Home-processing C41?

Discussion in 'Film and Processing' started by terence_mahoney, Jan 13, 2006.

  1. Hello. I'm currently stockpiling C41 film in my deep-freeze because I
    have no intention of ever going digital. Of course it's all moot if
    it becomes impossible or too expensive to find a lab to process it, so
    I am planning to also stockpile processing chemicals. The one that
    strikes my interest is the Tetenal Press Kit, because it's powdered
    and should store indefinitely, and each kit seems (extrapolating from
    their 5-litre kit, which is however a liquid concentrate)like it
    should process about 10-12 rolls, which is just perfect for my use.

    I'd like to know if anyone uses/used the Tetenal Press Kit for C41
    (colour or chromogenic, I use both)and if it works decently. I
    apologise if this has been discussed before. (PS, please let's not
    have anyone brush me off as a lunatic for my actions with the "film
    will always be around" line, I've got my eyes open and each day points
    more and more to the naive optimism of that notion).
  2. I have not used the Tetenal Press Kit, but I have used another powder C-41 kit (Arista) sold by Freestyle. The powders are easy to mix and use but have a limited lifespan once mixed. I've since switched to a liquid concentrate kit so I prepare only what I need for the day's processing.

    Correct me if I'm wrong, but I believe the Tetenal Press Kit lacks the stabilizer step, which is necessary to prevent the dyes from fading.
  3. Sorry, the Press Kit DOES include stabilizer in powder form.
  4. I process my own C41 & E6 film (just processed 11 rolls of C41 120 & 220 yesterday!), and it is quite easy: You can buy the "real" Kodak or Fuji Hunt chemistry that the pro's use, for a fraction of the cost of these half-assed "kits" -- And you'll get better, more consistent results. What I do is shoot a lot of film, and store the exposed rolls in the freezer for a few days or weeks until I either get enough for a big batch, or until I shoot something I want to see right away.

    Since I use a Jobo ATL-3 processor, managing the chemistry is easy:

    Working backwards thru the C41 process, I use Fuji Hunt stabilizer (which is cheap) and use 1% formaldehyde (99% water) instead of 100% water to "spike" it.

    Next, I use a common 2-step fixer for B&W, C41 and E6: This is acceptable if you put a wash step after the bleach in the E6 and C41 processes.

    Bleach is the most expensive component, and here careful management will reduce your cost to pennies per roll: Just mix it up in a 5 gallon bucket with lid (to keep out dust) and use a $6 aquarium pump and 49 cent bubble stone to keep it aerated; then replenish as needed.

    For the C41 developer, I usually mix 3 liters of replenisher, then from it make 1.5 liters of working tank solution. I then run the first batch, catching the effluent into a 4 liter wine bottle and mixing in a generous amount of replenisher, i.e. some C41 films use 50% more developer replenisher than others, so I use the higher figure for all film and "round up" the amount as a cushion. I continue this process until I finish my batches.

    At the end of the batch, I replenish (if I have enough) and cap off the bottle, saving the seasoned working tank solution in the closet, since it will keep for about a month. If I don't have enough replenisher to completely replenish, I still pour it in and save the seasoned liquid, marking on the label the shortfall. In this case, the next time I run, I make a fresh batch of replenisher; then add in enough to generously cover the shortfall, i.e. if I needed to add 800 ml before, I dump in 1 liter or replenisher, yada yada yada...


    Al this being said, I think you're killing and burying film too fast! This is especially so for C41 film, with tens of thousands of minilabs in pharmacies, grocery stores, and department/big box stores (Wal-Mart, Target, etc...)

    What you don't realize is that the disposible camera market is literally exploding in volume, especially in China. If you don't believe me, Lucky & Kodak have entered into joint ventures to make color print film in China for the burgeoning India & China markets, where digicams are still out of price range for their working stiffs.

    Yes, film volume is dropping, with Ilford & Agfa going through bankruptcy. That being said, acres of color negative film is still exposed & processed every day for the motion picture industry for print distribution to cinemas, as the resolution and contrast ratio quality of digital projection is only that of about HDTV; and theater owners -- Now more than ever -- need a compelling reason to attract moviegoers who could otherwise stay at home and watch it via DVD on their LCD or plasma TV... See IMAX! :)

    Cheers! Dan
  5. I use the Tetenal Press Kit, with decent to good results. Its been a few months since I did a run, but I believe the kits process ~12-16 36exp rolls, depending on the ISO. I scan all of my film, and haven't tried to do any traditional printing off of the negs. That said, I get good scans. The star trail photo in my portfolio is NPS processed in the Press Kit chemicals.

