processing color negatives at home

Discussion in 'Film and Processing' started by mauricio_valenzuela, Apr 12, 2006.

  1. hello, i want to know if there?s a way to develop color negatives at
    home, using home products. like when you do it with the BW film using
    vitamin C etc..

    thank you

    Mauricio Valenzuela
  2. Yes: Developer for 3:15 @100.0F, wash, bleach for 6:30 @98-102F, wash, fixer for 7 to 10 minutes between 92 & 105F, wash, rinse in Photo-flo - laced water.
  3. Yes, you can develop color film at home, but it is not nearly as simple as Dan suggested. To do it well, you probably need a Jobo or some similar processor, specially designed to develop color film. No, you cannot use Vitamin C or that sort of thing. Indeed, you cannot get color images with regular black and white chemicals. You need special color chemicals--"C-41" process for color negative film. Also, IIRC, some of the chemicals, especially the stabilizer, are relatively toxic (unlike most B&W chemicals, which are relatively safe).
  4. Dave, you don't need a Jobo (I have two ATL-3 machines in my basement!) All you need is the right developer, strong bleach, clean fixer; then all that's left is nailing the times & temps... And even then, there's a lot of slop in C-41, since the common attitude is "I'll fix it in printing."

    Also, C-41 films coated in the last 5-6 years use different couplers, which do NOT require formaldehyde (formalin) stabilizers: Today, the final rinse solution is no more than glorified Photo-flo. Please see "Dye stability in C-41 & E-6" at:


    Developing E-6 at home is a whole different story, though!
  5. James G. Dainis

    James G. Dainis Moderator

    I think Mauricio is asking about using products found around the home as developers, much as some people fool with developing B&W in Vitamin C, horse urine, etc.
  6. In my previous post, I said that to process C-41 "well, you probably need a Jobo or some similar processor." (Italics added.) As Dan says, you need to "nail" the times and temperatures. For people who develop B&W by hand, development times under 5:00 are considered too short to be maintained consistently, and C-41 developer times are closer to 3:00; how many people can hold those times consistently? And B&W is essentially a room-temerature process, with developer temperatures of 68 to 75 deg. F / 20 to 24 deg. C. But C-41 requires maintaining temperatures much higher--more like 100 deg. F / 38 deg. C--which is harder to do, especially because the temperature tolerances are much less for C-41 than for B&W.
    If you just want to play around with it, go ahead and buy a set of color chemicals (C-41) and give it a try in a Paterson or similar hand tank. But if you want to get good results and process the film in a way that leaves it archivally stable, I think you are not likely to be able to do it with regular color negative film unless you use a processing machine.
  7. Dave, surprisingly, C-41 isn't quite as critical, even though the time required is 3:15 (195 seconds), as long as you don't undershoot the time .AND. temperature.

    In fact, my Jobo is programmed for 3:25, which gives a 1/3rd stop speed increase, to compensate for manufacturing tolerances down in the toe; while Ron Mowrey does (essentially) the same thing by overexposing by 1/3rd stop.

    The same thing holds for temperature, you need to maintain at least 100.0F (38.2C); but just as you can overshoot the time, you get the same effect by bumping up the temperature to 39.0C. In fact, for minilabs, since they use leader card transport (a variation of roller transport), manually raising the temperature is the only way to controllably push process C-41 film in these machines.

    [Well, I know one crazy Chinese guy who looked at his watch, and 10 seconds after the 35mm canister dropped into the waste bin, would switch off the processor for 30 seconds to get a one stop push... But I digress.]

    In any case, there's so much "slop" in the C-41 process that as long as you don't undershoot the color developer; and assure that the bleach and fix steps are carried through to completion, you'll be safe. C-41 has always been this way, since there's always been the optical printing step; and today even more so, since most all C-41 color neg film is scanned and output on a laser/LED photo printer (Fuji Frontier, Agfa D-Lab, etc...).


    You also raised the issue of stabilizer, which, for E-K & Fuji films the last 5-6 years, is a non-issue because the couplers & dyes are designed to (literally) self-preserve, in order to use Photo-flo instead of formaldehyde for the final wash.
  8. Dan;

    This stabilzer issue keeps coming up.

