Controlled bleaching

Discussion in 'Enlarging' started by BetterSense, Jun 15, 2011.

  1. BetterSense

    BetterSense Member

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    I know you can get spotting dyes for ADDING density to prints, where there are white spots. It's easy...you just draw on the print. But is there any nice, predictable way to bleach prints back? Say I have a black spot I want to get rid of. In my case, I have one of those construction lights that they place at roadsides in my picture, and it is not very readable. I want to lighten the lightbulbs that are 'on' so that the sign is more readable. It would be simple for me to darken the ones that are off, but is there a good way to bleach the ones that are on? Do people ever add catchlights to portraits using bleach?
     
  2. Smudger

    Smudger Member

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    You should check out iodine : a drop on a toothpick will bleach back to paper white in a few seconds.Clear the brown spot in fixer and re-wash the print.
    It's not very controllable though -kind of an "all or nothing technique.
     
  3. jnanian

    jnanian Advertiser

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    back in the day, they would do just the opposite ..
    abrade the negative to physically remove the catchlights --
     
  4. Joe O'Brien

    Joe O'Brien Member

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    I guess if you have a lot of time on your hands you could do the iodine trick and then add density back to the value you want. I've been experimenting lately with the removal of complete sections of a photograph with household bleach and a cotton wad, household bleach works great!
     
  5. eddie

    eddie Subscriber

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    You can use the bleach, from a 2 part sepia kit, or straight Potassium Ferricyanide should do the trick.
     
  6. Monito

    Monito Member

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    To solve the OP's problem, he could very carefully spot the negative. By adding density to the negative it will make his highlights (sign lights) brighter. Very hard on 35mm, easier on 8x10.
     
  7. BetterSense

    BetterSense Member

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    I considered spotting the negative, but it's a very small section of a 35mm negative.
     
  8. Marco B

    Marco B Member

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    I think you should have a look at the video linked in the first post of the thread below. Narration is in French, but that is not a problem, as the work of the female photographer in the darkroom speaks for itself. At one point, you see her working with both a brush and a running water hose to bleach back in a controlled way some to dark tones, most likely using a ferricyanide bleach (don't forget to re-fix your photo after this!). The photo is placed on a sloping angle above a sink at that point, to catch the running water. Gives some impression of how it can be done. You actually see her lighten up the white part of eyes using this method and cotton sticks:

    http://www.apug.org/forums/forum41/84315-yet-another-great-darkroom-printing-video.html

    Marco
     
  9. jnanian

    jnanian Advertiser

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    bettersense ..
    i didn't realize it was a 35mm negative ..
    you could make a master print the size you want the final print to be
    and contact print a paper negative from it ( no writing on the back + FB paper )
    work on the paper negative with pencils and a knife &C and graphite dust ..
    and then contact print a positive print from it. i have retouched negatives for a while
    but nothing smaller than 4x5, mainly because the enlargement factor ... and if you aren't
    really good it sticks out like a sore thumb ...

    - john
     
  10. Bob Carnie

    Bob Carnie Subscriber

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    Ok so that answers my question to you.

    People do use red coccine on larger negs, to lighten areas , this method goes back to the late 30's or even further back.
    I am printing a portfolio right now that has a few images damage at time of exposure , creating black scratches and spots.
    I have made the prints to my best ability, but not selenium toned, I am sending them to a retoucher in town who specializes in this, She will bleach back the spots, refix the image , send the image back to me , I will selenium tone the print and wash as all the rest of the portfolio, but send the print back to her for final retouch. Lots of work , she is the best I know and I trust her work.
    The specifics of chemical formula she uses I cannot speak.

    I have spot bleached with pot F , many times to bring up areas, you need to be good and fast and make sure you fix. I will do this on certain images where I feel regular printing just isn't enough, be prepared to use the round bucket alot so print extra prints.

