Enlarged Positive from Neg

Discussion in 'B&W: Film, Paper, Chemistry' started by waynecrider, Oct 30, 2005.

  1. waynecrider

    waynecrider Member

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    Is it possible to get a "normal" contrast positive on film by enlarger exposure, without going thru the reversal process of the neg. The last I tried I used 8x10 Ortho film and the result was very low contrast. I just want good large positives.
     
  2. Donald Miller

    Donald Miller Member

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    Yes, it is possible to enlarge and produce an interpositive from a negative. I have used Aristo APHS for most of my efforts. Dektol 1-10 seems to get reasonable density ranges.

    You will need to come up with exposure times and a development regimen for your own equipment.
     
  3. smieglitz

    smieglitz Subscriber

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    Wayne,

    You don't mention the type of Ortho film you've used. I suggest you try Ilford Ortho Plus and develop it in either Ilford Universal for moderately high contrast or HC110 for moderate contrast.

    Were you using a litho film before? As Donald suggests, you could get acceptable results with that kind of film. The base fog would be much less than with the Ilford Ortho Plus, but the tonalities otherwise better with the latter film.

    Joe
     
  4. waynecrider

    waynecrider Member

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    I tried Bergger BPFB-18, the only large film I have.

    What about just using standard large film, something with a clear base?
     
  5. Aggie

    Aggie Member

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    What are you going to do with the positive? If it is to take it on to go further and make an enlarged negative from the positive, you will want the flat looking positive. To get more contrast, work with stronger developing solutions like you would for normal negatives. Also agitate more while developing.
     
  6. Donald Miller

    Donald Miller Member

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    The cost of conventional film is a lot more expensive then a film like APHS. The speed of conventional film is also faster then a film like APHS...this makes it more difficult to arrive at precise exposures.
     
  7. glennfromwy

    glennfromwy Member

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    I have some Fine Grain release Positive. I have always used it under a red safelight. Are you sure yours is not Orthochromatic? It does indeed make some pretty astounding B&W slides.
     
  8. waynecrider

    waynecrider Member

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    Aggie the end result I want is a larger positive.

    JDEF, from whe way I understand it, and as Aggie noted, it's the flat neg you want. As a projected neg the 5302 sounds interesting.
     
  9. Aggie

    Aggie Member

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    I do my interpositves and enlarged negs in steps. I've enlarged 35mm to 4x5 and then to 8x10. I don't see why you can't take a 120 neg and go up to a 8x10 if you wanted to get a larger positive. You needn't do contact interpositives. Just put the orginal neg in the enlarger and use the ortho film in an 8x10 film holder as your easel.
     
  10. SkipA

    SkipA Member

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    Not all ortho films are created equal. Kodak Kodalith ortho type 3 film is an extremely high contrast film. Great for silhouettes, but not much good if you are aiming for pictorial contrast.
     
  11. Aggie

    Aggie Member

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    I've used APHS ortho, Bergger ortho, ilford ortho, maco ortho, and lastly Kodak ortho. It is knowing how to deal with that type of film to get the contrast you want. I can get an extremely flat negative or a contrasty one with all of the above. It is all in the development and developer used. I also when I want a flat negative, will purposely fog the film. I also have watched and bought all the really old out of date kodak ortho film I could. I have some (500 sheets of 4x5) that is over 30 years old that is my favorite to use.
     
  12. SkipA

    SkipA Member

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    Aggie, what do you do to tame the contrast of Kodalith type 3, if I may ask?

    My technique has been to enlarge MF or 4x5 onto 8x10 Kodalith then develop to reversal via a dichromate bleach process. I then contact that onto normal sheet film (Bergger, usually), but I always end up with higher contrast than I want and a loss of middle grey tones.