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  1. #1
    digiconvert's Avatar
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    It shouldn't be this easy !!

    OK I bit the bullet and tried RA-4 in trays with room temp chemistry, filtration through unicolor filters on a 'mono' head (mains to a tungsten bulb). Temp control as the water comes out of the tap.
    I then tried C-41 processing (bowl of haot water as the 'thermostat')

    I had read about the need for super accuracy of temp (+- .5deg C) and timing (I use a coltim accurate to within 30"), the need for a rotary or slot processor etc. etc. but I am getting reasonable prints and negs now (not always consistent filtration but it doesn't take much to get there). Why is it working ? Am I easily pleased ? Am I incredibly lucky ? or is colour work actually not quite the black magic some make it out to be ?
    I find it easier than PS and scanning negs.
    Some other questions
    -Would a drum make life easier or harder ? (still room temp, hand rolled)
    - Do I need to take care about the RA-4 chemicals ? (after 20 years in various labs I have skin like a rhino)

    Comments welcome

  2. #2

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    Drum uses less chemicals. It keeps them in a nice safe drum. Depending on the drum it lets you do multiple prints at the same time. Lets you turn the lights on. Downsides? Cost of the drum. Needing to dry the drum between runs.

    I wear gloves with RA-4. You should read the safety info.

  3. #3
    Ed Sukach's Avatar
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    Quote Originally Posted by digiconvert
    I had read about the need for super accuracy of temp (+- .5deg C) and timing (I use a coltim accurate to within 30"), the need for a rotary or slot processor etc. etc. but I am getting reasonable prints and negs now (not always consistent filtration but it doesn't take much to get there). Why is it working ? Am I easily pleased ? Am I incredibly lucky ? or is colour work actually not quite the black magic some make it out to be ?
    I find it easier than PS and scanning negs.
    Some other questions
    -Would a drum make life easier or harder ? (still room temp, hand rolled)
    - Do I need to take care about the RA-4 chemicals ? (after 20 years in various labs I have skin like a rhino)Comments welcome
    After a few years of processing C-41, RA-4 and E-6, accompanied by sundry mistakes in processing, I have come to the conclusion that: temperature control (both in terms of adhering to the desired temperature on the thermometer and uniformity solution-to-solution) is NOT that critical.
    Originally, when Ektachrome "home processing" first became available, the processing temperature HAD to be controlled (no slack permitted, according to Kodak) to be controlled to 75 degrees F +/- 1/4 degree. There is, first *no way* one can tell if that is happening; even the top "Laboratory Grade" Kodak thermometers were only guaranteed to +/- 1/4F; and second there is *no way* the temperature could be controlled that accurately.

    The ideal processing temperature for C-41 is 38 degrees C. The ideal processing temperature for RA-4 is 35 degrees C. I use a JOBO CPP-2 (JOBO claims a temperature accuracy, using this puppy, of +/- 1/3 degree Celsius).
    You've guessed it - the most common mistake I've made is to process C-41 film at 35C, and RA-4 at 38C.

    The results? Simply put, I can't tell one whit of difference, either by eye OR using a color densitometer. Apparently there are other factors; chemistry uniformity, film and paper characteristic variations, lighting conditions and exposure, the phase of the moon, whether or not Mars is in Capricorn ... that have a far more significant effect than does processing temperature.

    I think that the requirement of +/_ 1/4 degree F was a CYA ploy for Kodak. If anyone complained about their results, Kodak could always dodge the problem by saying... "You didn't control the processing temperature closely enough"... and they would (to a probability of 99.99999999%) be right... the processing temperature would NOT have been controlled that accurately .. but equally probably, that would not have been the cause of bad processing, either.

    A drum WOULD make processing easier. "Life"? I don't know...

    I would get the chemical advisory data for the chemistry you are using. I've used Photocolor, Tetenal, Russel, Agfa chemistry - (probably others as well) and I can't find anything super-dangerous in their compositon. I wouldn't drink the stuff, but I don't think these are any more of a concern than black-and-white chemistry, either. NOTE: This statement does NOT apply to Cibachrome P3/ P30 chemistry. That stuff, I WOULD worry about.
    Carpe erratum!!

    Ed Sukach, FFP.

  4. #4

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    Dear digi,

    Personally, I converted from drums to trays and haven't looked back. You should have no trouble getting as many prints/liter from trays as you can with drums. I use gloves but I'm a wuss.

    Neal Wydra

  5. #5
    Petzi's Avatar
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    RA-4 in trays at room temperature is OK, but C-41 I would process in a drum at the suggested temperature. I hear that C-41 is not optimal at room temperature while RA-4 is.

    I wouldn't mess with a hand rolled drum at room temperature though. That is inconvenient and awkward in my experience. Get a Jobo CPE-2 or something for films. Then you can use the right temperature.



 

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