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Thread: 8x10 Development in tray - How to know the time

  1. #11
    Vaughn's Avatar
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    Re: 8x10 Development in tray - How to know the time

    I use an old beat-up Gralab timer. I turn off the buzzer as it usually sends me thru the ceiling and since I do not listen to music I can hear it shut off at the end of the time. This way I can keep it down below the counter with the trays on it (developing 11x14 negs)...no problem with the glow that way.

    Gad -- last thing I want to hear is my own voice!

    I can develop five 8x10s at once in a Jobo Expert Drum -- I wash each neg in its own 8x10 tray...exchanging the water about 5 times each, and a little aggitation between water changes.
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  2. #12

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    Re: 8x10 Development in tray - How to know the time

    Hello,

    Thank you ALL for all those tips !

    But concerning the washing....

    I understood that changing 5 times the water will be enough but how many times the sheet needs to be in the tray between each exchange ?

    And do we need to do some agitation or just leaving the sheet in the tray is enough ?

    Thanks for the clarification.

    Dom./

  3. #13

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    Re: 8x10 Development in tray - How to know the time

    I use an workout interval timer app on my phone. It's entirely auditory, so I can leave the screen off. Just set the intervals for each step of the process and let it go.

  4. #14
    David Schaller
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    Re: 8x10 Development in tray - How to know the time

    Quote Originally Posted by Rscaboy View Post
    Hello,

    Thank you ALL for all those tips !

    But concerning the washing....

    I understood that changing 5 times the water will be enough but how many times the sheet needs to be in the tray between each exchange ?

    And do we need to do some agitation or just leaving the sheet in the tray is enough ?

    Thanks for the clarification.

    Dom./
    I transfer the negative(s) to a filled 11x14 tray under a tap dribbling fresh water in slowly. I dump the whole tray and refill a couple of times, while I do other clean up, for about 15 minutes with Pyrocat negatives. Id do the same with other developers too, just to be sure the fixer is washed away. Then photoflow and hang to dry.

  5. #15
    Vaughn's Avatar
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    Re: 8x10 Development in tray - How to know the time

    Once we get the surface fixer washed off in the first set of quick rinses, we depend on osmosis to draw out the last of the fixer from the emulsion. If there is no water movement, the concentration of the fixer in the water next to the emulsion increases, slowing down the rate the fixer leaves the emulsion. Same problem leaving two sheets of film together...no fresh water for the fixer to diffuse into from the emulsion...which is why I put one neg per tray...less chance of scratching and the entire surface of the emulsion keeping in contact with the water. Occasional agitation will disperse any fixer next to the emulsion, and you are good to go.

    But then, I rinse between each changing of the water of each tray, also. Habit.
    "Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China

  6. #16

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    Re: 8x10 Development in tray - How to know the time

    Quote Originally Posted by Vaughn View Post
    If there is no water movement, the concentration of the fixer in the water next to the emulsion increases, slowing down the rate the fixer leaves the emulsion.
    Yes, some agitation shortens the suitable washing time a lot.

  7. #17
    Louie Powell's Avatar
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    Re: 8x10 Development in tray - How to know the time

    The traditional solution to the timing problem is to use a timer with phosphorescent hands - that is, hands that are painted with a material that emits a soft glow in the dark. GraLab is the classic timer for this purpose - don't know if they are still being made, but there are lots of them around.

    Phosphorescent paint is activated by exposure to light, and then emits a soft green glow for a number of hours after the light has been turned off. That glow is too dim to affect film emulsions, especially if the timer is placed several feet away from the developing tray.

    You can purchase phosphorescent paint in craft stores to refresh the paint on older timers.

    You can also use a large diameter clock (such as might have been used in office applications) - remove the front cover and paint the second hand with phosphorescent paint. In that approach, you have to keep track of the number of rotations of the second hand, so to really have to focus your attention on what you are doing - no conversations while developing film!

    There is another approach - development by inspection. This requires that you have a dark green safelight. You develop normally, using whatever means you have to time agitations. When you think the film is nearing completion, you briefly turn on the green safelight to inspect the film. People who are practiced at this approach can tell when development has been completed, but it does take some trial and error to acquire that skill.


    As to washing - the traditional approach is to put the negative in a tray and allow a slow stream of water to run through the tray for a hour or so. That uses a lot of water. A better solution is to put the negative in a tray (face up), cover the negative with water (it's not necessary to completely fill the tray), let it soak for a few minutes while agitating gently, dump the water and repeat the process. This approach is also used with prints - negatives are easy to wash compared with fiber-based prints because with prints, fixer is trapped in the paper fibers. David Vestal did extensive testing and showed that it's just as effective as running water, but wastes far less water..

  8. #18

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    Re: 8x10 Development in tray - How to know the time

    Quote Originally Posted by Louie Powell View Post
    There is another approach - development by inspection. This requires that you have a dark green safelight. You develop normally, using whatever means you have to time agitations. When you think the film is nearing completion, you briefly turn on the green safelight to inspect the film. People who are practiced at this approach can tell when development has been completed, but it does take some trial and error to acquire that skill.
    A safe development by inspection was made by Yousuf Karsh, he used Kodak products of the era to desensitize the emulsion so a safe light could be used like with ortho film. Kodak produced an special run of desensitizing solution for Karsh after they had discontinued the product.

    Today, after inspection is made we cannot extend much the development, newly exposed (fogged) crystals will start to develop after induction time (around 1 min?) building fog.

    Also I guess that today we can do the inspection with an IR night vision device (if it is not an IR sensitive film, not many are).

  9. #19
    jp's Avatar
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    Re: 8x10 Development in tray - How to know the time

    I'm even more luddite... I have a gralab 300 which doesn't glow much. I keep a towel over it when not in use so it does not charge up much. It makes a little bit extra motor noise as it goes past 45s.. Probably got dropped at some point. If I don't hear it, I can feel where the second hand is. I can also feel the zero and minute bumps and know how many minutes left by how many bumps till it reaches the minute hand.

    I don't use the gralab 300 for anything else. For other things, I prefer digital timers.

    If you visit someone else's darkroom and they have a gralab 300, wait till they are not looking and turn the buzzer on. Next time they use, it will really wake them up instead of a gentle click.

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