    Dan is correct that you can get cheaper, and probably better, results using the Kodak or Fuji chemicals. However, that's only true if you're processing a good amount of film. I don't shoot C-41 very often, and probably only have a dozen or so rolls every 6 months. I save them up, and run them all at once. The mixed chemicals only last a couple of weeks, at the most. I'm not sure how long the concentrate versions last, but I think I'd have a lot of waste if I was using the Kodak chemicals.

    My total cost per roll is similar to or slightly more than what I'd pay for just processing at the local Target. However, by processing things myself, I remove a lot of the risk from careless high-school age operators.
  6. Thanks for the answers so far fellas. I'm not burying film yet, and have no plans to process it myself until I have no other reasonable choice. But with probably 20 years of shooting years left I know eventually I'm going to be at that point and I don't want to have to get digital because I was blase about it now. I don't care if doing it with bulk liquid chemicals is cheaper, it won't be for me because the stuff will go bad, I'll never have enough film at one time even if I freeze the exposed rolls for a month. That's why I'm interested in the powdered one-shot small-batch kits.

    I read though that the Blix can deteriorate even in the powdered form, something about the ammonia thiosulfate. Anyone know if that's true?
  7. As far as how long liquid concentrates last, I've been using an Arista kit now for more than six months with decent results. I take pains to displace oxygen from the bottles before sealing them up. The developer is the first to go bad-- it turns dark when it oxidizes, and it hasn't turned dark yet. I aerate the blix with an aquarium pump and airstone before use.
  8. Maybe I wasn't making myself clear. I need the unopened chems to last 10-15 maybe 20 years. And since I don't know how often I'll be shooting, it should be just enough in each kit to do maybe 10 rolls.
  9. Chad, the Chilean star trails photo has wonderful composition... And you must have lugged a pretty heavy tripod to get it that sharp, too!

    Now the Bad News: Graininess. I'd like to see the actual NPS 160 neg, as I'll wager it's quite "thin," causing this grain in your scan. Alternately, the color dev soup could have been weak or not quite up to 100.0F, yielding unintentional pull processing.


    Terence, you wrote "I read though that the Blix can deteriorate even in the powdered form, something about the ammonia thiosulfate. Anyone know if that's true?"

    Therein lies another problem with these "kits:" That they try to shortcut the C41 process (as well as the 3-step E6 hack) by using a mix of bleach & fix ("blix"), which deteriorates rapidly because the bleach required is much stronger than the blix solution in RA4 (color print paper). You'll "get away" with it if you mix it and use it Right Away; but the archival value is questionable.

    If you're a "reporter" (and haven't switched to digital for "speed to market") and need to get the shot of that politician to the photo editor, then one of these kits are OK.

    On the other hand, if you snag a shot like Chad's, then you'll want to keep the negative preserved for a lifetime if you take it to the next logical step: What good is a negative (or chrome) if all you plan to do is scan it, as opposed to printing it in an enlarger??

    ...And, if this is the case, why screw around with anything but the best chemistry and the best process for your precious film?

    Cheers! Dan
  10. Terence wrote "Maybe I wasn't making myself clear. I need the unopened chems to last 10-15 maybe 20 years. And since I don't know how often I'll be shooting, it should be just enough in each kit to do maybe 10 rolls."

    I think you're way overestimating the actual demise of the C41 process! Let's look at each step in the process:

    Stabilizer: You can always get your hands on formaldehyde from your local mortuary or hospital lab... Last time I looked, people are still dying to get in!

    Fixer: Still will be used for x-ray film until the cows come home. Since the C41 fixing step -- Like every other process -- is a terminal process, you can use any fixer provided you make sure it's not loaded with silver (exhausted) from previous use.

    Bleach: And how do you plan on processing those RA4 enlarger prints without bleach?! As long as you can print, you'll have bleach solution.

    Developer: Now this one is a bit tricky, as it involves CD3. However, I know chemical companies in India and China make CD3, so if there's a buck to be made, they'll brew it.

    Keep in mind that there are home-brew formulas for E6 floating around on the Internet; and I'm sure formulas will pop up for C41 color dev as well as the rest of the process.

    Also, and let me repeat, color negative film (and the similar ECN-2 process) will still be used for motion picture film for distribution of prints to cinemas!

