Homemade C-41, E6 and RA-4 Formulas -- U Tried?
Now that I have the ATL 2300 Jobo plumbed and will be ready to run when I get a new valve kit for my tempering valve (ach, don't ask!), I am exploring self-mixed C-41, E6 and RA-4 chemical formulas.
Oldbikerpete (in an older thread) graciously reprinted the formula for C-41 he was able to compound with help from several APUG members, so I have that and assurance it works fine, but I only have untried RA-4 formulas.
Has anyone ever used the RA-4 formula here?
After getting all the plumbing for the Jobo installed tonight, I reached for my 1 liter Tetenal E6 Kit to read up on the instructions and found it stuck to the shelf. Seems the heat had caused the Color Developer Part 2 foil pouch to rupture inside the sealed clear plastic bag, so I had the rest of the packets swimming in nice black goop and it had leaked out of the clear bag and cemented itself to the shelf! Kiss $30 goodbye...
At least the $45 1 liter C-41 kit was still OK, but it drove home the fact that IF I am going to be processing color on a regular basis, I can't afford to buy these Tetenal or even Unicolor kits, but would have to mix myself from scratch.
Also looking for an E6 formula that uses chemical fogging not bulb exposure...
All comments and observations welcomed...
Last edited by Kino; 08-06-2006 at 11:07 PM. Click to view previous post history.
Reason: bone-headed mistake
Have you priced the individual components for making RA4 and C-41. Seems like I did this a few years ago and though the cost was less it was not enough to justify the hassle of stocking and mixing.
Originally Posted by Kino
Just my 2 cents,
Cheaper, I suspect, than mixing together primative but working process chains for C-41, E-6 or RA-4 I'd look to mini-lab chemicals. Lets focus on the 2/3 bath processes:
Both C-41 and RA-4 are the same neutral rapid fixers. The price of a 5/10 litre of concentrate from a wholesale mini-lab distributor is generally less the price of the ingredients if purchased through a chemical supply house (the raw chemicals get cheaper in significantly larger volumes). Fix is cheap!
Bleach is the most expensive part of the process but it can be re-used and re-used and re-used. BLIX (Bleach-Fix) from the reduced bath kits (typical for amateurs) is more expensive as the fix is quickly used up. Bleach has almost unlimited shelf-life.
Commercial colour developers are not too expensive and well tuned. Its the key to the process and process control is important. Most of the formulas are proprietary. The cost to mix one of the open source developers and the cost to purchase (in quantities of 5/10 litres of concentrate or less) is similar if not even higher. Champion, Calbe and others compete well for the market.
On the price issue. I brew my own C-41 developer and buy everything else. The developer is the bit that keeps the least. Mixing my own isn't that expensive. It would likely be cheaper to buy jugs of C-41 minilab developer but if you have waste then the math changes.
For RA-4 developer life is less of an issue for me. Even if you only develop one roll of 35mm you can easily end up making a bunch of 8x10. That means you use the stuff up. I just mix up small volumes of developer. The stock keeps well enough and the print drums need very little volume.
All published formulas for C41, E6 and RA that I have seen are not exactly correct. Some are better than others. The closest to 'real' are a set of RA solutions that I saw published via a link on Photo Net. The furthest away have been all of the E6 formulas I have ever seen published.
Errors in developer formulation will cause crossover, color shifts, speed changes and in the case of films, worse grain and sharpness.
If you use CD4 for color print materials as some formulas do, you will get a severe loss in dye stability. This may not show up for years.
Errors in bleach, fix and blix will have fewer consequences, but many of the solutions contain proprietary ingredients only available from Kodak and Fuji.
I used to mix my own routinely, but it was a pain (and part of my job in the lab).
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I've used both mix-it-yourself and commercial chemistry. Concerning costs, the mix-it-yourself approach can result in cost savings, but only if you use relatively modest quantities; for low-volume users, you're looking at inflated per-roll or per-sheet costs from buying small-quantity packages and/or developer going bad because it sits on the shelf for too long. The mix-it-yourself approach, OTOH, enables you to mix whatever quantity you want, so there'll be less waste, and the dry chemicals keep for a long time compared to the solutions. Most of the cost savings is likely to be in the developer, both just looking at the raw numbers without considering waste and because the developer will go bad quicker than the other chemicals.
Another cost issue is kits vs. individual components. You'll almost certainly pay less if you buy individual components than if you buy a kit. Unfortunately, this complicates buying the stuff, but it's definitely worth looking into the individual components.
Concerning the RA-4 formula to which you referred, I've used it, but I've not done any side-by-side comparisons with the results from commercial developers. To my eye, though, I'm satisfied with the color from this developer when I've used Kodak, Fuji, or Agfa paper. I've had problems with some Konica-Minolta paper I bought off of eBay, though; unexposed parts of the paper turned out a bit yellow. I could reduce this by underdeveloping a bit, but this required filtration changes and made the colors a bit weak. I suspect the paper was simply old or had been improperly stored; as I said, I bought it from a private seller via eBay. It's also possible that adding the Tonopal SFP would improve matters, but I don't have any to test this hypothesis. FWIW, I did these tests with the room-temperature variant of the formula (with potassium hydroxide). Whatever the cause, the commercial developers I've tried with the Konica-Minolta paper (Paterson and Tetenal) both produce better results. For other papers, I'm happy with that developer -- although again, I've not done any side-by-side comparisons.
I've not used the C-41 formula described on the same page, but I have used NCF-41. My conclusion is that it's not reliable enough. At its best, it produces negatives that are, to my eye, good, and that print or scan well. At its worst, it produces thin negatives that seem overly grainy. For some reason, NCF-41 is worst with Ilford XP2 Super. I may try the formula on the page you mention in the future, but for now I've got a bottle and a half of Paterson Photocolor II left, so I'm using that.
Is the Bleach the same for both?
Originally Posted by edz
Any particular reason for not wanting to use a fogging re-exposure? I have found it to be easier and more reliable than using a chemical foggant. I don't know what Kodak uses now but the E-6 foggant some years ago was a substituted borane which was quite toxic and not something that you wanted to get loose in your darkroom.
Originally Posted by Kino
No. The mini-lab bleaches are "similar" but the C-41 is a bit different. One could probably make a dual C-41/RA-4 bleach around Potassium Ferrocyanide. It would, of course, not be suitable to BLIXing.
Originally Posted by fotch
The three processes use 3 different oxidants in their bleach baths. It is not wise to use a blix for film, as they usually are too weak or are too short lived. Only papers are safe with a blix.
Originally Posted by edz
Do not use Ferrocyanide with color, use Ferricyanide. Also, this strong oxidant has not been tested with current couplers or dyes in color products and so, even though it was used at one time, it is untested now, and the restults on the film or paper is unkown. I suspect that the results will be OK though.