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  1. #11

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    I'm using AGFA microfilm EcoPos 305 for microfiche. Temp 37C
    Developer 80 gr sodium sulfite, 40 gr hidroquinone, 40 gr potassium hidroxyde and 20 gr potassium bromide. Dmax=2,50 Ok ! but time to developer is high

  2. #12
    mts
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    Look into using one of the X-ray developers. I have used DuPont X-ray developer for P3200 film and gotten a nice straight line, steep characteristic curve.
    By denying the facts, any paradox can be sustained--Galileo

  3. #13

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    Contrast greater than D-8 means a litho developer like D-9. D-11 is a less energetic possibility. Microfilm developers generally are in the ballpark. D-19, Dektol, and their like are lower contrast.

  4. #14
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    I would think that if one added a bunch of bromide to full strength Dektol and developed the heck out of most any film, you could get charcoal in snow, or at least dark chocolate in vanilla out of most any scene.
    Gadget Gainer

  5. #15
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    When I get a bit more time I'll post a faster working developer for you. The quoted time is 0.2 seconds @ 180F which by my reckoning will be more like 0.57 seconds at 37C. The quoted time for D8 is 2 minutes at 2 parts Dev + 1 water.

    The secret is no Potassium Bromide, instead a very high level of Benzotriazole.

    The formula is by C Orlando, from Phot. Sc. Eng. no idea about the contrast.

    Metol 13 g
    Sodium Sulphite (and) 80 g
    Hydroquinone 26 g
    Sodium Hydroxide 26 g
    Benzotriazole 200 g
    Water to 1 litre

    Dev time 0.2 seconds @ 180F or a more manageable 0.57 seconds @ 37C

    You'd need to experiment but dropping the bromide level in D8 and adding and increasing the Benzotriazole instead will have a huge impact on the development times. The Bromide is at such high levels that it inhibits development.

    Ian
    Last edited by Ian Grant; 03-22-2009 at 04:22 PM. Click to view previous post history. Reason: more time so added the info

  6. #16

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    Benzotriazole 200 g its correct ?

  7. #17
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    Quote Originally Posted by Paulo Roberto View Post
    Benzotriazole 200 g its correct ?
    My mistake that should be 200ml of 1% solution apologies I was rather tired last night

    There's a second formula which has the same amount, and a similar 0.2 sec dev time @ 170F or this one which uses KBR & Benzotriazole, it's much closer to D8.

    The formula is by L.S. Fortmiller, from Phot. Eng. again no idea about the contrast.

    Metol 5 g
    Sodium Sulphite (and) 90 g
    Hydroquinone 45 g
    Sodium Hydroxide 40 g
    Potassium Bromide 10 g
    Benzotriazole 1% 25 ml
    Water to 1 litre

    Dev time 1 minute @ 140F

    Benzotriazole can be substituted for the Bromide usually at around a tenth the quantity but this will vary with the formula.

    Ian

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