Issues Attempting Extreme Minimal Agitation Pyrocat HD Development with Ilford HP5+ in SP445 Tank

[Thinh__Le]

This is my first time attempting the EMA development process with Pyrocat HD and I had run into some issues that I need help with.

My process was to develop the HP5+ negatives, which I had rated at 320 for a total time of 45minutes at 68 degrees fahrenheit. Initial 2 minutes of agitation, followed by agitations for 20 seconds every 7min 30 seconds. Water stop bath for 1 minute. Fixed for 5 minutes in TF4. And a final wash for 25 minutes.

There appears to be some burned edges of the SP445 found on the negatives and am curious about it and hope someone here can help me with learning this new development method.

Attached are images.

 

[koraks]

This looks like you have a problem with general stain or just plain old dichroic fog. It's not present along the edges probably due to the geometry of the tank/film holder.

To prevent this, use an acidic stop bath. You can also use an acidic fixer. This is the easiest solution, and rest assured, it will leave the stain alone just fine. The "acid stop/fix will damage the stain" is a very persistent myth - and an unfortunate one, because it can result in trouble as you've presently shown. https://tinker.koraks.nl/photography/to-stain-or-not-to-stain-acid-and-pyro-developers/

Feel free to use a pH neutral or alkaline fixer if you want, but when doing so (esp. an alkaline fixer) it's crucial that you prevent any developer carryover into the fixer bath. A single water stop is courting disaster (as you've aptly demonstrated). If you insist on a pH neutral to alkaline process throughout, perform a couple of water rinses between develop and fix, not just a single water 'stop'.

The fact that you used EMA is likely not really a factor here, although during the long period of development, you will get a high degree of oxidization of the pyrocatechol, which may make matters worse. In general it does result in a higher base stain. This will generally not be a major issue when scanning or enlarging your film; it's inconvenient or even cumbersome when using UV-based contact printing processes.

 

[Thinh__Le]

This looks like you have a problem with general stain or just plain old dichroic fog. It's not present along the edges probably due to the geometry of the tank/film holder.

To prevent this, use an acidic stop bath. You can also use an acidic fixer. This is the easiest solution, and rest assured, it will leave the stain alone just fine. The "acid stop/fix will damage the stain" is a very persistent myth - and an unfortunate one, because it can result in trouble as you've presently shown. https://tinker.koraks.nl/photography/to-stain-or-not-to-stain-acid-and-pyro-developers/

Feel free to use a pH neutral or alkaline fixer if you want, but when doing so (esp. an alkaline fixer) it's crucial that you prevent any developer carryover into the fixer bath. A single water stop is courting disaster (as you've aptly demonstrated). If you insist on a pH neutral to alkaline process throughout, perform a couple of water rinses between develop and fix, not just a single water 'stop'.

The fact that you used EMA is likely not really a factor here, although during the long period of development, you will get a high degree of oxidization of the pyrocatechol, which may make matters worse. In general it does result in a higher base stain. This will generally not be a major issue when scanning or enlarging your film; it's inconvenient or even cumbersome when using UV-based contact printing processes.

Thanks for the tips! I have some Photo Formulary Citric Acid and was wondering how many grams would you suggest for mixing into 1Liter? Also, with the acid stop would you do two baths—say, a 30 second stop followed by another 30 seconds?

 

[koraks]

how many grams

It doesn't really matter; it's entirely non-critical. For a single-use 'one shot' stop bath, something like 0.5% would be fine, i.e. 5g/liter.

with the acid stop would you do two baths—say, a 30 second stop followed by another 30 seconds?

No, with an acid stop, a single bath is OK. With plain water and an alkaline fix, I'd do 2-3 washes between stop and fix. With an acetic fix or a buffered pH neutral fix, one stop or water bath would also be OK.