    Stabilzer is present in E6 in the bleach pre-bath. It contains formalin bisulfite, but more importantly the current C41 and E6 final rinse baths contain stabilzing agents and preservatives.

    Read the label and MSDS and you will see that it is not just a glorified photo flo! It protects film against deterioration.

    Ron Mowrey
  9. Ron, of course you're right about E-6 pre-bleach containing sodium formaldehyde bisulphite.

    On the other hand, I'm getting two different stories on C-41 film; and I'm puzzled:

    Last week Kodak film processing tech support tells me that C-41 films made in the last 3-5 years (but NOT Verichrome) have been reformulated so that the stabilizer used does not need formaldehyde; and that in fact the "Final Rinse" is essentially Photo-flo.

    Ron, whose counsel I trust, is telling me this same "Final Rinse" has mystical ingredients that preserve the dyes.

    What is going on?!
  10. Current C-41B stabilizer working tank MSDS.

    Product name: KODAK FLEXICOLOR Final Rinse and Replenisher, Working solution

    Product code: 1174259 - Working solution

    Weight %, name, CAS#

    95 - 100 Water (7732-18-5)

    < 1 Diethylene glycol (111-46-6)

    < 0.1 Mixture of C12-15 alcohol ethoxylates (68131-39-5)

    < 0.01 Magnesium nitrate (10377-60-3)

    < 0.01 Mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and
    2-methyl-4-isothiazolin-3-one (3:1) (55965-84-9)

    OK, what does what?
  11. James G. Dainis

    James G. Dainis Moderator

    Has anyone read Mauricio's original question? Using home products, things found around the house for developing color film? I suppose he already uses coffee to develop B&W but now he is wondering if Coffee, Vitamin C, horse urine etc, can be used to develop color negative film.
    Using coffee as a B&W developer.
  12. Has anyone read Mauricio's original question? Using home products, things found around the house for developing color film?
    My very first reply said, "No, you cannot use Vitamin C or that sort of thing." The whole point is that modern color negative film needs special chemicals to give color images, which I thought had been answered.
  13. Dan;

    AFAIK, the last two ingredients in that MSDS are stabilzing agents / preservatives for color films. I cannot comment any more that that.

    Therefore, use of just photo flo on color films is not sufficient for preservation of color images.

    Ron Mowrey
  14. Ahh, thank you!

    Are either of these last two (in the last line) miconazole, which is an anti-fungal?

    Mixture of three parts 5-chloro-2-methyl-4-isothiazolin-3-one to one part 2-methyl-4-isothiazolin-3-one

    Are the first three --
    (Diethylene glycol, C12-15 alcohol ethoxylates, and Magnesium nitrate) -- the ones you can't comment on?

    [It's a bit confusing, since the last entry in the MSDS is a 3:1 mixture of two ingredients]

    Thanks! Dan
  15. Well, I guess I'll have to wait to the 20th for B&H & Adorama to open up, to get some C-41 Final Wash. Looks like the Agfa variant that produces 100 liters for $8.50 is a Good Deal:
  16. Dan, two of the ingredients are photo flo. I suggest that you compare the MSDS of photo flo 200 and the above. The first two ingredients you mention are also listed in PF200, but I'm not sure about the magnesium sulfate. It might be a mild buffer.

    I also am not sure about the thione being the compound you mention.

    I can tell you this. Silver itself has antifungal, anti-mold properties being a heavy metal. So, B&W film has a built in anti-bug defense mechanism. Color film, which has the silver completely removed has no such defense mechanism.

    Therefore, contrary to a few who have rebutted my posts here and elsewhere, color films are more prone to fungal attacks. The formalin once helped prevent that, but with the elimination of formalin, it would be necessary to replace the antifungal properties of formalin with something else. I believe that this is one of the purposes of those compounds. It may be that they also offer some oxygen protection or UV protection. It may be that they also scavenge unremoved byproducts from the bleach and fix. IDK.

    In addition, color papers once used benzoic acid and sugars in the Type II stabilzer to prevent both oxidation of the dyes and attack by fungi as well as pH induced effects.

    Dyes are most stable at as is gelatin, between pH values of 4.3 - 6.7.

    So, there is stabilzer chemistry in a nutshell. Of course it is more complex than that, but there it is.

    Ron Mowrey

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