ultrasonic agitation?

Discussion in 'B&W: Film, Paper, Chemistry' started by Sean, Apr 29, 2004.

  1. Sean

    Sean Admin Staff Member Admin

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    I saw one of those ultrasonic jewelry cleaners the other day and was wondering, what if you scaled it up and developed sheet film in it? Maybe with short bursts or something... Was wondering what might happen and if anyone has tried something like this with film :smile:
     
  2. David R Munson

    David R Munson Member

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    That's a very interesting idea. I'd be intrested to see if this is even remotely feasible.
     
  3. Thilo Schmid

    Thilo Schmid Member

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    Sean,

    it is most likely that the ultrasonic cleaner will wipe off the emulsion. However, it is a nice device for the photographer. There is nothing better for cleaning filters and ground glasses.
     
  4. Aggie

    Aggie Member

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    The cheap ones are cheap for a reason Sean. They either are big and are worn out, or they are small and plastic and don't last. They really for what they do have quite strong vibrations going through them. Just think it can blast encrusted yuck off diamonds and metals, what is to keep it from blasting the emulsion off the flim base?
     
  5. dr bob

    dr bob Member

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    I have experience with several varieties of ultrasonic cleaning equipment and Aggi and Thilo are correct. They will remove practically all the emulsion and anything else from your 4x5 leaving you with the clearest film ever (probably, depends on the power of the device).

    The working theory in developer agitation is two fold: 1. to remove the layer of spent chemicals and 2. to replace with fresh chemicals. The theory of ultrasonic cleaning is to jiggle the subject in order to physically shake off adhering particulate. These are diametrically opposed mechanisms. The bottom line is: don’t bother. Normal agitation is better.
     
  6. AllanD

    AllanD Member

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    Place your developing drum on a horizontal hi-fi speaker and connect the speaker to an amplifier. Turn up the volume and hit it with some music.

    This system allows you to employ any type of agitation theme you like. Give it some rock and roll for a grainy effect, or connect a mike and whisper sweet nothings for a more gentle, romantic look.

    Only kidding !
     
  7. mobtown_4x5

    mobtown_4x5 Member

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    Why does the machine have to be on long enough to totally remove the emulsion- how about a limited blast to shake up or distort the silver image during development- could produce some innnerestin effects, methinks...
     
  8. maxby

    maxby Member

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    Very interesting concept. Can anyone post the results of this experiment???
     
  9. Thilo Schmid

    Thilo Schmid Member

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    The cleaning effect of an ultrasonic cleaner is based on periodical contraction and expansion of the cleaning fluid. This causes so-called Kavitation Bubbles, tiny underpressure bubbles, that implode when they hit the cleaning targets. This impolsion mechanically removes more or less loose appendages. This happens sporadic. You have no real control over this process. Even a short burst or a burst at lower energy might locally affect the emulsion. Ultrasonic cleaning is a "stochastic" process. Increased duration only reduces the probability that there is still something left that could be removed...
     
  10. fhovie

    fhovie Subscriber

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    I have an ultrasonic cleaner that I use to restore antique fountain pens. It has actually cracked plastic bodies and it is a cheap one and not very powerfull. I think Nitrogen burst would be ideal but then the law of diminishing returns sets in. When I tank develop, I do rapid inversions and spins to break up the laminar flow of spent developer. It works consistantly well without uneveness or streaking. I an not sold that it can be done any better.