PMK verses Pyrocat-HD

[lee]

guys,

let me ask alex hawley as he has more experience with this developer than I do.

lee\c

 

[lee]

gentlemen, here is Alex's reply to the question. It follows along with my experience also.

Alex Hawley sent this in a PM "Probably won't get to today; I'm squeezing this off at work and I have a dinner to go to tonight.

But, in essence, leaving out the pyrogallol does not affect contrast. In fact, catechol is known for producing higher contrast. The biggest effects I've seen in leaving out the pyrogallol is (1) It becomes a neutral-tone developer vice a very warm-tone developer, and (2) Tray life is much longer. Pyrogallol oxidizes quickly. I've had solutions using catechol only stay active for two weeks if bottled between printing sessions.

Lee, please go ahead and post this in the thread if you like.

Alex

also yes the citric acid improves the keeping properties also.

lee\c

 

[gainer]

In order not to hurt anyone's feelings, I decided to try both Pyrocat MC and a Glycol version of PMK, using the same general recipe for both except. In order to give them equal attention, I used them in equal quantities...in the same developer. No, I haven't been imbibing the spirits. My thought was that it might broaden the spectrum of the stain color to make things interesting. Of course, this means using the same second bath for both, which cold be a mixture of carbonate and metaborate, but my first effort used only the carbonate. So, for the working solution I took 1 part of the pyrocat, one part of the PMK , 2 parts of the Pyrocat B, and 100 parts of water. It did a fine job in 8 minutes at 70F.

Trouble is, I can't tell whether or not it was ruined for the various tasks each creator assigned to the individual soup. There is copious stain, but anyone over the age of 80 is not qualified to be a visual judge of its spectral content. All I can say is that on FP4+ it gave quite fine grain even enlarged from 35 mm to 11X14, but that is not unusual. The -1 stop and +1 stop exposures were acceptable. Maybe someone else would be kind enough to try this test. If you have PMK stock in water, you could use thatalong with the Pyrocat in either water or glycol.

Next I will try tempering the activity by mixing the B solutions as well.

 

[juan]

That's part of what I love about this site. Have a fuss over which of two developers is better, then mix the two together to create a third thing to fuss over. And maybe come up with the Holy Grail of developers. I'm awaiting the results of further tests.
juan

 

[PhotoJim]

I don't think there's much to debate here.

I love PMK.
I haven't used Pyrocat-HD much but it seems pretty interesting. Lots of people love it.

Isn't it nice to have choices?

After all, we could be stuck with D-76... not that it's bad or anything, but what if it were the only developer we could use? I suppose we could have long threads about whether 1+0, 1+1 or 1+3 is the best way to use it.

 

[gainer]

You betcha. I have not done the kind of printing that Sandy King and others here have not only done, but improved. I have seen the advantages of combining a staining developer whose stain color is related to one of the colors used in VC printing. I see no harm in extending the spectrum of that stain color. Of course, extending it too much will make it gray, but I don't think that is within the reach of the hydroxybenzene agents.

A small amount of constant magenta filtration can act as compensation to increase contrast in shadows without much effect in highlights. The magenta overcomes the yellow green stain in the deepest shadows, equals it at some point on the characteristic curve, and is overcome in the densest parts of the curve. This is not a simple density function, but at each point along the curve the contrast of the paper is changing. It's not a simple thing to calculate by hand, but the negative and paper can do it.

It would be interesting to see the effect of combining all three, pyrogallol, catechol and hydroquinone in the same developer.