Darkroom/C-41RA Film Development
C-41RA is a rapid, three-bath process for developing ordinary C-41 colour negative film. It comes as a kit; popular brands are Tetenal and Arista, and they're often called press kits because newspaper photographers used to use them. C-41RA chemistry is a lot like B&W in use, except that it doesn't last as long, hates oxygen, and needs accurate temperature control to work well. The chemistry only lasts about three weeks once mixed, and I get about twenty 135-36 filmsworth out of a one litre Tetenal press kit.
All C-41 film needs the same development, so there's no complicated film-specific developer time matrix of doom.
Important Safety Tips
C-41RA blix is toxic and nasty; don't get it on your hands, clothes, or in your eyes or mouth. The developer's pretty unpleasant too, but the blix is a special kind of assholish chemical. All three of the major components are probably carcinogenic, so yeah, you might want to wear gloves when handling them. You'd be a special kind of jerk to leave it, or things that have touched it, where people might be handling food. Keep chemistry away from food, animals and children.
When your chemistry's spent, dispose of it carefully; the developer is okay to pour down the drain with plenty of water, but the blix has silver compounds in it so needs to be de-silvered before disposal. The stabilizer has hydrazine and (when used) formaldehyde in it. Dispose carefully. Both the blix and the stabilizer will gradually off-gas in the bottle, so don't leave them on the shelf too long unless you want to see the bottle blow its top.
If you get any of these chemicals in your eyes, get someone to force your eye open and flush under running water for several minutes, and then get them to take you directly to the eye hospital. I am not even kidding.
Everything you use in this process needs to be totally free of grease, soap, and other impurities. Colour film is a complicated chemical system that revolves around selectively monkeying with dye molecules, and a couple dabs of soap on your processing drum will totally ruin the developer.
Before You Start
- Make up your chemistry according to the instructions. You'll need three bottles to put it in.
- Mark your bottles: Developer, Blix and Stabilizer. Don't mix them up.
- Make up a tempering bath and heat it to 100.3 degrees Fahrenheit. Or 38 degrees Celsius. It doesn't have to be closer than half a degree or so.
- Put your chemistry bottles in the tempering bath and wait for them to get to temperature.
- Make sure your tank, spiral, and bottles are compatible with colour chemistry, because some plastics aren't. The Paterson tanks are. Glass bottles aren't. No, really.
- In complete darkness, roll your film into a tank.
- Turn on safelight or house lights, as your paranoia permits.
- Fill your tank with water at the process temperature, and let it sit for a minute or two. Agitate it a bit. This, and all following steps save the wash stage, should be done with the tank sitting in the tempering bath.
- Empty the water out; marvel at the funny colour it went.
- Add developer to tank. Knock it on the table, then stand it in the tempering bath. Agitate for the first thirty seconds, then do four inversions every thirty seconds. You'll soup your film for a total of three minutes and thirty seconds.
- Pour developer back into your stock bottle.
- Add blix to tank. Agitate it the same way as the developer, but this time for six and a half minutes.
- As your film is blixing, it will produce a little sulfur dioxide. You will have to burp your tank a couple times.
- Pour the blix back into the bottle. It stinks of ammonia and sulfur dioxide: don't breathe this.
- Immediately rinse with running water at process temperature, for three minutes. (at this point you can take your time and expose the film to light if you need to. or want to.)
- Empty out the wash water, and add stabilizer. Agitate continuously for thirty seconds to a minute.
- Return stabilizer to the bottle.
- You might want to do a very, very quick dunk in photo-flo, to make the film dry more evenly, but it's against the instructions; I always do it anyway.
- Drying and praying against the anti-dust gods. You may also want to use the film dryer.
- Before you put your chemistry away, squirt some Dust-Off into each bottle to displace the oxygen that will destroy the chemistry while you sleep.