    Please take a look at http://www.kodak.com/US/plugins/acrobat/en/motion/support/processing/h247/h2407.pdf where you'll find the ECN-2 formulas, which can be adapted (to a degree) for C41.
  11. I store my E6 working solutions (in plastic bottles) in my deep-freeze at -22 Celsius. Froze a bunch over 6 months ago and just processed some film last weekend with great results; no noticeable changes with a test roll. I can't imagine a whole lot of oxidation occurring at that temp.

    I mainly freeze my chems for convenience; it's a lot easier (and more accurate) to mix the entire 5L kit at once and freeze into 1L sized bottles than it is to try and draw off small amounts of chems from the concentrates every time I want to process. When I processed last weekend, I simply took the 6 frozen bottles from the deep-freeze, placed them in the sink with hot water, they thawed out in 45 minutes and I was ready to process. No need to haul out my graduates, and other related mixing crap and no need to try and evacuate air or find smaller bottles for the concentrates; easy as pie.
  12. Three necessary additions;

    Not all kits are born equal. There was a review of kits in the old Darkroom Techniques magazine that showed the variations in results from 5 or 6 different kits. The developer is the main culprit. The developer may introduce major or very minor variations in the results, but they don't equal 'real' C41 from Kodak and the Fuji product is pretty close.

    Do not use any acidic fix on C41 or E6 films. The pH of the fix must be between 6.3 and 6.7 and must not have a hardener in it.

    Don't use a Blix with color films, or you risk color degradation due to retained silver. Make sure the fix is an ammonium hypo fix or you may have retained silver.

    Ron Mowrey
  13. Ron,

    You wrote "Do not use any acidic fix on C41 or E6 films. The pH of the fix must be between 6.3 and 6.7 and must not have a hardener in it."

    But, I'm puzzled: Isn't any liquid below 7.0 pH acidic?!
  14. Now the Bad News: Graininess. I'd like to see the actual NPS 160 neg, as I'll wager it's quite "thin," causing this grain in your scan.
    Dan, your right, the star trail neg is thin. But I think that is more a result of the subject nature - there obviously wasn't much light, and so I underexposed things a fair bit. I do have other examples from the same batch of film and processing that were exposed properly and show less grain.
    I'd love to use the Kodak chemicals, but I don't because of the quantity of developer that I'd waste, and also because I don't have a real darkroom. All of my processing is done in my kitchen sink. Everything (tanks, chemicals, processor) has to be packed up and moved into storage each time I'm finished with it (or want to cook dinner). That's also why I'm not doing any traditional printing, but instead choose to scan and print digitally. If I had a darkroom I might be using Kodak chemicals and also printing.
    I used to process E6 in a similar manner, but decided it is more cost effective to send to Fuji (~$5/roll). If I could find something similar for C-41, but only just processing, no prints, and could be sure that the negs would not be scratched, then I'd do that. I've tried asking for 'no prints' at the local mini-processors, and more often than not the film ends up getting rolled up and jammed back into the cartridge. I also tried a local 'pro', and ended up with green, grainy negs, for the rock bottom price of ~$8/roll.
    That said, I do think Terence is slightly overconcerned here. You'll still be able to process C-41 at the mini-lab for years to come. Afterall, someone has to handle all of those one-time use cameras that get sold to forgetful tourists!
  15. And you must have lugged a pretty heavy tripod to get it that sharp, too!
    Dan - That was taken with my FM3A on my trusty Bogen 3001. I was fortunate to be able to tuck the tripod right behind the shelter of another dome (the one I was working in), so it was protected from the wind.
  16. Which would make sense, relative to cheap metal and not-cheap carbon fiber anything of decent quality and steel could be considered heavy.
  17. Dan;

    Yes, that pH range is nominally acidic.

    I'm referring to the standard acid fixes with pH values below 6.0.

    Do not use them.

    Ron Mowrey
  18. ", and more often than not the film ends up getting rolled up and jammed back into the cartridge." heads must roll
  19. trw


    Quoth Dan Schwarz: "Yes, film volume is dropping, with Ilford & Agfa going through bankruptcy."

