Tube size for Pyrocat with Extreme Minimal Agitation

[YOU1217]

Hi all,

I have been developing 4x5 sheets of FP4 souped in highly diluted Pyrocat HD with Extreme Minimal Agitation technique. I built the Steve Sherman's developing tubes with 500ml capacity.

Now, I want to make a tube to develop same FP4 but 8x10 sheet in proper size so that I could apply my personal process time and dilutions of 4x5 directly to 8x10. I assume that how much chemical for how much square inches of film is important with this technique.

If I do a simple math; [4x5 (20 sq inches) with 500ml] equals [8x10 (80 sq inches) with 2000ml]

So I can build 2000ml sized tube for 8x10 then I could develop in same manner as 4x5 sheets, without the whole new developing tests for 8x10.

Does it sounds correct to you folks?

[Alan9940]

I use the same diameter tubes for both 4x5 and 8x10--4 inches. My 8x10 tubes hold about 1,350ml of developer and I've never had any issues with development.

[YOU1217]

Thank you for your info. How much developer can your 4x5 tubes hold?

[Alan9940]

Thank you for your info. How much developer can your 4x5 tubes hold?

575ml

[YOU1217]

Ok, so I am probably overthinking this matter.

It was because Mr.Steve always emphasizes that the adjacency effect is strongly tied with the relationship between developer volume and square inches of film so that I thought it had to be equal rate from 4x5 to 8x10 in order to achieve the same density and zones.

[Alan9940]

I have his video series on EMA and have employed his technique many times, but I don't believe developer volume has anything to do with adjacency effects; rather it has much to do with enough stock developer being present to properly develop the film. For fact, when he first published his EMA course he recommend 3 inch tubes for 4x5. I built several, but after much trial-n-error and e-mail exchanges with Steve we determined that there wasn't enough stock solution in the small volume of working solution in that smaller tube. Hence, his later recommendation to use 4 inch tubing.

The adjacency/edge effects comes about from the long periods of rest between agitation cycles. The developer exhausts quickly in the high density areas of the negative while continuing to work in the lower density areas. This "effect" is sometimes referred to as the Mackie Line. I can't say I fully understood all the technical details inherent here, but I can easily observe it in prints! I will forewarn you, though, that development failure (at least, for me) is not uncommon. I believe it's because you're working right at the edge of what Pyrocat-HD is capable of, but it seems that using fresh chemistry might mitigate this problem. Simply through experience, I only use both Part A and Part B for 6 months, then it's tossed out and I mix new.

I will add, too, other development techniques with Pyrocat-HD will produce edge effects. For example, minimal agitation of 2 - 3 min cycles reveals these desirable edge effects at the normal dilution of 1:1:100. As a matter of fact, one of my favorite films in Pyrocat-HD at normal dilution, using a minimal agitation scheme, is Fomapan 100. I process 8x10 using tanks/hangers for 15 mins at 70F, continuous agitation for the first minute, followed by 2 agitation cycles at 10.5, 7, and 3.5 minutes. Results: lovely, sharp, easily printed negatives.

[YOU1217]

It is so nice of you to share your experiences.

It is really good to know that I should just have to have enough developer for each film regardless of their sizes, though I would be willing to build a bit bigger 4x5 tube. Since 4" tube is hard to come by here in NYC, I will probably make 3" tube taller to accommodate at least 575ml like yours.

My dilution has been around 1.5A + 1B + 275 and my aim is a good negative for VC paper by hitting 0.90 to 1.00 density of Zone VIII (with B&W densitometer as Mr.Steve suggested). Even with fresh chemicals, I couldn't get rid of some weird white spots, streaks or mottling at first so that I had to change my initial agitation from 1min to 2min as well as from rolling tube agitation to vigorous inversion agitation. It perhaps is irrelevant but more developer in tube might solve those unevenness. I will also be aware of Pyrocat's shelf life as you advised.

My main film before I discovered Pyrocat was TXP 320. The reason why I switched to FP4 is that I just needed a film that is available in 8x10 with reasonable price (I can never imagine myself could afford 8x10 version of TXP). Fomapan 100 was on my list too with its appealing price but I have had quite quality control issues with 135 and 120 sizes before. Your experience with sheet version made me want to try them again though.

[Alan9940]

Yeah, the only issue I see with a taller 3" tube is getting your fingers down into it far enough to grab the film. I suppose to could push it down just far enough to clear the cap, but, then, if it moves down the tube from agitation cycles you could be in trouble. Not saying it will, but I have had 8x10 film move in BTZS tubes years ago.

My dilution for 4x5 is 3A + 2B + 600ml of water, of which is use 575ml. For 8x10, it's 8A + 5B + water to bring total volume to 1,350ml. This is for Fomapan 100.

I shot a ton of Tri-X 320 back in the day when I could get a 50 sheet box of 8x10 for about $50! Nowadays, LF Trix-X is just too rich for my budget. Btw, before COVID-19 changed the world I used to buy 8x10 Fomapan 100 from fotoimpex (Germany) for about 135 euro, including shipping. Even with the exchange rate to US dollars it was a tremendous deal per sheet. However, nowadays DHL is charging a surcharge to delivery to the USA which has made the total cost too much for me. Anyway, don't know about the QC in the smaller formats as I've only ever shot it in 4x5 and 8x10, and I've never had a single issue.

[YOU1217]

I was doing a math to make 4 inch tube version after reading your suggestion and it is a bit puzzling me.

The area of 4" diameter is 81 sq cm. If you put 4x5 horizontally and fill developer high enough to cover the 4 inch side of film, it's 10.16cm height. 81 sq cm multiplied by 10.16cm equals 822ml. So it leads me that with 4" tube, I need 822ml to at least cover the sheet (if vertical position, 1028ml). Am I missing some?

How much is the minimum amount of Pyrocat that you and Mr.Steve discovered?

[Alan9940]

Don't know about the math, but I just measured one of my 4" tanks, if it helps...

The tank is 16cm tall (including the end cap) and with a sheet of 4x5 film inserted with long edge down it's 56mm from the top edge of the tank to the upper edge of the film. Filled with 525ml of water, it's ~47mm from the top edge of the tank to the water line; about 113mm of total solution depth. A sheet of 4x5 film, inserted horizontally, is about 101mm tall leaving about 12mm of solution depth above the top edge of the film. My stopper for sealing the open end of the tube is about 34mm in height which means I have about 13mm of air space which I think is helpful in providing a more random flow during agitation cycles. I hope this description makes sense.

[YOU1217]

Alan,

Thank you so much indeed for such a detailed description! So many good tips will definitely help me to build a better tube... To have a bit of space for random flow is very useful for instance. This could be why I had uneven development by rolling agitation. I haven't got anyone who is even interested in simple darkroom processes so I am so glad to learn from someone who is knowledgeable about the things I am passionate about... Thank you again.