J D Photochem RA-4 Kit

Discussion in 'Color: Film, Paper, and Chemistry' started by Stew, Nov 11, 2005.

  1. Stew

    Stew Member

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    Hi,
    Has anyone used the RA-4 print processing chemical kits sold by JD Photochem in Quebec? The prices seem very reasonable.

    I was also wondering what temperature range these chemicals can be used at.

    Thanks in advance,

    Rob.
     
  2. Nick Zentena

    Nick Zentena Member

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    Assuming things haven't changed.

    1) The inscructions claim 36C I think. If you want I'll check later. It's higher then normal RA-4 but not much higher. At least that's what the inscructions claim. The times are also longer then normal. My guess is he went with higher temps/times to make sure people mucking around at home got good results even if they weren't keeping a close eye on temps/times. Maybe somebody else can comment on this but my understanding is the longer times won't hurt anything.

    2) The prices are even better when you look into the yield -)

    3) Even better if you do a prewash for the first step.

    I've had no problems with them using a couple different Kodak papers.
     
  3. Ed Sukach

    Ed Sukach Member

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    THe "normal" - "usual" is a better description - temperature for RA-4 processing is 35 degrees Celsius ... one degree difference? What are the times recommended?
     
  4. Nick Zentena

    Nick Zentena Member

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    Pulled out the chemical stained info sheet

    "For best results keep all solutions between 36 & 37 degrees centigrade

    1:20 developer
    1:20 blix
    1:30 wash

    "

    It's a couple of degrees warmer and that's longer isn't it? I've always thought he did that to make sure those with lax temp control still got good results.

    Claimed yield is 200 8x10s for the 1 US gallon kit. I find the real yield is higher. Much higher if I do a prewash first.
     
  5. Stew

    Stew Member

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    Attention Nick Zentena : Lower temperature possible?

    Nick , or anyone else who would like chime in;can these chemicals be used at a lower temperature, say 34.5 to about 35 Degrees C by increasing development time? This is about as high as my temperature control goes-(fish tank heater).Thanks.
     
  6. Nick Zentena

    Nick Zentena Member

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    35? You'll be well within tolerance. I actually think John [the old owner of JD ] played it safe by saying 36-37C. I remember asking him the same things and he said "Do your best" -) I forget the name of the new owner but when I've talked to her she has seemed to know her stuff. Email/phone her and ask.

    Is your fish heater adjustable? Mine is. Offically it's limited to 34 or so to. But it's got an adjustment. The adjustment is supposed to be to correct the temps so they match the dial. Nothing stops you from doing the opposite. IIRC when my dial reads 32C it's actually set for 38 now.
     
  7. Photo Engineer

    Photo Engineer Subscriber

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    The Kodak RA4 chemistry can be used to 68 deg F (20 deg C) but they do not advertize that fact. I use it there all the time.

    There is a bias on the yellow blue axis as you decrease temperature. Otherwise the pictures look great.

    Don't forget to use 10' or longer wash times at that low temperature.

    And don't pay an arm or a leg for 'low temperature kits'. Also, use no kits for paper that contain CD4. This is bad for dye hue and dye stability.

    PE
     
  8. gbroadbridge

    gbroadbridge Member

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    PE, just for info, the Patterson RA4 stuff works fine at room temperature (20 C).

    I've never done RA4 at C41 process temp and see no reason to start. I do all my RA4 in dishes at room temp using latex gloves.

    Not a proven fact, but I believe the solutions last longer at this temp. I'm still using a dev I mixed on 26 December 2004, and I just replenish it every 20 prints or so. I store the dev in air tight bottles and give them a squirt of butane.

    The RA4 blix (also mixed on 26 Dec 2004) has made the bottle go relective, like a silver coating, but I just give it a shake, let some air in, give it another shake and it works okay. Last time I replenished the Blix was in March so before the next print I'll add some fresh blix.

    I see no need at all to throw away chemistry no matter how old, as long as it works.


    Graham.
     
  9. Photo Engineer

    Photo Engineer Subscriber

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    Graham, some of the kits advertized as working at RT either attach a premium price to the kit or use CD4 as developing agent. The former is a ripoff as they work there regardless of price, and the latter will change dye hue and dye stability for the worse.

    That is my only concern.

    PE
     
  10. Photo Engineer

    Photo Engineer Subscriber

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    Graham, I know this sounds pretentious, but I formulated the original Kodak blix, date: 10/1966 and it was called Blix 1066 for several years internally. I sent the first formula transmission letter on it to manufacturing for use with Ektacolor paper T1970. So, I probably know more than anyone around about this particular chemistry.

    My point is, if you or anyone needs help on bleaches, blixes or fixes, give me a shout. I'm here! I've also done extensive work with bleaches and fixes for film as well as blixes for papers, and so I feel that I can speak authoritatively on the subject.

    I've also studied developer formulation effects on color paper, and find that all developers and papers do not interact well at all temps. This is a real problem, as EK and Fuji for example only run release tests at one temperature with one developer. I have found that off brands can vary considerably due to the differing salts that they use for economy purposes. EK and Fuji use 'authentic' chemistry that is cross checked between the companies to insure compatibility. Some of this chemistry is omitted due to cost considerations by second tier mfgrs. Be forewarned.

    So, I feel it is a matter of years of experience rather than pretention. If I can help, I will. I'm here.

    PE
     
  11. gbroadbridge

    gbroadbridge Member

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    Hi PE,

    You're already on my shortlist in relation to anything chemistry related for photography. I just wish I knew enough to ask more :smile:

    Perhaps you could tell me why my bottle of Blix has gone reflective silver so I can no no longer see the level in the bottle. The entire (plastic) bottle has turned silver.

    Does this indicate that maybe the blix should be replaced as it has absorbed enough silver to plate the bottle? As discussed in another thread, I replensish my blix, by throwing out (say) 250ml and adding enough to make up the volume again. Volume is normally 600 ml.


    Regards
    Graham.
     
  12. Photo Engineer

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    That blix may not be exhausted entirely, but there comes a point of diminishing returns. I would throw it out and start over. Clean the bottle well too, as the silver film will start to react with the fresh blix. Use dichromate in sulfuric acid to clean the bottle. That should clean off the surface. If there is sulfur on the bottle surface as well, use strong lye to clean that off. Make sure you don't mix the sulfuric acid and lye. That will spatter and boil. Wash well between treatments of these two (lye and dichromate/acid) as they are incompatible.

    PE