D&D and rotary is not as great as you estimate, and you simply need to develop your rotary negs a little longer. When the developer truly begins to exhaust, you'll see increased general stain. How much general stain you're willing to tolerate probably depends on your printing process, and D&D might suit you better than rotary processing.

[Gem Singer]

Jay,

The Jobo outfit belonged to a fellow photographer who brought it to my home darkroom in order to try it with Pyrocat-HD.

Personally, I prefer D&D, using intermittent agitation on hangers in tanks.

See my article on the home page of this website: "Developing 4x5 Sheet Film, An Alternative Method".

[Jay DeFehr]

Gem,

I've read your article before, and just finished reading it again. I actually have the SS water-jacketed tank line you used in your University days. I've tried just about every method of developing film I've heard of, or thought of, and have been able to get good results from most of them. There are trade-offs and compromises in development methods and apparatus, just like everything else. For even development, some forms of continuous agitation are unsurpassed (rotary is my third favorite form of continuous agitation, after brush and inversion), but for overall image quality, I think intermittent agitation is king, so I'm working on a system for daylight intermittent agitation development using low solution volumes. I should begin testing this week.

[Gem Singer]

Looking forward to seeing your daylight intermittent agitation process, Jay.

Let us know how it turns out.

[sanking]

Hi!

I'm considering using Pyrocat HD in my Jobo Rotary Expert drum system, and wonder if I can achieve high acutanse with continous agitation with this developer? I have seen some pyro negatives which are extremely sharp and wonders if the same is possible with this combination? Does Pyrocat-HD gives greater edge effect than e.g. Xtol in Jobo rotary drums?

Thanks
The thread has wandered a lot so I will go back to the first question to shorten my comments.

Pyrocat-HD/ -MC used with continuous agitation (as in Jobo or BTZS type tubes) is an acutance developer. In a Jobo I don't believe it would give greater edge effects than Xtol, or other general purpose developers, though exactly what you get with most developers will vary a bit with dilution. In a tray with intermittent agitation both HD and MC are high acutance developers, with even greater acutance with very reduced agitation. If you use either HD or MC as a two-bath developer, as might be appropriate with scenes of very high contrast, acutance is extremely high, and as we would expect, grain also is more pronounced.

There are subtle differences between MC and HD but both are general purpose developers that give good results with either continuous agitation, reduced agitation, or with two-bath development.

Sandy

[wiggywag]

The thread has wandered a lot so I will go back to the first question to shorten my comments.

Pyrocat-HD/ -MC used with continuous agitation (as in Jobo or BTZS type tubes) is an acutance developer. In a Jobo I don't believe it would give greater edge effects than Xtol, or other general purpose developers, though exactly what you get with most developers will vary a bit with dilution. In a tray with intermittent agitation both HD and MC are high acutance developers, with even greater acutance with very reduced agitation. If you use either HD or MC as a two-bath developer, as might be appropriate with scenes of very high contrast, acutance is extremely high, and as we would expect, grain also is more pronounced.

There are subtle differences between MC and HD but both are general purpose developers that give good results with either continuous agitation, reduced agitation, or with two-bath development.

Sandy

The way I understand you Sandy, I could go with MC or HD with continuos agitation, the difference are very small? Im in Europe and can easily get the Pyrocat HD as a kit from Lotus view camera. Some other place in the forum you suggest MC for sheet film with continous agitation. Is it worth the effort to get that instead?

[sanking]

The way I understand you Sandy, I could go with MC or HD with continuos agitation, the difference are very small? Im in Europe and can easily get the Pyrocat HD as a kit from Lotus view camera. Some other place in the forum you suggest MC for sheet film with continous agitation. Is it worth the effort to get that instead?

Correct, the differences between Pyrocat-MC and Pyrocat-HD are very small. MC gives slightly more acutance than HD with continuous agitation but I don't believe one would notice the difference unless they tested the two with a specific film and printing method.

Sandy

[don mishler]

Sandy

I am interested in trying Pyrocat in my Jobo (4x5, 5x7) and as I prefer a liquid developer I was thinking Pyrocat-HD rather than the MC. my question is that since Photographers' Formulary list it two ways Pyrocat-HD ar Pyrocat-HD in glycol, which is more appropriate for my purposes (fiber VC prints) and what is the difference?

[bluejeh]

Hi Jay,
In message #17 (20 September 2011) of this thread you mentioned "I'm working on a system for daylight intermittent agitation development using low solution volumes. I should begin testing this week."
Have you completed your testing and do you have some results to share?
I would like to try Hypercat II (a new developer for me) with your new intermittent agitation procedure, if possible. Thanks.

[Jay DeFehr]

Hello bluejeh,

I've built one tank, but not tested yet. I'll try to get started with testing this week. Whatever the results of my testing, I have no plans to make the system commercially available. If the results from testing warrant further development, the most I'm likely to do in the way of providing the system, would be to post plans at Thingiverse (http://www.thingiverse.com/), for printing with 3DP. In short, if you're expecting a product to come from this, you might be waiting a long time. I'm flattered by your interest, and I'll certainly pass along whatever I learn, but you shouldn't see my tinkering as a product on the horizon. Thanks again, and I'll post here soon with preliminary results.

[Jay DeFehr]

bluejeh,

I just ran the first sheet through the tank, and the results are encouraging enough to keep me working on it. I developed a 4x5 sheet of Fomapan 100 in 35ml of 510-Pyro 1:100 (0.3ml concentrate), for 6 minutes with 10 seconds agitation/ minute. Agitation is by displacement; a squeeze bulb forces the solution out of the tank into a reservoir, and then back into the tank when the bulb is released. Aside from a few tiny air bubbles in the center of the sheet, all went well. Still, a few air bubbles in the center of the sheet is unacceptable. A few raps of the tank might dislodge any clinging bubbles, or a pre-wash might prevent them. The slot is very narrow, and these kinds of bubbles were my greatest concern, along with the possibility the sheet might stick to the inside of the tank. I'll keep at it, as I find the time, and keep you posted.