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  1. #1

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    Question about Unicolor k2 chemistry

    Hi, as this is my first post, i'd like to introduce myself a bit.
    My name is Paul and I go to a tech school in NJ, US. In the beginning of last year I realized that my school has a photography club along with their very own fully stocked darkroom built in the mid 90's. I joined, and realized that there were only 2-3 real members, and the place was rarely used. Anyways, my interest in film photography grew more and more, and I love spending time in the darkroom. Currently, we only do black and white photography, and I've always been discouraged from trying color by the other members.
    As of now I spend way more time in the dark room than the other kid (there really is only one more active kid in the club) and I've tried to read everything I can on the subject. I've also been snooping around the room more and more, always finding some old machines that no one's touched for a good 5 years. Well one of these old machines happened to be a Fujifilm CP-32, and after figuring out exactly what the hell it did, I cleaned it out and but some black and white chemistry in it, ran some prints, and it worked great.
    Today I found some color chemistry, which brings me to the point of my post.

    I found an unopened box of Unicolor K2 and RapidScan 41 developer, along with a complete Unicolor Uniprint RA4 kit. Now the k2 box only has developer, and I was wondering whether or not I can use the blix from the RA4 kit for film developing. I am also lacking stabilizer, and I can only find kodak stabilizer, would this work alongside the Uniprint?

    Thanks for any help, and that I've received from reading this forum

  2. #2

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    You don't need stabilizer for modern color prints. You DO need stabilizer for color negative film, if you want your negatives to resist fading. Kodak C-41 stabilizer is ideal. The blix in RA-4 is not suitable for film...way too weak. You need a separate bleach and fix ideally for color film. You could beg some bleach and fix from a local mini-lab, if you do not want to order some. Kodak C-41 color negative film chemistry is sold in individual components.

  3. #3
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    CP-32 use notes.

    The cp-32 is likely a Fujimoto, not Fuji Film. I fly a CP-31. For RA-4 you usually run the chemistry at 95F, and the roller speed at 250mm/min , which gives 45 seconds per bath. You can run the first bath as developer, second as blix, and third as a rinse if you don't have the associated wash dry module. Or you can run second bath stop, but the rollers really mean there is little carry over between dev and blix. Below are notes I have gathered over the years on RA-4, which is what colour print paper uses as a process. In the beginning I would have an outside lab do your negs. Starting from kits are a good idea after that for those moving to home brew. The nice thing about a CP processor is that they only need 2L of chemistry. Be sure to rinse well after you drian the thing, to keep the rollers from dropping cruddies on your prints when you start it up the next time.

    RA-4: Colour Prints from Colour Negatives Process by Bill Laut., Dec 1998
    The developer is based upon one that Bill Cox gave me, and the Blix was reverse-engineered from a Besseler RA4-AT kit and then diluted down for economical one-shot processing (which I'm currently also doing to the developer). I would also like to express my appreciation to Ron Spiers for all the advice and tips he has given me while I've been working on this stuff.

    Due to the necessarily limited amount of Sulfite in this formulation, it does not have a long shelf life; Up to 48 hours after mixing is the limit of it’s life. It is intended for use at 95F.

    It can be used at room temperature if you either extend the development time to around three minutes, or add around 5.0g of Potassium Hydroxide with no additional development time. A color shift towards cyan, which you will have to correct for in your filter pack, may be found, if Potassium Hydroxide is used.

    The Bleach/Fixer in this formulation is diluted down for economical one-shot processing, requiring 60ml per 8x10. It is not tolerant of acid carry over from the stop bath; use the rinse between stop and blix stages.(You can probably get more than one 8x10 per 50ml.)


    RA-4 Developer -

    Distilled water at room temp 750.0ml
    Triethanolamine 6.0ml; rinse dropper in sol’n (pH around 10.4)
    Sodium Sulfite, Anh. 1.0g; from stock sol’n use 50mL
    Colour Developer 3 5.0g (The amount of CD-3 could likely be reduced, perhaps by a longer development time to cut the costs more)
    Potassium Carbonate 40.0g
    Potassium Hydroxide (room temp only) 5.0g
    Sodium Chloride 0.5g; from stock sol’n use 25mL
    Tinopal SFP brightener, if req’d 0.5g
    Distilled Water to make 1.0L

    RA-4 Stop Bath -

    Water – most of a litre
    Glacial Acetic Acid – added to water10.0ml;
    (may need to increase to 15?)
    Water to make 1.0L

    RA-4 Blix -

    Water (Room Temp) 750.0ml
    Ammonium Thiosulfate, 60% 80.0ml
    Ferric Ammonium EDTA 50% sol’n 20.0mL
    Water to make 1.0L

    Process Schedule (at 95F/35C) -

    Pre-rinse 0:30
    Developer 1:00* (or 2:00 at 70F?)
    Stop Bath 0:30
    Rinse 0:30
    Blix 2:00 (use 50mL min per 8x10)
    Rinse 3:00 (6x 0:30)
    Evaluate using viewing filters and 5000K lamp

    * The development time may need to be adjusted on a per-paper basis to obtain an ideal D-max. For example, one minute is sufficient for Fuji Super FA5 "G" surface, while 1:10 is better for Fuji
    Super FA5 "L" surface.

    Question – If the prints develop to completion, then what is the harm in leaving them in the developer and blix for longer? If the time is important, then how do I know that I have the optimal time (not too short or not too long).

    Francis A. Miniter (miniter@attglobal.net) 2001-06-28 in rec.photo.darkroom:
    The "III" generation of papers from Kodak seems to be highly sensitive to cyanic staining if overdeveloped. There is a point at which, if you leave it in the developer too long for a given temperature, the staining starts. Experiment for yourself; using various print times for a given temperature determine the maximum time you can leave the print in developer before staining starts, then determine the minimum time you can leave it in to get the same level of development on the paper. That will leave you with a range in which you can comfortably operate.

    I am currently compounding RA-4 developer according to the formula suggested by Bill Laut, and I am running it hot - over 100 degrees F. In this situation I have to pull the paper between 32 and 38 seconds to get the results I want.

    I develop RA-4 in total darkness in trays. The developer is in a water bath, and the other trays too, but not as temp critical. By the way, with a bit of trial and error, you can also develop color prints in trays, waiting about 20 seconds into the Blix before turning the lights on. Temperature control is the main issue. I use a much larger tray as a water bath and keep it warm with an immersion heater (new $100, used about half that). I find it more to my liking than a Beseler drum and motor.

  4. #4

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    If these are dusty old boxes of RA-4 and C-41 chemistry, they may well have gone bad by now. Color developers are more prone to going bad over time than are B&W developers, on average, and I'd be highly suspicious of anything that's been sitting unused since the 1990s. This is particularly true of some third-party products that ship in single bottles rather than in multiple bottles that you mix together at time of use.

    Overall, if you want to start doing color, it's best if you order some fresh chemicals. It sounds like you're near NYC, so a trip to B&H should get you what you need; or you can mail order from them (except that they won't ship a few color items, such as Kodak's C-41 bleach), Adorama, or some other outfit. Kodak chemicals are the safest bet, but they don't make small kits for most things any more. Some other companies sell smaller kits, but they're more expensive on a per-roll or per-print basis. You can also mix the chemicals yourself from raw components, but that's another can of worms; it'll definitely be simpler to start with the ready-made stuff.

  5. #5

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    Thanks for the help. Yeah its a fujimoto not fujifilm; typo.



 

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