Lien : http://www.apug.org/forums/forum216/379 ... l-use.htmlTitle: Process ECN-2 for Pictorial Use
Purpose:
To demonstrate that color motion picture film can be used for pictorial use.
To present a variation of process ECN-2 for the creation of still negatives.
Procedure:
ECN-2 negative film can be gotten for very reasonable prices as short ends but there doesn't seem to be any information about using it for pictorial use, except that it probably a bad idea. Further the ones that want to do it seem intent on using C-41 chemicals instead of the ECN-2 chemicals. Thus producing negatives of less than archival quality even though the formulas for process ECN-2 are published.
The color developer was adapted from its original published form to reflect what I had available and what I could get a hold of for instance Kodak Anti-calcium was removed from the formula and antifoggant AF2000 was also removed as I couldn't source these two chemicals. This necessitated the use of distilled water. Also potassium bromide was substituted for sodium bromide as it was easier to obtain and is less expensive. The stop bath made use of acetic acid instead of sulfuric acid, the fixer was Arista Arifix. It also appears that Kodak has removed formaldehyde from all photographic processes including process ECN-2. After careful reading of the MSDS it was concluded that the chemicals in Final Rinse was the same as what was being offered for process ECN-2.
After warming the water to appropriate temperatures the chemicals were mixed as specified in the formulas section.
Temperature control was achieved by the drift by method were the temperature drop during the color developer step was determined then the change in temperature was divided in half and added to the recommended start temperature. In my case I experienced a drop of 7°F so 7°F/2=3.5. Starting temperature is 103.5°F. Developing time was standard C-41 time of 3.5 minuets. Similar C-41 times was used for the stop, bleach, fix and finial rinse with appropriate rinses between stop and bleach, fix and final rinse.
The rem-jet antihaliation backing was not removed until after the end of the process. After the final rinse step a cotton pad like those for the removal of makeup was used to remove the backing quite easily.
Formulas:
COLOR DEVELOPER
Distilled Water 21 to 38°C (70 to 100°F)
850mL
Sodium Sulfite (Anhydrous)
2.0g
Potassium Bromide (Anhydrous)
1.4g
Sodium Carbonate (Anhydrous)
25.6g
Sodium Bicarbonate
2.7g
CD-3
4.0g
Distilled Water to make
1L
STOP
Water
964mL
Acetic Acid 28%
36mL
BLEACH
Distilled Water 32 to 43°C (90 to 110°F)
900mL
Potassium Ferricyanide (Anhydrous)
40.0g
Potassium Bromide (Anhydrous)
29.0g
Distilled Water to make
1L
Results:
The motion picture film used was Kodak 5205 a Vision-2 250 daylight balanced film shot at an EI of 225. The still film used was Fujifilm Super HQ 200. A amature film was used since the film being compared against is being used outside its intended use. The C-41 negatives were developed and printed on a Fuji Frontier at a local Wal-Mart on Crystal Archive paper the ECN-2 Negatives were developed myself and then printed at the local Wal-Mart using the same machine and paper.
These photographs were taken during overcast weather. The Fuji negatives appear to have been exposed on a bright sunny day with the over saturation and blown highlights associated with this film/paper combination. I shudder to think what this would look like on a bright sunny day. The prints from the ECN-2 negatives have less saturation than the Fuji negatives, but that is another way of saying that the ECN-2 negatives have a more accurate color reproduction compared to the Fuji negatives. Also highlights aren't blown as they are in the Fuji negatives.
Conclusion:
ECN-2 films can be used for pictorial purposes and that the ECN-2 process can be adapted for normal darkroom use.
J'ai mis ça ici pour pouvoir le retrouver plus tard
