I am considering purchasing a Jobo CPE-2+, and I am trying to estimate the C-41 chemical costs. The main reason, I want to process my own film is that it sounds like fun. However, I am confused about reusing the Bleach.
Assuming I purchase the 1 gallon Kodak Flexicolor kit, and I use the Jobo Tank 1510 with a single 35mm reel, the tank requires 140 ml of chemistry as listed on the Jobo site. Therefore, I should be able to process (27) rolls of film or 3.8 l / .140 l.
On the Kodak Flexicolor site, they specifically address rototary processors in the following file. http://www.kodak.com/global/plugins/...ls/z131_03.pdf
Kodak says the bleach can be reused, and the maximum number of 400 ASA rolls should be (28) or twice the "sink-line" developer rate of (14) -- see table 3-3.
The obvious answer is -- Don't re-use the bleach. However, the bleach is the most expensive chemical, and reusing it will drop the cost per roll.
Does anyone reuse the bleach, and if so, how often?
Since I do not use c-41 except for in-house reproductions, I also use a non-professional system for developing c-41. This ar things I watch for. #1-Use distilled water with the developer, it is very sensitive to tap water issues if you have any. #2-I re-use the bleach and the fix pretty much equally. The good news is that you will be able to tell if the bleach is pooping out, in which case re-bleaching is Aokay. Just check the film before you put it into the fix. (you can use regular room light once you are through the pre-bleach). So I actually watch the process starting at this point as my choice for developing 4x5's is a translucent tupperware container. It is truly amazing, and since the bleach and fix can be more easily underdone than overdone; this helps guarantee by inspection that I let it work completely. #3-Also during the bleach step you need to shake the crud out of the container you are using. If it does not receive enough oxidation, it does not work properly or you have to nearly double the time. The other steps need gentle agitation as a rotary tube would offer.
One set of intructions I had for Flexicolor said you can renew the bleach by putting it into an oversize jug, say one gallon in a five gallon jug and shake the heck out of it. That provides plenty of oxygen exposure to recharge the stuff. I wonder how it would work to use a fishtank bubbler to recharge with. Plop it in and forget about it til next use?
Thanks for the tips. How would I know if the negatives were "under bleached / fixed"? I would guess that the exposed start of the roll would not be clear.
I checked out the .pdf file at the site given.
Seems like a *very* short chemical capacity. Kodak claims their C41 chemicals *must* be used on a one-shot basis in rotary tanks, as would be used on the CPE-2 processor, and they list a capacity of 12 rolls of 35mm film per liter.
They also list three (3) rolls of 120 as maximum (kind of puzzling - the others generally state one roll of 35mm as being equal to one of 120...?).
I would suggest visiting JOBO's web site, and checking out their Tetenal C41 chemicals. I've used these extensively, and have really high-quality, uniform results.
yes, i agree with you ed.