help with contact printing

Discussion in 'Contact Printing' started by loman, Oct 10, 2007.

  1. loman

    loman Subscriber

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    Hello Everybody
    At the moment I'm contact printing with the help of my durst m800 enlarger as a light source. I still use the 85 unicon condensor but for the moment has put a piece of heavy paper on top of it to diffuse the light but with the lens off.
    I want to get the most out of my contact prints using as diffused light as possible, and still keeping it simple. My darkroom is very small (aprox 1.5 squaremeters) So I'll have to use my m800 as a light source. Now my question is, what is most effective to get diffused light. Should I use the lens to get more or less light or not (does the lens direct the light?), should I still use the condensor with a diffuser above it or should I discard the condensor all together. Also what makes the most effective difusing device between the light bulb and the paper, frosted glass?
    Any input is greatly appreciated!
    Best Regards
    Mads Hartmann
     
  2. DougGrosjean

    DougGrosjean Member

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    May or may not help you, but when I started doing contact prints I bought a small lamp and a 7.5 watt bulb. I put the contact printing stuff on the floor, aimed the light at the ceiling (in the bathroom) and bounced it off the ceiling tile. HTH. - Doug
     
  3. David H. Bebbington

    David H. Bebbington Inactive

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    I personally would set up the enlarger as if you were making an enlargement, i.e. with the lens fitted and focused. This way you can be sure that the light is even. Any diffusion I would apply immediately on top of the plain glass which you presumably are using over your negative and paper. One cheap material I have used for diffusers is white opal PVC, sold in supermarkets as a kitchen cutting board. This is very diffuse and very even but cuts the light by only 1 stop. White Perspex (Plexiglass) would be fine too.

    Regards,

    David
     
  4. loman

    loman Subscriber

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    Thanks for your replys guys.
    David your idea sounds very good.
    I think I'll go with that.
    Just for the fun of it, can you explain to me why you would put the diffusion device after the lens (in the chain from light bulb to print so to speak) and not before it. What difference does it make.
    Best Regards
    Mads
     
  5. wclavey

    wclavey Member

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    I have been using sheets of mylar cut from a roll which I purchased from the local camera shop... I'm not sure what it is sold for, but it is great as a diffuser. Each sheet has about 1/2 stop reduction, so I have created some "neutral density" filters by taping together 2 and 3 8x10 sheets. So I have a 1/2 stop, 1 stop and 1 1/2 stop filter that I can lay on top of the contact printing frame based on the density of the negaitve. It is easier to make smaller changes in expose thsat way than constantly adjusting the time. The mylar is sold with a name something like Lumilux (?) - - could be wrong about that - - but I'm sure someone here will know better.
     
  6. haris

    haris Guest

    I use Paterson proofers, enlarger as light source. As I use colour head (with variable contrast papers), I use mixing chamber, lens, and negative carrier for 35mm or for 6x7 (depend what was mounted on enlarger from last printing session). I raise enlarger's head just enough to cover all area of proofer. Focus lens as for normal printing, set aperture on f11, remove all fiters (set all filter dials to 0), and for me and these settings, 10 seconds of exposing is what I use.

    When use condenser head, I do all the same, that is, leave condenser, lens, negative carrier from last printing session and make contact proof at procedure like above.
     
  7. juan

    juan Subscriber

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    I don't think you need diffused light to make contact prints. The purpose of diffuse light in enlarging is to eliminate the Callier effect. You don't have that effect in contact printing because the negative and paper are in contact with one another. This is not to say that you can't use diffuse light, just that it doesn't really accomplish anything over a condenser enlarger, so long as you raise the condenser head far enough to be sure you are getting even light across the negative.
    juan
     
  8. haris

    haris Guest

    Oh, boy, OP talked about contanct printing, not contact proof sheets...

    Sorry, my error...
     
  9. JBrunner

    JBrunner Moderator Staff Member Moderator

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    An enlarger is a great point source for contact printing. The only thing diffusing it will accomplish is to lower the output, and eliminate any spots from giant dust on condensors, assuming you could focus them. I'd rather clean the condensor. If your enlarger is so out that the light needs to be diffused to be even, well, that could be... I've had one like that :smile:

    If you need to slow it down, stop down the lens and/or raise the head.
     
  10. jnanian

    jnanian Advertiser Advertiser

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    great advice!

    unless i am printing with slow paper ( azo )
    i use an enlarger, stop the lens and raise the head --- works perfectly.
     
  11. wclavey

    wclavey Member

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    It also removes scratches that may be in the glass of your contact printing frame. When I first started contact printing my 4x5 negaitves, I was using the ceiling light in my small 1/2 bathroom as my light source and used the diffusion screens I described above to control the amount of light. But then I switched to a 7 watt light source about 3 feet above the toilet seat top and eliminated the diffusion screens ... and started getting scratches in all my prints... surprisingly all in the same place, yet I couldn't find any scratches on the negatives. Thats when it dawned on me that the diffusion screen layers on top of the frame were eliminating the scratches in the glass.
     
  12. JBrunner

    JBrunner Moderator Staff Member Moderator

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    True. I had an old contact frame with scratches and pits that caused similar problems. A diffusion screen directly over the frame would send light under the scratches and minimize or eliminate them. Instead, I just had a new piece of regular glass cut, it was something like $3 bucks. As long as your springs are strong you shouldn't have problems with regular glass, but I have heard of some persons in humid areas where newton rings are more prevalent using a lightly frosted glass that still lets them see the neg. I wonder if that awful no glare framing glass would do the same thing? I would have trouble with a diffusion over the frame, as then I couldn't see to dodge and burn.
     
    Last edited by a moderator: Oct 15, 2007
  13. wclavey

    wclavey Member

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    I switched to using just a piece of new 1/4 inch glass, but I really liked using the contact printing frame, especially since I am not using a real darkroom and the frame helped hold it all together. And I liked being able to dodge during the printing process, which I can't do with the diffuser in place, as you identified.

    I can't figure out how to get the old glass out of the frame. For now I have taped off a section of the frame that is scratch-free, but it forces me to use the lower left hand corner of the 8x10 sheet rather than the center, and I would not be able to use a larger (5x7) negatives.
     
  14. loman

    loman Subscriber

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    Thanks again for all your replies.
    I just got a little wiser... nice!
    Best Regards
    Mads