Finally done with PMK. What next?

[Gary L. Quay]

Did you get on OK with 510-PYRO?

Have you considered OBSIDIAN AQUA?

They are the only developers I use now. I've got all sorts of other stuff, including HC 110, just rotting in the bottles but the results, for me, from both 510-PYRO and OBSIDIAN AQUA are so very good that I won't be going back to the others just to save them from being wasted. The images are too important to me.

RR

I've used 510 Pyro, and I've never had the mottling problems with it. I may try Obsidian Aqua. Who knows? I haven't had the time to do the testing required to use either. I've always relied on manufacturers' data or the Massive Development Chart for times, and those developers don't show up much. I'm not ruling them out.

[Gary L. Quay]

Pyro oxidizes rapidly, causing mottling and lots of fog. If the gutter of your sheet is not clear then this is a good indication that there is too much oxidation in your process.

Another thought is that your mottling is the result of rapid emulsion swelling. Have you tried using a pinch of sodium metaborate in your pre-wash?

I worried that this was the problem. The last few negatives I processed never left the soup. I moved them around rapidly in the Liquid. I don't think I had any issues with those negs. I haven't tried the sodium metaborate. Do you use distiller water for your presoak?

[frotog]

Yes, distilled water pre-wash is essential. Try a pinch of the metaborate and a longer (say 3-5') prewash. Also, PMK needs frequent, strong agitation. If you are experiencing mottling you are absolutely correct in limiting exposure of sheet to air. Given your predilection for tray developing you might want to invest in a slosher and a deep-wall tray. Despite the huge oxidation of the developer, this will allow for vigorous agitation and free you from having to handle the film once it's wet.

I worried that this was the problem. The last few negatives I processed never left the soup. I moved them around rapidly in the Liquid. I don't think I had any issues with those negs. I haven't tried the sodium metaborate. Do you use distiller water for your presoak?

[Regular Rod]

I've used 510 Pyro, and I've never had the mottling problems with it. I may try Obsidian Aqua. Who knows? I haven't had the time to do the testing required to use either. I've always relied on manufacturers' data or the Massive Development Chart for times, and those developers don't show up much. I'm not ruling them out.

Would you like to have my routine for both developers?

RR

[Drew Wiley]

Any kind of tray development needs a very regular,even, consistent smooth kind of motion to it. It help to have oversized trays, and I personally use dimpled-bottom ones. You need a good pre-soak. The stop bath should not be excessively acidic (even 1% is more than enough to do the job), and you can even use a tray of plain water between the stop and fix to remove the acidity, if the emulsion swells so quickly in the fix that there is a kind of "shock" to it which makes sheets stick together. The same kind of thing can happen in the developer if the pre-soak is insufficient. And it might be helpful to try just a few sheets at a time, like maybe 4, until your technique works smoothly. This is advice I would give relative to ANY developer, not just PMK. And I'd take any generic time chart, like the Massive Dev one, with a grain of salt.... might be OK as a starting point, but you still have to work out your own parameters. Distilled water helps, but you might also need to have a decent water filter on your wash line. Tap water quality varies widely from location to location. PMK is not overtly sensitive in this respect, but you still have to be particularly conscious of things like iron particles getting into the water from old plumbing lines, which will cause a visible problem.
You might also just do an experiment with already processed sheets film that you might otherwise throw away, with the room lights on, so you can see if your
agitation or shuffling technique has air bells trapped for any significant length of time against the emulsion side. Practice with the lights on until you've nailed down
your technique.

[Kirk Gittings]

That was truly a defining event to me as well. The incident meter was a breakthrough. Now I take out the spot meter only on special occasions. Came at a critical time as sheet film prices particularly in the ULF formats dictate as close to perfect results as humanly possible.

Can you explain this more Michael? I haven't used an incident meter since 1978, when I finally "got" the ZS and moved on to a Pentax spot meter.

[Drew Wiley]

A defining event for me was getting rid of incident meters forever, and TTL metering too. Once I standardized on spotmeters, I've never looked back.

[bigdog]

D76 ...: The standard.

There's a reason for that ...

[Drew Wiley]

Not everyone is content driving a Buick.

[Gary L. Quay]

Would you like to have my routine for both developers?

RR

Yes, please.

--Gary