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Thread: Midtone Machines - Automatic Film Processing Machine

  1. #11
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    Re: Midtone Machines - Automatic Film Processing Machine

    Quote Originally Posted by ic-racer View Post
    How do you clean it after use? I'd think that would be the one thing were improvement over existing film processors could be achieved. In a "Lift" Jobo, each bottle needs to be rinsed with water after use, and 1 liter of water needs to be poured through the lift. With the Jobo, this additional step adds 30 seconds to my day. Can your device improve on that?
    To be clear to those who are not familiar with the Jobo processors, the processor needs an after-wash only if you don't do the film wash on the processor. If you do, that takes care of both the film and the processor. (The bottles do get a brief rinse as part of my clean-up afterward.) If for some reason one couldn't conveniently do the wash on the processor, that would be a strike against it for my purposes.

    Getting back to Andrew's additional question, I use the Jobo Expert drums. A key benefit of the Jobo drum system for some of us is the ability to accommodate a wide range of sheet film sizes other than 4x5, from 2.25x3.25 all the way to 20x24. That said, I think it's likely that 4x5-only users are the largest subgroup within this small market.

  2. #12

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    Re: Midtone Machines - Automatic Film Processing Machine

    Do the JOBO expert drums show any issues with chemistry not getting to the back of the film? I've used the 'taco method' for developing my 4x5 sheet film with a hair band to hold the film and there was a mark where the band was touching the back of the negative and the anti-halation layer didn't go away (it wasn't noticeable in the scan at least). I do like the 'mail tube' idea of holding film, specifically because it can hold a wide variety of film sheet sizes without modification.

  3. #13
    Peter De Smidt's Avatar
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    Re: Midtone Machines - Automatic Film Processing Machine

    Nope. No issue with film back. The drums are designed to allow solution to reach the back.
    “You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
    ― Alexander Den Heijer, Nothing You Don't Already Know

  4. #14
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    Re: Midtone Machines - Automatic Film Processing Machine

    What Peter said. A key point about the 3004/3005/3006/3010 drums is that the "wells" in which the film is inserted are not strictly cylinders - they are slightly barrel-shaped. The structure of those drums is actually quite complex - the housing is hollow and has slots to allow water from the processor's tempering bath to enter and create an internal water jacket to further facilitate temperature control. The complex construction is part of why they are so expensive, but also an important part of why they work so well.

    See also this thread:

    https://www.largeformatphotography.i...made-Jobo-3005

    A pure cylinder shape can work well for develop/stop/fix of the emulsion, but it will often mean that the film requires separate clearing and wash steps outside of the processor after that.

    The big 3062 and 3063 drums are just overgrown print drums, hollow shells with ribs molded into the internal surfaces of the shell to allow fluid behind the sheets. These have worked well for me in developing ultra-large sheet film sizes with standard metol- or phenidone-based developers, but the ribs have been reported by some to cause artifacts when pyro developers are used.

  5. #15

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    Re: Midtone Machines - Automatic Film Processing Machine

    New blog post up, details of a survey I put out a month or two ago:

    http://midtonemachines.com/news/a-slice-of-pie-charts/

    There's also a link at the bottom of the past to the survey if you want to make your thoughts heard. I developed two sheets of 4x5 Ektar using the taco method this morning, development went fine and the negatives look good but the hair bands came off inside the tank at some point and I got quite a few scratches. I'm making sure I have constant incentives to move this project along!

  6. #16
    ic-racer's Avatar
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    Re: Midtone Machines - Automatic Film Processing Machine

    Quote Originally Posted by AndrewBurns View Post
    Thanks for the replies so far, keep 'em coming.



    One of the inputs to the machine would be water for rinsing/flushing (tap or deionised water depending on you preference). After the process is complete the machine would automatically clean itself by flushing water through the dev tank and pump. It's designed to suck in chemistry from whatever bulk container you'd like which wouldn't ordinarily require flushing after each use however if you wanted to change chemicals around there will be a full cleaning cycle that would flush water through all channels. All of these features would of course be fully automatic so you wouldn't need to do anything, just come back when it's finished.
    That would be great. I was just using my Jobo last evening and I can't see doing it without the darkroom sink and tempered/filtered water to prepare each bottle of chemistry, then to rinse each bottle and graduate for the next use. For example, rinse bottle, rinse graduate, add concentrate to graduate, dilute with filtered water from the darkroom sink, rinse graduate, repeat with next bottle, etc. If somehow yours could automatically dilute the concentrate solutions too, that would really make it 'plug and play.' The important thing being dilute solutions won't last, so the machine needs to be in constant use like almost every commercial machine already in existance, whereas the concentrated solutions last years.

    As I think about this I realize my wife's clothes washer has the ability to accept powder or concentrate. It automatically dilutes either one. That is another interesting idea, that your machine could dilute a powder too!

  7. #17
    Tin Can's Avatar
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    Re: Midtone Machines - Automatic Film Processing Machine

    Have you studied X-Ray processors both for transport, dilution baths and concentrate bottles?

    https://www.largeformatphotography.i...=1#post1509409
    Tin Can

  8. #18

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    Re: Midtone Machines - Automatic Film Processing Machine

    Quote Originally Posted by ic-racer View Post
    That would be great. I was just using my Jobo last evening and I can't see doing it without the darkroom sink and tempered/filtered water to prepare each bottle of chemistry, then to rinse each bottle and graduate for the next use. For example, rinse bottle, rinse graduate, add concentrate to graduate, dilute with filtered water from the darkroom sink, rinse graduate, repeat with next bottle, etc. If somehow yours could automatically dilute the concentrate solutions too, that would really make it 'plug and play.' The important thing being dilute solutions won't last, so the machine needs to be in constant use like almost every commercial machine already in existance, whereas the concentrated solutions last years.

    As I think about this I realize my wife's clothes washer has the ability to accept powder or concentrate. It automatically dilutes either one. That is another interesting idea, that your machine could dilute a powder too!
    Can your washing machine dilute from any quantity of powder/concentrate or do you have to add the right amount for every load? Currently the machine doesn't have the capability to mix solution internally (it wouldn't have the accuracy required) however I know exactly how you could do it and I could imagine it being an optional add-on potentially. Basically it would require a small preistaltic pump inside the machine with an encoder for concentrate, that way the machine would know exactly how much volume of concentrate it had pumped and could make up a mixture with water of any reasonable concentration.


    Quote Originally Posted by Tin Can View Post
    Have you studied X-Ray processors both for transport, dilution baths and concentrate bottles?

    https://www.largeformatphotography.i...=1#post1509409
    I haven't really looked into x-ray film machines, I would imagine they're generally larger roller transport machines?

  9. #19
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    Re: Midtone Machines - Automatic Film Processing Machine

    OP, your job is research.
    Tin Can

  10. #20

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    Re: Midtone Machines - Automatic Film Processing Machine

    New blog post is up:

    http://midtonemachines.com/news/meat...fluid-diagram/

    This time I've shared the fluidic system diagram and gone into some detail about how the chemicals move around the machine. I've been getting lots of prototype parts in over the last few weeks and I'm close to 3D printing the development tank components so I can do fit and functional checks before committing to vacuum resin casting a batch of 10.

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