trying to focus on a small field

Discussion in 'The Darkroom' started by explody pup, Dec 24, 2006.

  1. explody pup

    explody pup TPF Noob!

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    Was goofing around and wanted to print some abstracts w/ overemphasized grain. I figured I could focus on a very small part on the negative (35mm) to get what I was aiming for. With the head fully extended along the rails, I still wasn't able to make the image large enough to get what I wanted.

    What can I do to magnify this small area? Is this what extension tubes are used for? What effect would a lens for MF printing have on a 35mm negative?

    Thanks.
     
  2. Flash Harry

    Flash Harry TPF Noob!

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    Use the enlarger to project the image on to the floor or a wall, your exposure time will be considerably longer but you should get the effect your looking for.
     
  3. Torus34

    Torus34 No longer a newbie, moving up!

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    To project an image on the floor unfasten the column from the base board, rotate 180 degrees about the vertical axis and remount it. Have a 10 pound weight handy to put on the base board so that the enlarger doesn't tip over. Then, you're set to go. You've increased the throw by the height of your enlarger table.

    If you've already made a print from the negative and recorded the original enlarger film-to-easel distance, determine the new film-to-easel distance and calculate the new exposure using the following factor [just multiply the original time by the factor]:

    Correction factor = (Final height)2/(Original height) 2
     
  4. explody pup

    explody pup TPF Noob!

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    Hey, cool. A lot simpler than I was thinking it was going to be. I've also been meaning to build a new baseboard since the original is warped (been leveling my easel w/ wedges when needed). Might incorporate a swivel or some kind of quick release to where the column attaches.
     

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