F stop scales!!!!!!!!!

Discussion in 'Large Format Cameras and Accessories' started by ruilourosa, Jul 17, 2012.

  1. ruilourosa

    ruilourosa Member

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    hello


    I am planning a compact and cheap lens kit like 210, 270, 305 all clarons... and i have a compur 1 where they all fit nicely, how could i do a f stop scale for the shutter (since i plan to use only that one and doing some screwing and unscrewing as i change the different cells), has anyone did this already? i know that convertible lenses have something like this, is it possible?

    thanks!

    Rui Lourosa
     
  2. ic-racer

    ic-racer Member

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    SK Grimes
    triple.jpg
     
  3. ruilourosa

    ruilourosa Member

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    ok it has been done!!!! i think i will try to make one myself, it seems a nice project...

    it would be nice to have scanned scales for different lenses, different focal lenght´s and different shutters, i think i will do it for the lenses and shutters i own!!! that way it would be easyer for new shuttering projects!!!
    working for the community!!! :smile:
    scans are welcome!!!

    Rui Lourosa
     
  4. Fotoguy20d

    Fotoguy20d Subscriber

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  5. TimmyMac

    TimmyMac Subscriber

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    Get a shutter with a scale for the 305. The 210 will be almost exactly one stop faster than the 305 at equal aperture needle settings. So f/11 on the 305 scale will be f/8 on the 210, f/16 will be f/11, etc.

    270 doesn't work as well, so... just don't bother carrying a 270 :smile:
     
  6. E. von Hoegh

    E. von Hoegh Member

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    Use the 210 component on the rear and the 305 component on the front, you'll get about a 255mm combination.
     
  7. Ian Grant

    Ian Grant Subscriber

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    Schneider once sold a Symmar convertible/combination set for a very short time, but you should in theory be able to use any Combination of Symmar cells in a shutter they fit. That should be possible with Plasmat type G-Clarons as well.

    Ian
     
  8. E. von Hoegh

    E. von Hoegh Member

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    The Dagor type G-Clarons can be mixed (not with the Plasmats, AFIK) and matched, as well. So can Goerz Dagors.
     
  9. ruilourosa

    ruilourosa Member

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    Interesting!!!

    crossing cells would affect quality? what about spacing... many questions!!!!!

    thanks

    Rui Lourosa
     
  10. E. von Hoegh

    E. von Hoegh Member

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    Correct spacing would be a job for an expert, which I am not.
    But, if you tweak the spacing until you get a flat field at say 50x the focal length, it will work surprisingly well. I did this with some old Dagor lenses from 6" to 300mm.
     
  11. ruilourosa

    ruilourosa Member

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    thanks fotoguy, i will post my measurements and my sales as soon as i do them!
     
  12. Jim Jones

    Jim Jones Subscriber

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    Instead of making the scales, calculate a correction chart for the other lenses and whatever scale is on the shutter.
     
  13. E. von Hoegh

    E. von Hoegh Member

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    Or, have a scale showing the iris opening in millimeters and use the chart.
     
  14. ruilourosa

    ruilourosa Member

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    i much prefer to have a direct reading of the f stop i´ll be using... it´s not hard to do the math but i teach and for the students it´s just a complication!