Enlarged B&W Negatives, no problem.

Discussion in 'Enlarging' started by inthedark, Jul 9, 2003.

  1. inthedark

    inthedark Member

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    Enlarged B&W Negatives

    Okay I have just been reading "Enlarged negatives using ...." from www.unblinkingeye.com as I have noticed a few discussions about a need for this. After reading and re-reading, I have to say I already do this but for a different purpose, and I have been using enlarged paper positives rather than contact internegatives. It is an old printing trick which I use for aerial mosaics. Now airplanes do not stay perfect in relationship to the ground so when mosaicing I have to impose corrections on to the images as they are being spliced together. so what we do is used enlarged enlargements, bigger than the enlarged negative by 300% to 600%. We check accuracy,and at this size even tonal adjustments can be made with the appropriate emulsion stains.

    Since my mosaicing requires a sewing technique as well, called darts, my next step is to let this dry of corrections, clean it with film cleaner to remove any residuals, and apply it to a vacuum or pressure press for 24 hours to re-flatten it. But I could easily see the advantage of using film if re-construction isn't necessary. Also my cameras are made for flatwork (pre-press or newspaper negatives if you will) and are trammed to .001mm corner to corner, with pressured copy board and vacuum negative carrier which can take negatives up to 24"X36". I have a full size selection of ortho halftone films and the screens too, BUT why stop there, I can get fully continuous tone film with grain even to about a 200asa film up to 42 inches wide I believe, but you won't need it that wide. And wow, I have been able to successfully enlarge one of these negatives up to 600% flawlessly, and up to 1000% reasonably (usually I only enlarge negatives to 10 x 10 as my enlarger doesn't need me to consider contact size.)

    The only concern I have is that I don't have access to enlargers and printers like you all have. And my light deck is completely foreign to anything I have read about here. So it may take me a while to determine the correct amount of fog or mask layer to be suitable for you. I believe one of our fellow posters is sending me a test negative, but I think this will be pretty straight forward. Start telling me now, though, what I should be looking for and at when I am doing this. Remember I am not a photographer and the engineering types I deal with probably have different requirements than you. So I will need lessons in "seeing" and I hope I can get the vision to see what is important to you all.

    I have also been playing recently with doing this with color. Necessity I am afraid as this years mosaic will be in color. So before long I should have a possibility of this concept in color; six months maybe depending on busy I am with "real" work.
     
  2. inthedark

    inthedark Member

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    OOps! Should read, "...paper positives rather than interpositives."
     
  3. Aggie

    Aggie Member

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    to do a base fog on film i enlarge, i use a basic ordinary sytrofoam cup. I test to see how much it will fog when i hold it over the lense and the enlarger turned on. I do one second tests like a test strip when printing. I go for just a hint of fog. If someone has thrown out my high tech piece of equipment, i resort to letting our not so safe safe lights add a bit of fog. with them it takes a count of 11 to do what I want on a particular enlarger. Then wonders of wonders i juxst sue the same chemistyr for the people working with paper developing to do my postives, then the larger negatives. You can check out my van dyke and cyanotype in the technical gallery to see how successful I have been.
     
  4. Ed Sukach

    Ed Sukach Member

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    Arrrghh!! What happened to your avatar? The old one was so ... GOOD!!!
     
  5. inthedark

    inthedark Member

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    Since I wasn't the photographer and I have been reading the ethics, etc. threads, I thought I should check with him. But he is our of town for the month. Sorry, reality bites,huh! LOL :wink:
     
  6. inthedark

    inthedark Member

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    Hey, Aggie, long time. What a great idea. My camera comes equiped with a "flash" light, but I am already thinking about how I could use that concept with some of the extreme contact prints I have tried. I wonder if cups like that come in colors, it might be useful for color flashing. I've tried a few things, but so far I am not satisfied with my color fogging when necessary.

    I will find the technical gallery and check out the abovementioned. What is a van dyke and cyanotype. Geez, I got lots to learn.
     
  7. inthedark

    inthedark Member

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    Okay, Aggie, been to the tech gallery and I guess it is pretty self explanatory. Cyan and Van Dyke Brown,...anyway, yes I would agree that you have it figured out. I really like the vandyke church, very nice.