Rollo Pyro Questions

[Alan9940]

I've used various pyro formulas for many years in both hand processing and on my Jobo, but I've never used Rollo Pyro. I've read in a thread on this forum (Rollo Pyro Experience) and other places that the sodium metaborate after-bath is pretty much useless. Back when I used PMK, I stopped the after-bath treatment after hearing that Mr. Hutchings no longer recommended it. But, it's interesting that the instructions on both the Bostick & Sullivan and Photo Formulary websites show using the after-bath. Ergo, the following questions:

1) Do you use a sodium metaborate pre-rinse?

2) Do you use a sodium metaborate after-bath?

Thank you for any insight provided.

Alan

[Michael R]

Sodium metaborate pre-bath: not a good idea

Sodium metaborate after-bath: not useful

These are universal (doesn’t matter what developer)

[Mark Sampson]

Hmm. I develop 4x5 sheet film in trays and have long used a 1% Kodalk solution as a pre-developer bath; its main purpose is to keep the sheets of film from sticking to each other when first wet. Can't say that it has any effect on my negatives apart from fewer failures.
I was a PMK user for a long time... following Mr. Hutchings' instructions I used an after-bath but gave that up. It didn't seem necessary.

[Jim Noel]

I found the pre-soak in 1% Kodalk also of little or no use. I have no trouble with film sticking together in the developer if i just delay about 10 seconds between sheets being added to the plain water pre-soak.

[Michael R]

It’s not that the alkaline pre-bath is bad in and of itself. It’s that the emulsion is saturated with an alkaline solution (in the case of Kodalk (metaborate), a relatively high pH with some buffering even at only 1%) before entering the developer. Alkali is the activating component of a developer, so an alkaline pre-bath is effectively modifying the developer. Not necessarily “bad” per se, but not the developer you thought you were using. There is simply no reason to do this. It adds no value versus a plain water pre-bath, and can quite drastically alter the subsequent development step. If you’ve been doing it this way for a long time and know your process, no reason to stop now, but not a good idea to add to any process.

[Alan9940]

Thank you, all, for your input. If I do give Rollo Pyro a try, I'll skip the pre- post-baths.

[Doremus Scudder]

Thank you, all, for your input. If I do give Rollo Pyro a try, I'll skip the pre- post-baths.

You may want a plain water tempering bath with rotary processing. I believe Jobo recommends one. I tray process and always use a presoak to keep sheets from sticking together. My experience with rotary processing is many years hence. Still, I seem to remember that you can get streaks or uneven development from just pouring in the developer without a presoak. Others with more pertinent experience will likely chime in here.

As an aside, the purpose of Rollo Pyro was to slow down the oxidation of the pyro caused by the increased exposure to air caused by the rotary processing. Another way to deal with this is Bob Carnie's method of pouring out the developer halfway through development and replacing it with fresh. I believe he uses PMK.

Best,

Doremus

[Michael R]

Jobo recommends pre-soaking for its rotary processors/tanks.

Kodak has long indicated pre-soaking sheet film *may* improve uniformity, although it isn't really clear if they are referring to tray shuffling (obviously important) specifically or all of the processes they describe. Ilford recommends against pre-soaking its sheet films citing possible uniformity problems but here again it isn't clear which type of processing they are referring to.

It usually can't hurt - as long as it is water, not alkali. Ron (PE) always said he thought it was generally a good idea whenever the film cannot be uniformly wetted.

Unfortunately this all gets rather complicated because there are so many variables involved including the emulsion, and I have found there is no good "theory". What works for someone might not work for someone else etc. etc.


You may want a plain water tempering bath with rotary processing. I believe Jobo recommends one. I tray process and always use a presoak to keep sheets from sticking together. My experience with rotary processing is many years hence. Still, I seem to remember that you can get streaks or uneven development from just pouring in the developer without a presoak. Others with more pertinent experience will likely chime in here.

As an aside, the purpose of Rollo Pyro was to slow down the oxidation of the pyro caused by the increased exposure to air caused by the rotary processing. Another way to deal with this is Bob Carnie's method of pouring out the developer halfway through development and replacing it with fresh. I believe he uses PMK.

Best,

Doremus

[Alan9940]

Thanks, Doremus. I meant that I'd continue on using a plain water pre-rinse and skip the alkali component. I run Jobo Expert Drums for 4x5 and 8x10 and have always used a 5 min pre-rinse. And, I have used Bob's suggestion regarding PMK and it works great!