    Ilford is not in recievership. http://ilford.com/html/us_english/pr/prht.html
  20. Thank you Chad Bender, the one person who responded that actually has used the Tetenal kit and addressed my original question. I guess I will have to contact a chemist to ask if the Blix powder will degrade over time or if these kits can be stored for many years and work properly when activated.
  21. I have one of the Tetenal Press kits that I know is at least three years old. I also have some unimportant film that I exposed some time ago. Based on this thread, I'm kind of curious now. So if I go ahead and try the kit, how do I tell if something's bad about it (short of not getting any negatives)? It's pretty hard to tell if something is off about a color neg just by looking at it. I don't do color darkroom any more, and even if I did I would filter to compensate for any color shifts. Same thing for scanning it. If there's a longevity issue it still may not show up for months or years. So, how to tell if the kit is not working right?
  22. Hey! Great! The statement I found (in photonet archives)is:

    "Ryuji Suzuki , may 06, 2002; 11:03 a.m.
    Tetenal C-41 Press kit gets mentioned for its powder preparation and "long shelf life." Warning: the blix has shelf life of maybe a year or so, because it contains ammonium thiosulfate in dry form, which likes to decompose. If you see solid sulfer precipitation when you dissolve into water, your powder is pretty old. Mine turned out that way."

    Maybe that helps. If this cat is on the level you should know just by looking at the solution once you mix it up. Then again maybe he mixed it with well water or something. Hard to sort the scat from the truth on the internet.
  23. Terence Mahoney wrote:
    Thank you Chad Bender, the one person who responded that actually has used the Tetenal kit and addressed my original question. I guess I will have to contact a chemist to ask if the Blix powder will degrade over time or if these kits can be stored for many years and work properly when activated.
    Newsflash: Ron Mowrey is indeed a retired engineer from Eastman Kodak, and is the holder of several patents, including Patent Number 3,706,561 on rapid fixer.

    Dan Schwartz
    Cherry Hill, NJ
    Click here to visit my home page!

    [Note: All links open a new browser window]
  24. So I went ahead and mixed up the kit I had and gave it a shot. The results were okay.

    First some observations on mixing the chemicals. I mixed the blix first to see if I would get sulfur precipitates like mentioned in the quote. I didn't see any at first, so I went ahead and mixed the developer and stabilizer, but after an hour or so I did see a small amount of granulation just in the very bottom of the bottle (I used 1 liter soda bottles). The developer seems to have mixed up fine, but the stabilizer not so good. The flakes didn't seem to want to dissolve, even at the highest mixing temperature. Eventually they disappeared, but I think they just broke up rather than dissolving, because if I tipped the bottle to move the air bubble around inside, I could see that the inside had grains sticking to the wall.

    As for developing, I used a two minute pre-wet, then developed for the normal 3:15. I assumed the blix was weak, so increased the time for that step by 50%, then washed it and put in the stabilizer for double the specified time. Is the stabilizer supposed to act like a surfactant (like Photo-Flo)? I pulled the reel out and looked at it and the left-over liquid was bunching up and not sheeting off at all. So I put it back in the tank and gave it a last rinse in water with a drop of LFN, then hung it up to dry. Would that last rinse have un-stabilized it?

    Anyway, there are negs on the film. The troubleshooting chart in the instructions has two symptoms of insufficient bleach/fix: "cloudy streaks and areas after drying" and "mask appears brownish". These negs don't have cloudy areas or streaks, but the mask may be browner than normal (the film is 120 Superia 100, but I don't have any professionally developed negs to compare to). The mask looks a bit more coppery than most other films I've seen.

    I tried scanning some of the negs; you can see them here:




    They didn't seem to require any heroic color changes to get them to this state, but then the colors seem kind of muted too (though part of that might be the age of the film, expired Nov 2000 but kept in the freezer).

  25. It sounds like I should just stockpile B/W film and chemicals and content myself to shoot just that once commercial C41 processing goes the way of the dodo.

