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Saturday, May 18, 2013

Establishing the procedure of direct positive on normal photo paper

As I already said before, I was just trying this recipe of Donald Qualls but using paper instead of film.

With fresh prepared developer baths and bleaching bath, it was not too difficult to get the first results. But the devil is in the details. And so I started a long series of trial and error until I could come to a more confident procedure that gives results if the exposure was correct.

Below is the photo as it comes after the whole procedure until washing and drying, scanned reflexive with my Epson V500. No adjustments in scanner and no adjustments in software.

The picture as it comes
After balance in software
Aplying a daguerrreotype mask
Because the image is inverted like in the daguerreotypes, I played a little in the last picture, making a sort of daguerreotype look with the program Photoscape.

Now, in what consisted the whole procedure, still not the last word, I think, but where we can go with a certain confidence.

The first results I got were developed with a Parodinal I made one year ago. But I spent the last drops of it inthe experience and then, after one day the developer became weak and I had a lot of disasters. At one point I was almost giving up. I changed the dichromate bath with Betadine and also with ferric EDTA but none worked. I decided to start from the beginning but now using as developer my CSS (Caffenol Super Strong) and as bleach bath again potassium dichromate in a higher concentration because I noticed that the zones bleached did develop again. So, resuming we have following recipe:

100 ml of CSS
100 ml of a 10% sol. Sodium Carbonate
300 ml water
50 ml of a solution containing 10% Potassium Dichromate and 13% Sulphuric Acid
450ml water
Clearing bath:
500ml of a 10% sol. Sodium Sulfite
100 ml of a 60% sol. Ammonium Thiosulfate
500 ml water

After exposing the paper in the camera,
Step1: Develop in the developer for about 1 minute, until you see that nothing more happens. You should have a nice negative, rich in contrast.
Rinse in water
Step 3:
Bleach for 1 minute. Although the image vanishes in seconds, prolong the bath until one minute (I just count from 1 to 100 shaking up and down the tray)
Rinse in water
Step 5:
Give a one minute bath in the clearing bath.
Step 6:
Rinse and leave in just water for one minute
Step 7:
Put the paper with the emulsion side up in a tray with just water and expose it to light, I used a 50W lamp at some 50 cm, during 2 minutes. A fancy blueish positive image will appear slowly.
Step 8:
When the image in water is clear to see, change the paper to the developer again and develop for one minute again.
Step 9:
Rinse in water
Step 10:
Fix like usual for 1-3 minutes
Step 11:
Wash well and let dry.


Equipment used: Zeiss-Ikon folding 9x12 camera with a Wollensack 135mm f/4.7; Ilford Multigrade IV paper, brillant.

Last changes, 22-05-2013,

I found out that Parodinal, in the paper concentration, is not a good developer to use because pictures come foggy. The CSS (Caffenol Super Strong) gives excellent results, even less concentrated. I am using now:

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

What the bleach bath is concerned, the concentration is the same of Donald Qualls when used in 1+10 dilution.

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