     
  11. jordanstarr

    jordanstarr Member

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    I've done very much what you're trying to do and my approach is Potassium Ferricyanide diluted to regular bleaching strength (which I just measure out by wetting a q-tip, dip it in the potassium ferricyanide and add 75ml of water. If I were you, I'd use a very thin brush, bleach the areas you want lightened up, wait 3 seconds, dip in the fixer and repeat until you're reached your desired lightness of your highlights. You can spot in the density around it to bring out the text in the sign. That's what I would personally do and it has worked well for me in the past. You need to blow the fixer off when you're bleaching as it will run and then you won't get that density back. It's a careful and tedious process, but it works like a charm when you can nail down the technique.
     
  12. Gerald C Koch

    Gerald C Koch Member

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    ... and it also destroys the emulsion. Sodium hypochlorite (bleach) is a very powerful and non-specific oxidizing agent which also attacks organic material. Your prints may look good for a awhile but it only a matter of time before they are affected. This is why gentler oxidixers like ferricyanide are used in photography.
     
  13. Marco B

    Marco B Member

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    What does the highlighted sentence mean? I don't understand it?? "blow off fixer?" :confused:
     
  14. jordanstarr

    jordanstarr Member

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    ...hold the area of the print you want to bleach over your arm, flat and blow the spot you want bleached. Don't just hold it up and start going 'cause the wet fixer will do two things when bleaching: 1. make the bleach run on areas you don't want it to and 2. resist/stop the bleaching process. When I do area bleaching, I sometimes leave the fixer on as the resistance of the fixer will slow down the quickness of the bleach setting in. But in this case, you're working with such a small area that the bleach in the tip of the brush will be rendered useless by the time it hits the print. Hope that helps.
     
    Last edited by a moderator: Jun 19, 2011
  15. Gerald C Koch

    Gerald C Koch Member

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    Years ago when people wrote with fountain pens (remember fountain pens) they sold little kits to correct what was written. There were two bottles in the kit. The first contained sodium hypochlorite to bleach the ink and the second contained dilute acetic acid to stop the bleaching action. If you didn't use the second solution the bleach chewed up the paper.

    Don't use hypochlorite with a natural bristle brush as the bleach will destroy the bhush. If you read the Chlorox label it says not to use it with wool garments.
     
    Last edited by a moderator: Jun 19, 2011
  16. scheimfluger_77

    scheimfluger_77 Subscriber

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    There use to be a two spotpen combination that provided a bleach in one and neutralizer in the other. There is something similar at Freestyle, can't post the link. Tim Rudman also talks about local bleaching of prints in his Master Printing Course book. That discussion is not focused at spot removal, but the principles are the same. A weak solution of Pot. F. bleach in combination with a 00 or 000 brush works well. I forget what the neutralizer is but the idea is to work slowly and not bleach down all at once, just like spotting white dust spots. I tried spotting a negative once, and will never do that again.

    Steve
     
  17. Mike Wilde

    Mike Wilde Member

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    I use an iodine based bleach called R14. It is an A+B. I found the formula in a 70's era Koadk book called 'Bigger and Better Enlarging" or something like that. I have two small 10mL bottles worth dedicated to this bleach, and I mixed it perhaps 3 years ago, so the formula is not at hand right now. PM me if others are interested. You look at prints while in the fixer. Dry the black spot locally (I usally use my fingers on front and back of the print first, then dab with a paper toel to gett he fixer off the surface.

    My technique with this stuff is to combine two drops using an eye dropper (rinse between A and B bottles) into a small cup, swirl a bit, and then dip the skinny end of a toothpick in. Tap the toothpick to shake off excess liquid, and touch the spot. It will fade to white in under 30 seconds, usually faster. Drop the print back into thefixer for a while, and wash as normal. Once dry, retouch the white on the print to blend into the surrounding area.

    Yes, pencils can correct clear spots in 4x5 negs, but it is hopeless in 35mm negs to try to hunt them down.
     
  18. Mike Wilde

    Mike Wilde Member

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    I looked the formula up, and my error, no iodine. That was for a fixer wash test.

    I make it up in MUCH smaller quantities, but here is the formula per litre:

    R14A water 700mL 50-60C
    15g Thiorea
    700g Hypo
    water to 1L

    R14B 700mL 50-60C
    150g Potassium Ferricyanide
    water to 1L
    Store in brown glass ina dark place to make the B last.

    Mix 2A to 1B to 2 water for speckle bleaching. More dilute for local bleaching .

    Wash after use.