reversing the image

Discussion in 'Large Format Cameras and Accessories' started by johnielvis, Oct 13, 2013.

  1. johnielvis

    johnielvis Member

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    so shooting pan paper as direct reversal also reverses (mirror image) the image like positive weplates.

    There were olde photostat machines with reversing prisms, but they seem to not be able to be used with anything but shallow view angles--they would not work for wider angles of view.

    The only mirror boxes available seem to be of the tiny 2" variety for telescopes. There are large teleprompter setups that look like they may work if the beamsplitter is replaced with a regular 1st surface mirror.

    There are DIY instructions for mounting powerful binoculars with 1st surface mirrors to look at the stars.

    Is there anything else out there that anyone's aware of that would work. gettting a nice store-bought precise item is preferable to cobbling together some heavy oversized wood contraption. Or is there another word to search--"mirrorbox" only gets the telescope tiny ones and the diy binocular setups.
     
  2. bernard_L

    bernard_L Member

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    Do the initial shoot with the camera looking at the scene through a mirror reflection. Will be tricky/impossible with wide angle lens.
     
  3. ic-racer

    ic-racer Member

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    Some process lenses came with reversing mirrors. You could look for one of those.

    4077_KGrHqMOKm4E3cCnS1HbBNd2lqug_12_1.jpg
     

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    Last edited by a moderator: Oct 13, 2013
  4. johnielvis

    johnielvis Member

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    that first one looks like it's big enough--like 10 inches? Great--where to find one of them==so "reversing mirror" instead of "reversing prism". simple enough. anybody know where they have a big pile of them?
     
  5. johnielvis

    johnielvis Member

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    look for reversing mirror and you get video backup cameras for cars and trucks

    frustrating

    building one is not desired.

    the setups for videoprompters looks more like the only solution
     
  6. Bill Burk

    Bill Burk Subscriber

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    johnielvis,

    I think you may have to make your own from a front-surface mirror. Look for an old junk photocopier, some of the early ones used great mirrors. I had a mirror from one that was about 9x14 inches.

    But the reversing mirror assembly such as ic-racer showed you, is likely very rare. It's from an era when graphic arts was heavily film-based and where intermediates were carefully planned to be emulsion-to-emulsion for the necessary steps -- and the mirror assembly allowed one to break the rule. If you can find one, you will of course be set.
     
  7. johnielvis

    johnielvis Member

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    Yes--that's about the only conclusion to make--it's a DIY. New front surfact mirrors are pretty reasonable, it's just the mirror box--the construction of it--that's the problem. Maybe a job for Grimes, I guess. Alternatively maybe one of those 8x10 reflex viewers would work--those are probably more rare than the reversing mirror assemblies though.

    What is needed is someone who already built one (telescope hobbyists???) that wouldn't mind building another. Building precision objects without a shop is just not going to happen.

    Perhaps check the stargazer sites then?

    All other suggestions are welcome.
     
  8. ic-racer

    ic-racer Member

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    Something like this might work if you are using a long focus lens. You can buy these on ebay for $20.
    KGrHqNmEE-mhQ7PYBP7DI6G60_57-1.jpg
     
  9. johnielvis

    johnielvis Member

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    that's what gave me the idea...them are too small even for 35mm...no chance for the monster lenses used--even overhead projector reflex boxes/mirrors are too small.
     
  10. Bill Burk

    Bill Burk Subscriber

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    Can you build your camera on the chassis of an SX-70?
     
  11. johnielvis

    johnielvis Member

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    too small--this is for larger cameras with larger lenses--like 5" across--big--very big mirror needed. carpenter is needed. check out the DIY teleprompters out there--that's what is needed--only with a full reflecting mirror instead of the half silvered mirror. the mirror is easy to get--the precise box (and way to mount it to the lens) is not readily available. old projection televisions maybe? they should have the mirror mount and adjustment screws--they are a bit too big though.
     
  12. John Koehrer

    John Koehrer Subscriber

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    I don't think this would be a major project using plastic sheet and structural forms from ye olde hobby shop. Any shop that sells HO trains will stock it.
    The plastic sheet is sold in thicknesses from a few thousandths of an inch to over 1/16". Possibly thicker on the interweb.
    Cutting it with a utility knife is easy and plastic cement is common. Super glue would be too brittle. Needs care in cutting the angles and making it fit to a graflok back, no challenge.
     
  13. johnielvis

    johnielvis Member

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    Yes--but avoiding building is the goal here--when you don't build things that much you have to build things two or three times and it's ususally still lacking, you know?
     
  14. mjs

    mjs Member

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    Some 4x5 cameras have (or had,) reflex viewers offered which may solve your problem. I believe that Toyo was one of them, if I'm not mistaken. I used to know a fellow who used such a viewer on an Ebony 4x5 to give a right-side-up corrected left-to-right image but I haven't seen him in years and don't know where his viewer came from. I see them come up for sale occasionally on Ebay.

    Mike
     
  15. Dan Fromm

    Dan Fromm Member

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    Folks, this is the key part of the original post. What do viewers that clip on behind the ground glass have to do with it?
     
  16. richard ide

    richard ide Subscriber

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    They let you see what the image would have looked like if you had a mirror or erecting prism in front of the lens when you took the picture. :whistling:
     
  17. Steve Smith

    Steve Smith Subscriber

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  18. johnielvis

    johnielvis Member

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    GREAT LINK!--that was an idea--it may be the best idea actually--the most compact and most practical. special purpose camera for special purpose.
     
  19. Steve Smith

    Steve Smith Subscriber

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    This is a video of the camera with an integral mirror being used. In this case with Cibachrome exposed in camera and developed in camera too!

    [video=youtube;5AOlPuTQt-M]http://www.youtube.com/watch?feature=player_embedded&v=5AOlPuTQt-M[/video]


    Steve.
     
    Last edited by a moderator: Oct 20, 2013