  26. Terence,

    Shooting film is one thing; making prints is quite another... Unless, of course you plan on shooting color transparency film and projecting it!
    By the way, Ron Mowrey also has a patent on blix, so he knoweth what he speaketh about when he admonishes you for using it as the tail end of C41 or E6 film.
    Again, the issue for C41 chemistry future availability will be the developer, not the bleach and fix, which can easily be formulated from scratch, as can many B&W developers.
    And, this is the worst case scenario, i.e. Kodak and Fuji both completely shut down.
    My advice, if you're REALLY serious about chemical availability 20-30 years down the road, is to start TODAY with the C41B process with REAL Kodak &/or Fuji Hunt chemistry, and learn the process. Then, using test rolls of cheap film, start by making your own fixer using Ron's recipe:
    4. I gave the formula for a super fix to Bud Wilson at the formulary expecting nothing in return. It is ammonium based and near neutral in pH. I include it here for reference. It is not free to use for profit by anyone but Bud if he desires. I wish to get nothing for this formula. I disclaim any liability that might arise from its use.
    • Ammonium Hypo solution 150 - 200 ml/l
    • Ammonium Sulfite 10 g/l
    • Ammonium Thiocyanate 10 - 100 g/l
    • pH 6.5 - 6.7 at 20 deg C with 28% acetic acid.
    If you wish extra power add:
    • Thiourea 10 - 100 g/l
    • KI 1 g/l
    In any event, do not use KI with papers, as it slows fixing rate, but accelerates fixing rate of films. Use with caution with color films, as it can cause or accentuate any cyan leuco dye problems. Don't go overboard and use the max of all of those ingredients. That is a possible range for any one of them at a time. If you max out all of them, you can actually slow down fixing rather than increase it. I used to test variations with strips of film snipped off a roll for this purpose.
    It is a very rapid fix for films and papers (minus the KI for papers of course) and can be made even faster by the group of proprietary materials patented by EK which I will not get into here of course. These are of particular use in color fixes.
    Make sure you wash film/paper, equipment and hands well, and take precautions for toxic materials used. This fix like most all fixes is a powerful fogging agent for film if small amounts get into a developer. Thiourea and all thiocyanates increase the hazard of photographic solutions.
    This formula is loosely based on USP 3,706,561 granted to Rowland Mowrey, Keith Stephen, and Eugene Wolfarth.​
    Dan Schwartz
    Cherry Hill, NJ
    Click here to visit my home page!

    [Note: All links open a new browser window]
  27. Yep, sounds like I'll be sticking with B/W. I'm no mad scientist, I just want to tear open and envelope, mix it up in water and go to it.
  28. I don't know if anyone is still following this thread, but I thought I would add on what I've got.

    In addition to the two rolls (of 120) I ran through the three year old kit I mentioned earlier, I had another four rolls of unimportant film, so I decided to give those a shot as well. When I got the bottles of chemicals out, I found that the stabilizer had finally dissolved into solution since my previous attempt. There was no additional sulfur precipitate visible in the blix. I ran two rolls through, again with the 9 minutes in the blix. This time I didn't do a wetting agent rinse after the stabilizer; the water didn't run off evenly so I got some water marks and in a couple of places the film actually crinkled because it didn't dry at the same speed where the water drops were compared to the areas around them. Finally I ran my last two rolls through. I tried extending the blix time to 12 minutes to see if it would have any effect; I don't see any, the film base still looks a little more coppery than normal. Also, I did use an LFN rinse on this batch and they dried normally.

    I just got another Press Kit in the mail today, and I see they've made some changes compared to the old kit I had. The old kit had a single packet of blix concentrate, the new kit has the blix split up into parts A and B. I would guess that they did this precisely to reduce the degradation over time, so maybe the kit has a better shelf-life now? Also, the instructions have been condensed. Some of the tips that are in the old instructions are missing, but on the other hand they have added information on push-processing and chromogenic B&W. Finally, the capacity they state now is 8 rolls of 120 (or equivalent). They have added a vague paragraph about how, if you're willing to take the risk, it is possible to process 50% or more than is stated, but they no longer provide the chart of corresponding time increases that was in the old instructions. I think I will hang onto the old set of instructions for additional reference.
  29. Fixer: Still will be used for x-ray film until the cows come home. ----My wife's a doctor at Johns Hopkins. They've already gone digital for x-rays there, though they still use both. My dentist is all-digital for x-ray.
  30. Craig,

    I don't think they'll stop making x-ray film for a long, long time. And, even if they do, ammonium and sodium thiosulfate -- The active ingredient in fixer -- has other uses in industry besides in the photographic industry; and that is my point.

    The only chemicals used in C41, E6 and RA4 that don't have other uses are the color dyes used in the color developers.
  31. Jerry,

    Color film developing is totally unlike B&W film: It's a very precise chemical process, with tightly maintained time, temperature, specific gravity and (especially) pH values. You are basically developing three separate pieces of film, and you have to match the D(min) & D(max) points as well as the 3 separate contrast curves.

    Even if you play with the so-called first "B&W step" in the E6 process, you can still get color shifts if you don't nail it.

    When you use half-assed chemicals and processes, such as "blix" and 3-step E6, you're looking for trouble.

    Also, you should *really* pay attention to Ron Mowrey's admonishment on using the strong blix required for E6 & C41 -- He has patents on the weaker blix (which does work) for the RA4 process.

    Cheers! Dan

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