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  1. #1
    bvy
    bvy is offline

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    A Faster Leaf Shutter?

    I have several "lo-fi" cameras that employ a simple, single blade leaf shutter, the likes of which can be seen here.
    Click image for larger version. 

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    Wikipedia link

    What I'd like is to modify some of these to have a really fast shutter. I realize I'm not going to get 1/1000 or even 1/500 out of it, but something in the neighborhood of 1/125 to 1/250 would be wonderful. (My Vivitar Ultra Wide & Slim, for instance, clocks at a blurry 1/80 and usually overexposes). Given the limitations of its simple design, how fast can these shutters get (in theory or in practice)?

    And, in general, what are some strategies for speeding up such a shutter? The most obvious approach seems to be to add tension to the springs (the one that cocks the shutter and the one returns the blade to its closed position) so that the blade pops out of and back into position more quickly. I've done this with mixed results. Is there a better or more novel way?

    Thanks.

  2. #2

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    You're pretty much stuck with low speeds with that design. It isn't suitable for high speeds, this is the reason leaf shutters such as the Copal are designed as they are. Your shutter is the same design box Brownies were using over 100 years ago.

  3. #3
    Steve Smith's Avatar
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    If it had a wider moving leaf with a hole in it, it would give you an effective faster speed without actually moving faster. Instead of uncovering the lens it would just pass an aperture over it.


    Steve.

  4. #4

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    Quote Originally Posted by Steve Smith View Post
    If it had a wider moving leaf with a hole in it, it would give you an effective faster speed without actually moving faster. Instead of uncovering the lens it would just pass an aperture over it.


    Steve.
    A sector shutter. It seems his shutter moves the leaf away, then back. He'd have to modify it with a new blade, and then solve the problem of cocking it.

  5. #5
    Ken Nadvornick's Avatar
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    Quote Originally Posted by Steve Smith View Post
    If it had a wider moving leaf with a hole in it, it would give you an effective faster speed without actually moving faster. Instead of uncovering the lens it would just pass an aperture over it.
    In effect, this is what happens with the little rotary shutter in a Kodak Hawkeye Brownie. A cutout hole in a larger leaf, where larger in this case means a rotating partial disk. I simply used black photo tape to mask the cutout to a smaller size. Trial and error with a shutter speed tester guided the degree of masking required to achieve the speed I wanted.

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    —Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  6. #6
    ic-racer's Avatar
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    Quote Originally Posted by bvy View Post
    I have several "lo-fi" cameras.......clocks at a blurry 1/80
    Am I missing something? Isn't that the point of a "lo-fi" camera?

    Did you try cleaning the shutter? Maybe it was faster when new.

  7. #7

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    Flash several stops above ambient will create fast 'effective' shutter speeds. Pry it with a Buff Einstein mono light.

  8. #8
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    I came here to suggest what Steve did. You can replace the blade with a wider one; it will possibly move slower if you make it heavier but you can reduce the total exposure by cutting a narrow slot in it that passes over the hole. If you can't prevent the shutter blade from returning you will get a kind of double exposure though; one swipe of the slot each way. If nothing else, the results would look very funky with fast-moving subjects like propellers!

  9. #9

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    Um, Polyglot, would you by any chance have a bakelite-bodied Brownie Hawkeye? I ask because that was my first camera and until I learned how the shutter worked I got unexpected and sometimes surprising double exposures with it.

    This because pushing the shutter release lever down fired the shutter and pulling it up also fired the shutter. I think the wikipidia entry bvy directed to us misrepresents how those shutters function.

    More seriously, the simple shutters being discussed are a kind of guillotine shutter. Sector shutters have been used in a few still cameras (Univex Mercury, Olympus Pen F) but are nearly the norm for cine cameras. The Agiflite, an aerial camera that shot 6x6 on 70 mm film and is essentially a cine camera with a low framing rate, has a rotary sector shutter whose top speed is 1/2000.

  10. #10
    polyglot's Avatar
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    I don't have any sector- or guillotine-shutter cameras, though I've considered building one so that I can use an Aero Ektar.

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