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  1. #1

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    E6 3 bath Processing in Paterson orbital tank

    Hi - I have almost got my routine set up to process 5x4 B&W film in a Paterson Motorized Orbital tank with Pyro and get repeatable results.

    Before the summer is finished I would like to try some E6 colour transparency film, Probably Fuji and develop in the orbital tank by using a three bath process like the Tetenal COLORTEC E6 Kit.

    The only problem I can see is that of temperature control as I cannot put the orbital tank in a tempered water bath as I have done before. Has anyone tried this? and are there any other problems I haven't foreseen?

    I should state that I ran a small E6 hand line some years ago so I have a reasonable idea what to do.

    Thanks in advance

    nn

  2. #2
    Usagi's Avatar
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    A very old topic, but interesting so I put some live on this =)

    I too have Orbital and have did C-41 without problems. But C-41 developing time is so short.

    I am wondering... Orbital is designed for RA-4 process and the manual comes with a calculator which tell how warm (hot!) should developer be when taking account to the air temperature.
    So idea is to put warm developer and during process it cools down. Perhaps belowe normal processing temperature.

    If that kind of approach works with RA-4 - and I think that I've read something similar about C-41, then how about E-6?

    Could even orbital give good result if first developer is a bit warmer than normally (around 40 degree celsius) and in the end of the process, it's one or two degree belowe normal 38 degree?
    If developer cools down somewhat linearly, then it averages to 38 degree celsius.

    Right?

  3. #3
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    Averaging works given that the maximum deviation is not too high. Probably 40...36 averaging to 38 works "well enough" for most people.

    But there is an another issue, namely that it's more difficult to control the cooldown repeatably than to continuously control the temperature. The cooldown rate depends on so many factors such as the volume of solution, room temperature, agitation, etc. With room temperature deviations from 22 degC in winter to 30 degC in summer, I would not trust the temperature averaging very much. (Specifically, AFAIK, the thermal energy loss is directly proportional to dT so if the developer drops from 40 C to 36 C at 22 C environment, it will drop from 40 C to 38 C at 30 C environment. A big difference.)

    Try it first with water, using a thermometer known to react quickly, taking a reading every minute.

  4. #4
    Diapositivo's Avatar
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    Jukka, the only critical temperature in E-6 is that of the first developer bath. All other baths are "to completion" so if you are at 36°C instead of 38°C no problem, just prolong treatment. You basically cannot "overtreat" unless you try very hard.

    That applies mainly to one-shot chemistry. If you use chemistry only once (or maybe twice at short interval) you don't worry about oxidation of chemistry and you can have it swirl a bit more in the tank. (If you reuse chemistry many times, then minimization of oxidation is a concern, and rotative processor don't help reducing it).

    The temperature of the first bath is crucial. If your "cooldown time curve" is not repeatable you risk to have inconsistent developing results.

    The first development of E-6, first one-shot use, lasts generally for 6:30 to 7:30 minutes, so your (only) problem is to device a system to keep the first bath chemistry near 38° for those few first minutes.

    I don't know the Paterson Motorized Orbital tank. If it cannot be put in contact with warm water, maybe you can find a totally manual solution, keeping the tank in warm water and making manual inversion - agitation, more reliable. You obviously have to be very rigorous in your agitation - inversion pattern. I would also presoak film twice with water at treatment temperature to properly warm up film and tank as already advised in this forum.

    Fabrizio
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  5. #5
    hrst's Avatar
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    I remember that someone heated Jobo tank with a nearby tungsten bulb. The black plastic absorbs light and heat well. The correct wattage and placement is crucial, but once you find it, you may be able to slow down the cooldown considerably, lessening the effect of variability. On the other hand, while you try to eliminate some variables with this kind of method, you get new ones such as the placement of the lamp and how long before you put it on etc. If you want to try it, as a starting point I would use a 75W reflector bulb at 30 cm distance put on a minute before pouring the FD in....



 

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