3 Step C41 processing with Jobo

Discussion in 'Film and Processing' started by danny_liao, Nov 9, 2005.

  1. I've been processing my own color negs (Portra NC & VC) with my Jobo using the Arista's 3 step processing kit. I've been getting heavy greenish cyan cast (negs looks really magenta) on my images after I scan it with no color management. At first I thought it was my scanner so I scanned some negs processed from a lab and they came out fine. I was told that I needed to increase the time in the bleach but that didn't help. I also increased the time in the developer with no avail. It's not a temp problem cause it stays the same throughout the process. Anyway, I need some suggestions. Attach is a image with the color cast. [​IMG]
     
  2. Your picture looks fine to me. The green cast is something that you filter out when enlarging (Darkroom) or scanning (Digital) All c41 colour negs have a contrast control mask built in to the emulsion. Different C41 chemicals give slight changes to the density and colour of this mask; it matters not. If your negs have proper underlying colour and gradation then you have exposed and developed well. Sort out your scanning!
     
  3. Richard,

    Will going to a 6 step process help eliminate the cast?
     
  4. You might get better results with Kodak chemicals. I've heard quite a few people complain about inconsistency and odd results when using non-Kodak or non-FujiHunt chems.
     
  5. This is a well-known phenomenon, although it is never mentioned in the manuals of the developing kits: the use of a bleach-fix directly after the developer (instead a separate bleach and fix, like in the standard process) leads to higher density of the colour masks in negative films. IIRC, this is caused by the oxidation of developer by the Blix. It should not harm your pictures and can be easily corrected by filtering (either conventional or digital).

    Unfortunately, the most important selling point for home-processing chemicals seems to be "easy" and "comfortable", so there is a lot of stuff around which gives non-standard results, although it claims to be "real" C-41 or RA4.

    BTW, using bleach and fix separately will cost you around 4 minutes per processing, but will save you some money, as bleach and fix have a higher capacity and can also be stored for a longer time.

    Aditionally, fix alone can be easily de-silvered and discarded (this is nor possible with Blix).

    Regards

    Georg
     
  6. Danny;

    I have to disagree with George in part. Sorry George.

    A blix in C41 or E6 rather than a bleach then fix sequence will most likely cause silver retention which will darken the film in high density areas, and may cause color crossover.

    If the blix is properly formulated, it should not form a darker 'mask' in the film. In fact, the mask is preformed in the minimum density area during the coating process. The mask is altered in the higher density areas of the negative during development and can only be interfered with by the blix if silver is retained.

    Blixes for film are subject to rapid oxidation and decomposition, and can therefore lose activity rather rapidly. They also are subject to formation of orange iron stains in the film, and with poor keeping they can oxidize color developer and form a stain. Use of fresh blix with a short rinse or stop after the color developer will help eliminate this problem.

    Kodak has published instructions on this as it can even be a problem with the bleach then fix process cycle under some conditions.

    Ron Mowrey
     
  7. Danny, I have used Arista paper chemicals in the past on Kodak paper. All prints faded severely as of today while those printed with Kodak chemicals remain vivid and beautiful. Fortunately I still have the film that I can scan and print again. Arista chemicals are for fun but if you are serious about quality results you should use Kodak or Fuji C-41 chemicals as Kodak and Fuji share pretty much the standard of C-41 process. Fuji chemicals are not available in most photo supplies so that leaves you only Kodak to consider. I use Kodak C-41 chemicals all the time. It's 4 steps (develop, bleach, fix and stablization). For about $50 you get a gallon for everything to process 20 to 30 rolls 35mm/36 exposures. If you buy another gallon of developer at $12 you get to do another 20 to 30 rolls again by reusing the rest of the chemicals one more time. That's $65 for 40 to 60 rolls. That's a terrific deal. The only problem is you need to have that many rolls to process. Fortunately except the developer (only after mixed) all other chemicals will last a long time. Even if you waste half of the developer you are still in good shape considering all the fun you get in processing all your own films.
     
  8. Danny, since you have a Jobo, and since a few extra minutes of time isn't an issue, just go with conventional Kodak Flexicolor chemistry in 5 gallon components, and you'll nail your C41 process to the wall. A five gallon kit for the developer is $26.50 at B&H, one gallon of bleach is $26.50 (5 gallons is $88.50); while fixer & replenisher is $7.95 for 5 gallons; $32.95 for 25 gallons.

    Bleach-fix mixture may be OK for RA4: Ron is the expert; and although he says you can use "blix" in C41 & E6, my basic question is,

    With the "real stuff" so damn cheap, why screw around with these half-assed generic kits to begin with?! :)
     
  9. By the way, you don't have to have a storefront to buy chemistry from minilab/photo lab wholesalers: You'll want to find one local to you (or in the nearest city) and get them to deliver, saving you from haz-mat shipping surcharges.

    Filmart is decent, and has pick-up: http://www.filmart.com/cgi-bin/filmart/category/cat79/Chemistry.html

    See: http://www.filmart.com/cgi-bin/filmart/item_list/cat199/Flexicolor_Chemistry.html

    http://www.google.com/search?hl=en&lr=&q=photo+minilab+supplies+
     
  10. Danny,

    I'm puzzled: You're shooting expensive Kodak pro films; and then wasting any advantages with a "blix;" which, as Ron has previously pointed out, are "sensitive" to oxidation, especially with the stronger bleach need for C41 film. For me, that's too much to gamble on, when REAL chemistry, in five gallon components, is so damn cheap.
     
  11. Thanks for all the help. I'm certainly going to try Kodak chemicals from now on. The reason why I went with Arista is because I'm still in the testing/experimental stages with developing C41. You know how that goes.

    I have another question for you guys. I have a ATL2 unit which contains six bottles. I use the first 3 for B&W and the last 3 for C41. If I go with a six step process, is it okay to use the same bottles that I use for B&W? I never leave me chemicals in the bottles and always rinse out the system after each run, but I'm still wondering if it's safe from contamination?

    Thanks
     
  12. "Thanks for all the help. I'm certainly going to try Kodak chemicals from now on. The reason why I went with Arista is because I'm still in the testing/experimental stages with developing C41. You know how that goes."

    If you use the real stuff, then you don't need to ``experiment"
    "I have another question for you guys. I have a ATL2 unit which contains six bottles. I use the first 3 for B&W and the last 3 for C41."

    No need: Set up the six bottles as follows:
    • B&W Dev 1 (like D76)
    • B&W Dev 2 (like Pyrocat-HD)
    • C41 Dev
    • Acetic acid stop bath
    • C41 bleach
    • C41 liquid rapid fixer -- Also use for B&W only if you insert a rinse between bleach & Fix
    The advantage of this is that you can insert a stop bath after the C41 dev before rinsing, which can give you tighter control, especially when pushing & pulling...

    Cheers!
    Dan Schwartz
    Cherry Hill, NJ
    Click here to visit my home page!
    Webmaster: The Fox News Critic and Lisa Fiel Photography.

    [Note: All links open a new browser window]
     

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