Wednesday, May 22, 2013

Trying and trying

I am still gaining control over the paper direct positive process based on the recipe of Donald Qualls for film.
I spent the whole day taking pictures, one after the other, and developing in different conditions. I also used Parodinal again but I found out that my recipe of CSS works much better.
I reduced the amount of CSS in the developer to the half but increased the ammount of soda to the double. It works fine. I also tryed a weaker version with only 1/4 of CSS but it was a disaster. So, more or less, the optimal recipe for the developer is:

50 ml of CSS
200 ml of a sol. of Soda at 10%
250 ml water

Pulling the string linked to shutter
The Bleach is exactly the same of the recipe given by Donald Qualls, i.e., 10g Potassium Dichromate and 12g Sulfuric Acid for 1 liter solution. Also the clearing bath is the same, 10% Sodium Sulfite.

An interesting thing is that I don't need a clock to count the baths durations, all of them require counting from 1 to 100. Only the bath in just water after Sodium Sulfite should be 2-3 minutes.

I would like to use this process for portraits, but my lights are too weak for the paper sensitivity. Now I am thinking of buying panchromatic paper which is maybe more sensitive and I may use indoors with artificial light. Meanwhile, I made a self-portrait at my balcony but even there I needed 1/2 second exposure time at f/5.6.

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