Exposing/developing for Azo/Platinum
Hello- I will be making my first attemp at Azo and Platinum and do have a couple questions.
1.) Is there a general number of stops to over expose the negative?
2.) Percentage of over-development, if neccessary?
3.) Will the negative work with both processes? I understand both prefer a dense negative.
I will be experimenting with Efke 100 4x5 sheet film and Pyro developer.
Not that you couldn't get the answers here but these topics (and much more) are fully detailed on the Azo forum. Check it out and you will see a vast amount of information. Good luck with it.
Originally Posted by ImageMakers
There continues to be a misconception about the negative characteristics required for an Azo negative. In response to your questions:
1. You don't need to over expose a negative for use with Azo...in fact it may prove counterproductive since it may very well reduce the density range that the negative will exhibit. Depending on the subject matter and the inherent scene contrast you may actually effectively underexpose because the EI of the film is not a fixed factor. The EI will actually increase with increased development.
2. Yes you do need to increase development...How much? depends on the film and a number of other factors including developer, and method of development...the best thing to do is do the testing yourself.
3. Yes the negative will work with both processes...but again I reiterate...Azo does not require a dense negative it does instead require a negative with a high density range...or contrast. Typically this will be on the order of 1.65 for grade two Azo. This is not a Zone VIII density measurement. It is instead a measurement where the low value density is subtracted from the high value density.
Thanks for the input. I will most likely shoot the same scene multiple times, then develop each different and see the results and take it from there.
In my process I use tube development with minimal agitation using Pyrocat HD at 1-1-150 dilution. For Efke PL 100, the times for SBR 5 1/2 are 60 minutes. For SBR 6 is 47 minutes. For SBR 7 is 38 minutes.
Tray development at 2-2-100 with Pyrocat HD would be different.
Development with rotary development would be different again.
Development with ABC Pyro could be different again.
I would not be prone to recommend a given time without knowing the developer choice and the agitation procedure. That would not be an intellilgent thing to do.
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And the given subject contrast. Where I live is semi desertic, I develop TMY in tubes for 4 min in pyrocat HD 2:2:100 at 76 ºF for a subject with a measured SBR of 11.
Originally Posted by Donald Miller
4 minutes? that's great. I'm using trays & see times around 12-17 minutes. I can't stand it. I'd love to get it down to 4 minutes. Maybe I should pull the tubes back out, increase the temp & give it another go. 4 minutes of spinning tubes sounds a heck of a lot better than 17 shuffling sheets.
Dont get too exited, my developing times for SBR of 4 is 22 minutes..... I agree, it is the pits to stand there rolling for this long.
Originally Posted by matt miller
Great info so far, much appreciated. I checked B&H's website and see multiple choices for Pyro. Can someone recommend which to start with? I will be tray processing first, then setting up a Jobo later.
Thanks - Jim
After trying PMK, ABC and finally Pyrocat, save yourself some trouble and just use Pyrocat with tubes. You will have great results and the lights can stay on for most of the time.
I've used it with Efke 25 and Efke 100 and am pleased with results. tim