Gerald Koch said:One of the problems with color films since their inception is color cross-over causing unnatural color representation. There are two ways to prevent the color couplers from migrating within the emulsion. Kodak used a method where the couplers were located in microscopic resin beads. Agfa used a different method with a long side chain on each molecule which acted as sort of an anchor. Kodak's C-41 films now use a system similar to the Agfa method.
Benzyl alcohol is required for C-22 films to penetrate into the resin beads so that the color developer and the color couplers can react to form dyes. Without this chemical you would not get any colors. Therefore, you cannot develop C-22 films in C-41 chemistry.
htmlguru4242 said:Hmm ... Ifigured it would be different.
The temperature problem wouldn't be a major problem, as its easier to process at 75F than it is at 100, less temperature control stuff...
And ferricyanide bleach isn't terribly difficult or expensive to make.
I was looking around online, and it seems that RA-4 chemistry uses CD-3, though there's no mention of benzyl alcohol (though I couldn't find any specific formulas). Perhaps modified RA-4 dev. with ferricyanide bleach, at 75f would work?
Perhaps my choice of the term "resin beads" was not accurate although I have seen this term used before. A text that it consulted refers to "oily droplets".Photo Engineer said:Gerald, sorry, this is wrong.
Kodak and Agfa both used side chains from the start. The side chains on Kodak couplers were nonionic but the Agfa side chains were ionic (sulfonic acids or carboxylic acids).
Kodak couplers were dissolved in organic solvents, while the Agfa couplers were dissolved in mild alkali and then placed directly into the gelatin. As a result, the Agfa couplers tended to thicken the gelatin and make coating more difficult. Therefore, in the mid 70s, Agfa, Fuji and Konishiroku (all users of the Agfa method btw) converted to the Kodak method of long chain non-ionic couplers in organic solvents.
PE
Actually not, always interested in new information.Photo Engineer said:More than you ever wanted to know. Right?
PE
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