Dell 1080p Lens for Speed Graphic?

Discussion in 'Camera Building, Repairs & Modification' started by hazardsg, Feb 12, 2013.

  1. hazardsg

    hazardsg Member

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    Today at work I rescued the lens from a Dell projector that was about to go in the garbage. I was wondering if it would be possible to mount it to a lens board to use with my speed graphic. I've heard of using different types of lenes with the Speed Graphic's focal plane shutter, but Ive never heard of a lens out of a modern projector being used. Here are pictures of what the lens looks like.



    2013-02-12_15-46-17_799.jpg 2013-02-12_15-46-24_189.jpg 2013-02-12_15-46-27_934.jpg

    The front element is what I think I would have the best luck using.

    2013-02-12_15-46-52_230.jpg 2013-02-12_15-46-57_57.jpg

    With as small as the rear element is, I don't think it would work. Is that a fair guess? If I do mount it to a lens board, how do I figure the aperture? Is there a better method than guessing and checking? Thanks for any information.

    Steven
     

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  2. hazardsg

    hazardsg Member

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    Not sure why the development tank pic is attached. Oh well...
     
  3. Whiteymorange

    Whiteymorange Member

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    Hold the lens toward a light source (window, ceiling light, whatever) and put a piece of white paper behind it. Move the paper until you see an image. If the lens resolves an image, you can take pictures with it. Try the same with a magnifying glass if you're having difficulties and try to get the hang of it. My guess is that the focal length of this lens might be too short for something like a speed, but you never know until you try. Working out the speed of the lens is simply a matter on measuring the diameter of the rear opening of the lens housing and dividing that number by the focal length at infinity. This is a rough estimate at best given the way you will work out the focal length, but it can be a starting place for figuring exposure times. I have found most lenses from slide projectors and movie projectors to be quite fast, in the f1.9 to f4 range, but I have also found that they average 15-35 mm focal length, with some bigger, older ones coming in at 100mm. Again, you won't know until you play with it. Have fun!
     
  4. polyglot

    polyglot Member

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    Sure you can but the coverage will likely be tiny. It's designed to project the image of a tiny (inch or two) LCD, which means that you're likely to only get a couple inches of illumination in the middle of your film.

    And the focal length is probably very short, so to get it to focus, you need to have it very very close to the film and the lens board won't be simple.

    Try focusing an image on paper with it - that will tell you what size image and lens/film separation it needs.
     
  5. rthomas

    rthomas Subscriber

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    I'm not too familiar with the Speed Graphic, but I assume there is a way you can open the shutter and focus on the ground glass. If that's the case, just mount that lens on a piece of mat board big enough to cover the lens board opening on the Graphic. Then, open the shutter and hold the lens in place, and see if you can focus at all, and what the image looks like on the ground glass.
     
  6. EASmithV

    EASmithV Member

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    it might make a good macro lens.