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Photography Question 
Laurie P. Voisin

color processing for film and print

I have a small darkroom in my home and i've been doing black and white film and paper processing, but now I want to get into the color processing but don't know where to start. What are the chemicals needed to to film and print processing. Can I get a list of supplies I will need .

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11/28/2006 7:31:30 AM

Alan N. Marcus   Hi Laurie,
For more than 55 years I have been developing and printing color films (each and every process). I can tell you that its both fun and drudgery. I think it’s good for young folks to learn something about the good old days. I once made Daguerreotype’s from scratch, just for the experience. I firmly believe the chemical side of film and paper processing will be history in a few short years. I know this because the manufacturing of films, papers, and developing apparatus will no longer be cost effective. These are businesses where economy of scale keep prices affordable. Stated another way; no matter how good and how advantages films are, demand will soon drop to unsupportable levels. Manufactures will be forced to phase out all production. Yes some diehards will continue but the costs will be prohibitive. My advice is to concentrate on a color digital darkroom (computer setup).

That being said:
Color negative film:
The process is known as C-41. (Kodak Color Negative Process 41 (variations exist).
Kits are available at your local camera store.
Processing is an adjunct of the typical black&white.
Temperature and timing and agitation are more critical.
Steps are:
Color developer (combination b&w developer + color developer)
Bleach (not really a bleach uses EDTA to convert silver to silver salts)
Fixer (same fixer as b&w process solvent for silver salts)
Wash (running water rinse removers residual chemicals often skipped)
Stabilizer (neutralizes residual chemicals, preserves the dyes by immobilizing them + adds biocide to preserve gelatin)
You can’t maintain day-to-day tight control unless you put in extensive effort. Cost to develop film at the local one-hour shop is minimal and control is 1000% better than the occasional lab worker can muster.

Printing requires a color enlarger with adjustable cyan – magenta – yellow filter system or a complete set of color printing (CC filter again magenta –yellow cyan not normally needed for this subtractive system. It is possible to print via the additive using only three filters red – green- blue. Additive system is somewhat more difficult as it involves three sequential exposures. Color balance is achieved by adjusting the three exposure times or apertures used. A color printing enlarger exposure meter is a must if you continue past the curiosity stage.

Processing the exposed paper is again an appendage of the b&w process. You work in total darkness using time and temperature as the safe-lights are mostly unrewarding. The processing chemicals are available at a specialty camera store. The process is RA-4 (Rapid Access Kodak Process 4). Variations exits within the available kits.
Steps are:
Color developer (combination b&w developer + color developer)
Beach-Fix (EDTA and Fixer combined)
Stabilizer (preserves the dyes by immobilizing them) Iif archrival not required you can substitute running water (not advised)

Good for you,

Alan Marcus

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11/28/2006 9:17:17 AM

Mark Feldstein
BetterPhoto Member Since: 3/17/2005
  It used to be that Kodak was the primary supplier of color processing chemicals to the industry. No longer, I guess but they still make E-6 and other kits for doing color neg and transparency films. Here's a link to some of their publications that should help get you started.

Also, if you don't find what you're looking for on their list, call their tech support number and ask them for what you need or may need. There's a book you might find handy too, probably published by Silver Pixel Press nowadays, called "Kodak Professional Color Darkroom Handbook" or something like that which runs about $30 and has all sorts of useful info, tables, processing times, color wheels for correction values, etc.

Lastly, for now, take a look at the web site and think about joining up over there. It's the Analog Photographers Use Group, specializing in film processing, should be a bunch of info on color processing as well although most of the guys there shoot b&w. But someone there should be able to steer you in a good direction as well.
Take it light. ;>)

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11/28/2006 9:19:50 AM

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