Thanks to the inspiration of Jack I did what I have in mind since some time: creating a Diafine clone from raw chemicals. Jack had a question on the Lomad developer from the ascorbate-developers-blog and I read the blog entry and wasn't convinced 100 %. See here:
http://www.filmwasters.com/forum/index.php?topic=6495.0Small sample images with almost low validity and one obscure ingredient. If you do a google search you almost find nothing, except some great cars. The idea of replacing hydroquinone (HQ) with ascorbate is not far to seek, but I prefer the much more common Vitamin-C. Long ago Steve Anchell published in his darkroom cookbook a "real" Diafine clone with HQ. HQ is almost impossible to get here and now. So I took this recipe as a base and substituted the HQ with Vitamin-C and washing soda. Also the Borax I replaced with washing soda. So here's V1.0 of the developer. Working title:
Phenidone-Vitamin-
C-
2-
Bath-developer,
PC2B-V1.0
Part A
vitamin-C 15 g/l
washing soda waterfree 7,5 g/l
sodium sulfite 35 g/l
potassium metabisulfite 6 g/l
phenidon 0.3 g/l
pH: 6.8
Part B
washing soda waterfree 20 g/l
sodium sulfite 65 g/l
pH: about 11
Use destilled water, add in given order, let stand over night before using. Develop 3+3 to 4+4 minutes as a starting point. Very gentle agitation only 2 times in each bath.
Other than often claimed there is already development in the first bath, and it can't be the Vit-C because it needs a much higher pH to be activated. There is some base fog and the development is very low in contrast. Also some uneven development can be seen sometimes. So we need an anti-fogging agent/restrainer. I have pot. bromide and benzotriazole and will probably start with bromide KBr like the Lomad developer.
There's a lot to improve. Shadow detail is great, even for EI 1200, but the density (above base fog) curve is too flat. Base fog is not shown here but too much, about D=0.5. More Phenidone and a restrainer may be the cure. So let's see what happens......
The blue curve is only for reference, the green and the red one are the right ones from 2 different measurings at EI 640. The real picture is taken at EI 800. Quite strong backlight with no exposure compensation, 1/1000 and f/16, so I rate the exposure at EI 1200. Grain vs film speed is very good. Scanning the neg whitewashes the weak points, the neg is rather flat for wet prints.
Best - Reinhold
bigger size:
http://www.flickr.com/photos/imagesfrugales/9655752209/#sizes/o/in/photostream/