minor update
After spending hours and hours calibrating my cheap ph meter I figured out that the ph from my former developer solution was about 10.16 .
This was close enough to enable developing really nice negatives,
the Agfa portrait (a misjudged beauty) and the Konica pro 400 came out very well. The Agfa vista 100 seems to be a bit more contrasty as usual, but we are talking about nuances.
Well, well this encourages me to do an other batch, where I will include a carbonate buffer, similar to a Kodak receipt. Hopefully this is safer as plain sulphuric acid and will end in a more stable ph, not so prone by varying water supply. I used more bicarbonate because not using the acid Sodium metabisulfite and increased the Potassium Carbonate again
Here comes my new receipt
Tab water 800 ml
Calgon 2.5g
Potassium carbonate (anhy) 37 g
Sodium Bisarbonate 7 g
Sodium sulfite (anhy) 4.3g
Sodium bromide 1.3 g
Potassium iodide 1.4 mg
Hydroxylaminsulfate 2.4 g
CD-4 4.5 g
The resulted ph I measured is 10.00 (but we will see
) If anyone is able to calculate the pk's values "on the fly" it would be nice to hear about...
The Chemicals are warming up right now, waiting for another run.
I have to go back to the cellar :rolleyes:
The text below is taken from various patents on patentstorm etc. just to show that we are on the track.
Source:
http://www.patentstorm.us/patents/6649331-description.html
This is one of the very rare moments you can read direct the term "C-41" in the receipts, most times only called "as known in the art", "as published in Process C 42 Manual, Januar 1984, Eastman Kodak Company", or the "KODAK C-41 process, as described in the British Journal of Photography Annual of 1988, pp. 196-198" when it comes to numbers which seems to be serious. By the way, if there is anybody out there, who do have access to the C-42 process manual I would be very happy to get a copy of the receipts suggested there
As far Im informed Process C-42 is essentially the same as C-41 but the process manual is designed for labs who mix their chemicals from scratch and include receipts
But back to theme, if you want to follow the original link, scroll down the page, it's all about shortening of the processing time, specifically the color development time.
At the end of the page you find bleach as well fixer receipts.
"The compositions of the developers for the example are shown in Table 2 below. All numbers are concentrations in mol per litre of final solution except for poly(vinylpyrrolidone) which is in grams per litre. The pH of the one litre solution was adjusted to the aim pH with potassium hydroxide or sulfuric acid at 24 C."
Very friendly these mol/L advices, arent they ?? The units for bleach and fixer are in gramm again...
TABLE 2
............................C-41 ... Invention...Invention...Invention
Invention
..........................Formula Formula A Formula B Formula C
Formula D
-----------------------------mol/L mol/L mol/L mol/L
mol/L
hydroxylamine sulfate ---0.012 --- 0.018 ---- 0.018 ---- 0.018
0.018
diethylenetriamine ------- 0.005 --- 0.005 ---- 0.005 ----0.005
0.005
pentaacetic acid, sodium
salt
potassium iodide (×10-6) --7.229 ---1.205 ----1.205----------
1.205 1.205
poly (vinylpyrrolidone)-------------3.000 ----3.000 -------3.000
3.000
(g/L)
sodium bromide----------0.013 -----0.0078 ---0.0243 ---- 0.0466
0.0661
potassium carbonate-----0.271------0.289 -----0.289-----0.289
0.289
4-(N-Ethyl-N-2- -------0.015------0.051-------0.051---- 0.051
0.051
hydroxyethyl)-2-
methylphenylenediamine
sulfate
potassium sulfite ----------------- ---0.084------0.084----0.084
0.084
sodium sulfite-----------0.032
adjusted pH-------------10.07--------10.48------10.48-----10.48
10.48
Okay, here are the concentrations converted via molecular weight to Grams /Litre, now this formulation looks quite familiar.
Water 800.0 mL
Diethylenetriaminepentaacetic acid pentasodium salt (DTPA 5-Na, solid) 2.51 g
Potassium Carbonate, anhydrous 37.45g
Sodium sulfite, anhydrous 4.03 g
Sodium Bromide 1.34 g
Potassium Iodide 1.20 mg
Hydroxylamine sulfate 1.97g
CD-4 4.38 g
Water to make 1.0 L
pH @ 24°C 10.07
Very important seems to be the sentence "the pH of the one litre solution was adjusted to the aim pH with potassium hydroxide or sulfuric acid at 24°C".
These receipt are NOT MEANT to reach the ph of aim without exert influence, and probably this is true for other public receipts too! This will be an explanation for the enhanced contrast Pete, RPC and myself noticed. Whatever you do with the various (similar) homebrew's, watch out for the ph, it is supposed to be around 10.05 and has to forced in this direction !!!
Samples of each of these monochrome coatings were imagewise exposed through a graduated density test object and processed at 100° F. according to a modified C-41 process using the following sequence of processing solutions: development, 3 min 15 sec in KODAK FLEXICOLOR Developer (Developer solution D-1); stop bath, 30 sec; bleach, 3 min in KODAK FLEXICOLOR Bleach II; wash, 3 min; fix, 4 min in KODAK FLEXICOLOR Fix; wash, 3 min; and stabilizer, 30 sec in KODAK PHOTOFLO solution. Developer solution D-1 is described below in Table VII
TABLE VII
______________________________________
Anhydrous potassium carbonate 34.30 g
Anhydrous sodium sulfite 0.38 g
Potassium bicarbonate 2.32 g
Potassium iodide 1.20 mg
Sodium metabisulfite 2.78 g
Sodium bromide 1.31 g
Diethylaminetriaminepentaacetic acid 8.43 g
pentasodium salt (40% solution) (KODAK Anti-calcium No. 8)
Hydroxylamine sulfate (HAS) 2.41 g
KODAK Color Developing Agent CD-4 4.52 g
2-((4-amino-3-methylphenyl)ethylamino)- ethanol sulfate (1:1 salt)
Water to make 1 liter, pH 10.0 ± 0.05 80° F.
Here a Fuji Komposition
The composition of each processing solution was as follows, respectively: (Color-developer) Tank Solution (g) Replenisher (g)
Diethylenetriaminepentaacetic acid 1.0 1.2
1-Hydroxyethylidene-1,1-diphosphonic acid 2.0 2.2
Sodium sulfite 4.0 4.8
Potassium carbonate 30.0 39.0
Potassium bromide 1.4 0.3
Potassium iodide 1.5 mg -
Hydroxylamine sulfate 2.0 3.0
4-(N-ethyl-N-β-hydroxyethylamino-)-2-methylani line sulfonate 4.5 6.0
Water to make 1,000 ml 1,000 ml
pH 10.05 10.15