Reversal processing: when can I turn the lights on

Discussion in 'B&W: Film, Paper, Chemistry' started by Marco Buonocore, Feb 13, 2012.

  1. Marco Buonocore

    Marco Buonocore Member

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    I am about to make my first attempts at reversal processing; I plan on doing sheet film. I process on hangers in a deep tank.

    Processing is done in a film changing room, and the ventilation is... well... it's not ventilated. At what point in the process can I take the film out into room light?

    I will be following the procedure listed in the 3rd edition of the Darkroom Cookbook.


    Thanks!
     
  2. Ian Grant

    Ian Grant Subscriber

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    Once you've done the reversal exposure then in theory you can leave the lights on. In practice as long as you're not workingt in sunlight there won't be a problem.

    Ian
     
  3. Mike Wilde

    Mike Wilde Member

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    Or, if you are reversing chemically, after the reversing bath. I usally wait until after a water rinse that follows the reversing bath for my DIY process. I use a tiny bit of an obscure compound I bought from JD Photochem prior to thier closing for my B&W reversals called sodium borohydride. I prefere it to tin based ones, which I regard as toxic big time.
     
  4. Marco Buonocore

    Marco Buonocore Member

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    Thank you Ian.

    Mike: I plan on starting with re-exposing the film with light. 150w bulb seems to be what's recommended. I may explore chemical reversal, but not until I get the hang of things. What would you say the advantages of chemical reversal are, with the obvious exception of the fact that you don't have to take the film off the reel?

    Thanks!
     
  5. Bob-D659

    Bob-D659 Member

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    You can leave the film on the reel, worked just fine 40+ years ago for Anscochrome and b&w reversal with a light bulb, no reason it won't work these days.
     
  6. Athiril

    Athiril Subscriber

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    You dont have to take the film off the reel!

    And damage it (esp with re-threading while wet!) handy for long rolls and multiple rolls.
     
  7. Marco Buonocore

    Marco Buonocore Member

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    Great news! I'm useless at loading stainless reels. I prefer the Patterson plastic ones, but they're impossible to load when wet. Thanks!
     
  8. Jim Noel

    Jim Noel Member

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    To load plastic reels when wet, hold them and film under water.
     
  9. dr5chrome

    dr5chrome Member

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    ..wait to go light until the next step after the 2nd development.

    dw
     
  10. Oxleyroad

    Oxleyroad Subscriber

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    I used to unload the film from reels, and reload under water. It did help prevent damage to the emulsion. I don't bother unloading now as I have found there is no need.

    I use a 150w flood light in the dakroom and I open the developing tank once the clearing bath is in. After the clearing bath time is up, and I have the film washing in water, I lift the film reels out of the tank and roll around to get light to every part of the film surface.
     
  11. doublenegativeseb

    doublenegativeseb Member

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    Most of the information I can find on the web regarding re-exposure is really confusing. However i've discovered that as long as you've fully bleached out your silver image, it's almost impossible to over expose on the re-exposure. A 60 W bulb at a distance of 1 meter for 60 Seconds is sufficient.

    I hang a lightbulb above my sink, remove the film from the spiral and make sure bothe sides of the film receive light for a total of around 60s. I have had good consistent results with FP4+, Delta 100 and just today with Rollei Blackbird (very clear film base). The fun thing about this process is that it can be done with paper too - here's a direct positive on Forte Bromofort http://www.flickr.com/photos/sebsussmann/6885723103/ but it works well on Foma papers too.