Please note, an important question was asked about this method that deserves mentioning here:
The questioner, J, asked if the PH would be changed because of the 25ml of propylene glycol I added with the phenidone dissolved in it. This made the amount of TEA in the developer only 75% of its original formulation. It seemed a lot and would change the PH and therefore the qualities of the developer.
Very good question. Here's my answer:
"I did the PH test this morning. The dilution for developing with PC-TEA is normally 1+50 so I chose that as my test dilution, 10ml to 500ml water. I took 500ml distilled water and added just 7.5ml TEA (simulating a 75% solution of TEA in PC-TEA as I made in the video) and stirred well. The measured PH, using an 8100 PH Meter, was 10.08. I then added 2.5ml more TEA making a total of 10ml TEA in the 500ml water and stirred well. This was now the same as a 100% TEA version of PC-TEA as formulated by Pat Gainer. The PH remained at 10.08. This shows me that the buffering PH of the TEA is the same at 75% as 100%. It was a good question you asked and deserved a thorough investigation to check if my thoughts were valid. This is also good info for the other KZitem watchers so thank you for your curiosity!".
Therefore, do not worry that using 25ml of 1% solution of propylene glycol (PG) will change the developer. I didn't test any more dilutions, just the one I demonstrated. If you are nervous about adding this much PG then make a stronger solution if phenidone in PG such as 2%.
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Recently I helped a couple of photographers with a problem with their negatives. They were under developed. We tried a few things but eventually worked out that the phenidone was weaker than it should have been. We also worked out that the heat, when making the developer, had cooked the phenidone. I used to do the same but am now suggesting this alternative. So here are some important tips on making developers like 510-Pyro and Pyrocat in glycol. There's easy mistakes to make that will give you a developer that's less than satisfactory. I'll make some PC-TEA (by Patrick Gainer) and on the way will show how you can improve your developers.
John
www.pictorialplanet.com
Негізгі бет Important Tips on Making Developers like 510-Pyro and PC-TEA
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