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  1. #1

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    C41~ start from 0~

    Greetings to all photography lovers~

    I am doing classic photography for quite some time now. So far, I worked in the lab with B&W and got some very decent results. However, I would like to start with color negatives and C41~ Now, I saw there are dozens of topics concerning this matter, and just as many answers, and I'm sorry If I have to post another one...

    What I want to know at this point is:

    - What are the needed chemicals? ~Mind You I am searching for the most basic stuff (like D76 or ID11).

    - Can C41 be done in a room temperature without baths and heaters? ~I know a very precise temperature is needed, but is improvisation possible? For instance, I used to develop B&W just this way, with a chart of developing times for each room temperature from 18-25 Celsius. I found it easier than to heat up or cool down the developer, and the results were quite decent.


    Thanks~

  2. #2
    mts
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    Needed chemicals are available in kits, or in alternative scratch-mix processing documented in other threads here. There is essentially no departure possible for C-41 processing. Kits and alternative scratch-mix produce results close to the official formulae, most quality kits being somewhat closer to official Flexicolor. C-41 consists of developer, stop, bleach, fixer, and stabilizer with washes in between, although some processing variations are given for the various kits. For example, some kits use blix (combined bleach and fixer). These are considered by most as inferior to using separate bleach and fix. Bleach and Fix chemistry is tuned for both pH and composition to be compatible with C-41 dyes. B&W developers cannot be used because they contain no color couplers. Only one developing agent known by tradename CD-4 is used for C-41 processing.

    C-41 results at other than the 100F design temperature are definitely inferior, although only the developer is critical and needs to be within one degree for correct color balance. That said, color balance can be corrected slightly in printing or scanning so in practice you can deviate a couple of degrees from 100F. The other solutions bleach, fix, and stabilizer process to completion and are less critical with regard to temperature, but need to be within a few degrees of 100F to avoid problems that would occur by thermal shock to the film. Likewise for the final wash that is followed by stabilizer--you cannot process C-41 without a source of hot water, but I find that temperature can be controlled adequately by using a water bath and the hot/cold faucet adjustment to regulate the washing temperature. Processing for modern C-41 has a different formulation for the stabilizer since the emulsion contains some of the necessary chemistry. Older films require stabilizer that contains formaldehyde, but the older chemistry can be used with modern films.

    C-41 is simpler than B&W processing because there is no variation possible by chemistry adjustment, i.e. there is only one developing agent possible. Different bleach formulations are possible, but some of these will affect the color dyes or will not work at all. Processing technique must be consistent and controlled however; moreso than for B&W to maintain the correct temperature, but I find sink processing works well for 35mm at any rate. If you happen to live in the tropics and have 100F darkroom temperature, then you will find it quite easy to process color negative, but you may find it necessary to work in your underwear.
    By denying the facts, any paradox can be sustained--Galileo

  3. #3
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    There are presently 2, count em two active threads with up to date info.
    Up to date being the key because products get dropped faster than a pair of levi's at the Chicken Ranch.

    There is also this sticky thread

    http://www.apug.org/forums/forum40/9...-get-them.html

    The important thing to note is where you are located because product availability varies widely worldwide.

    And imo I wouldn't bother pursuing room temperature process but that is just my opinion.
    It isn't that difficult to get solution temps up the the correct temp and the developer is the one that needs to be spot on with bleach and fix allowing a bit of fudge factor (within reason).

  4. #4
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    There's a C41 section in my FAQ; link in signature; has links to a few more APUG threads and info on what to buy.

    No, it doesn't work at room temperature. It needs to be at the right temperature in order for the separate colour channels to not crossover.

  5. #5

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    I would add, if it has not already been said, that you should add a step between the developer and wash using a stop bath for 1 - 1.5 minutes. In my experience, the stop bath ensures absolutely predictable results and uniform development. Since using a stop bath immediately after the 3:15 developer, I have had great results with C41.

  6. #6

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    Thanks for the responses~

    I saw the links which gave me a good insight on what and how to do. I live in China and that means using a local alternative, since shipping from the US would cost like hell. Also, as this is my first time, I wouldn't need more than a supply for 50-10 rolls of film.

  7. #7
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    Hi O'Brien, I too live in China. You can easily purchase Tetenal C-41 kits off of www.taobao.com. I see most suppliers posting from Shanghai, but they ship quickly and reliably. I live in Beijing and have no problem receiving kits when needed.

    Tetenal is a 3 bath kit, meaning it uses blix. Blix goes bad more quickly than separate bleach and fix, and there are threads here that cover other issues regarding the mixed bath. But Tetenal is just about the only game in town in China, so it is what it is. I suggest saving up your films until you can do a good batch at once, using up the working solution so you have no worry regarding it aging on the shelf between uses.

    Regarding room temperature processing. Search this forum, there is another thread, started by me recently, where this was explored (again) in gory detail. Specifically Athril and PE discussed at length the use of a divided developer to replace the first developer step. The divided developer works to completion, making the result less susceptible (but not immune) to color crossover. Athril got quite good results from this, though he and PE agreed it wasn't perfect. However, for everyday images, or those you don't plan to enlarge but instead post process by digital means, you can probably easily deal with the mild color crossover.

    The downside of that solution is you'd have to mix your own chemicals from scratch, and acquiring those raw materials in China can be difficult unless you speak the language well. I've never tried it, but when I move back to the US, in fact I will give it a try.

    A Tetenal kit (to make 5 liters of working solution) on taobao.com will cost about USD$100-$120. (600-700 RMB). If used efficiently, one kit will process about 60-80 rolls of 35mm film (36 exp). It is more expensive than in the US, but not prohibitively so. Note that you don't have to make the full 5 liters all at once. You can make just enough working solution for your needs, reusing it until you either hit the limit for that volume, or it goes bad from sitting on the shelf, or you start getting bad negatives...

    If you live in Shanghai you can go to the big camera mall there and buy it directly. If in Beijing, you can go to the Wukesong market and try to find some, but usually the chemistry retailers there are all out. Taobao is the most reliable and convenient source.

    Good luck! And if you are in Beijing, you should join the photo group on Facebook, "Beijing Photo Walks". A few of us in that group do film, and can help you further.
    Last edited by chuck94022; 05-13-2013 at 04:03 AM. Click to view previous post history.

  8. #8
    chuck94022's Avatar
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    O'Brien, one more thing: check my thread on "MacGyvering" a tempered water bath, also in this forum. You can easily build a very accurate tempered water bath out of stuff you can purchase from taobao.com. Definitely takes the pain out of highly accurate color processing, and the unit only takes a few hours to construct.

  9. #9

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    I live in Hangzhou, some 200 km south of Shanghai~

  10. #10
    chuck94022's Avatar
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    Beautiful place, great place for a camera! Taobao should work for you, or just ride the train to Shanghai and pick up some chems!



 

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