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  1. #11
    David H. Bebbington's Avatar
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    Quote Originally Posted by Surly
    I just want to build the shutter myself and I dont want it pneumatic.
    Any other suggestions for the overall deign are certainly welcome.
    Off the top of my head, if you wanted to build a shutter which is "all your own work", the simplest kind to make would be a guillotine shutter, which is basically a piece of thin wood about 5 or 6 times as long as it is wide with a hole in the middle. This runs vertically between two wood rails, to fire it, you first raise it so the hole is higher than the lens and hold it in place with a releasable detent. To release it, you then disengage the detent, the shutter drops, either by gravity or driven by a rubber band, etc. the hole in the wood passes the lens and comes to halt beneath this. If you can find a Victorian photography book from the 1850s or 1860s, you might even find some working drawings, since there were no commercially-available shutters at this time and people made their own.

  2. #12
    Surly's Avatar
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    Ahh, now were gettin somewhere. Gravity shutters,great idea, I'll throw that in the sketchbook.
    Donald-you seem to be smellin what I'm steppin in. Rotary with a spring or two with one speed and B. Thin brass circle with a hole in it etc.... This is what I originally had in mind and I was looking for maybe a picture of what someone else has done. I found pictures of a Holga shutter, I have a Kodak with a shutter like I'm talking about but I cant get the thing apart without damaging it and it works so I'm going to leave it alone.
    Great ideas-keep em comin.

  3. #13
    Murray@uptowngallery's Avatar
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    Ho-ho, strange ideas you want, eh?

    The gravity/guillotine concept has a name I can't remember...maybe Andrew Davidhazy at RIT has it posted on his site. I have heard of it used with 3 separate color filters (hey, like Neopolitan ice cream!), that sequence past the lens...I just can't remember the surname who it's asociated with.

    I usually see those craft sticks (for those too lazy or allergic to clean the ice cream off first) used for little houses. I have some that are half the width and have holes at the ends because they were intended to be laced together for some project. That must have some photographic application.

    I just, uh, copied the chapter on shutters from the Kingslake-edited Applied Optics and Optical Engineering 5-volume set - found it in the library at work. They refer to another linear shutter called a 'shooting plane' shutter...I had thought this up myself but dismissed it as too bizarre...turns out it exists. Apparently it's like when I was a kid and I got my sister's boyfriend to put his Ducati motorcycle up on it's kickstand that lifted the rear wheel off the ground. We'd put 2x4 lumber between the tire and the ground, he'd rev up the engine and lean back until the time hit the wood, shooting boards down the driveway.

    With a shooting plane shutter, metal plate, similar to a FP curtain shutter, with one or multiple slots, is engaged by two or more idler wheels that accelerate it to speeds up to 500 inches per second. There are 'brushes' to catch the plate at the other side.

    Now, I ran into a guy at my last job, a contract engineer, who worked at Chicago Aerial Industries (now ReCon Optical I think). I asked him whether the large mass of the camera was one factor in what allowed hyper springs on big shutters to not blur images. He gave me an interesting concept - at least for leaf shutters, they can bang & clatter all they want at the beginning and end of the motion, because the shutter is closed at those points. You want smooth motion during the open (efficient) phase of the shutter motion.

    Small idea - see what's inside a typical disposable camera. Labs are really skittish and inconsistent about who will give you the empties or not. One clown wanted my name phone # & address...I accused him of dragging me into a marketing ploy but he thought it was more like Homeland Security. Last time I went there! Ugh, it never occurred to me there was a third possiblility, but I don't want to think about that.

    Big idea - I bought a box of 'Lazy Susan' bearings (plates with bearings) to experiment with a 6-7/16" hole. It's large enough to pass an Aero-Ektar 309/2.5 lens barrel. The idea was to make a 4-leaf or butterfly-bladed shutter with hand rotation. The butterfly type takes more room but doesn't have to reverse direction, just accelerate, open, decelerate. I'm still examining other reversing blade shutters to figure the shape and dimensions to fit the curvature of the Lazy Susan aperture. I'm also doing the geometry for a multi-aperture plate (like on old lenses) that can be rotated into position. Two of these back to back might allow a large Lazy Susan and Lazy Iris to be accomplished in a thin space. I have a 12" Metrogon lens set that is rumored to need less than 1/4" space between....that's part I'm still researching.

    Once I get one working, I can probably use the smaller L.S. bearings in the future. I talked to a place that makes photoetched parts to make blades, but don't want to spend that $ right now...I'm looking at spray-painting the clear fronts from CD cases, thin, rigid, lightweight...

    Murray
    Murray

  4. #14
    Murray@uptowngallery's Avatar
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    Well, this stinks! It doesn't matter that I can fit 9 stops on the big Lazy Susan bearing if the physical aperture at the back of the lens is large (66 mm in an 80.2 mm plate on 12" Metrogon). The 9 stops overlap the lens so more than one is illuminated...dim idea...

    I might only be able to fit 3-4 stops in a circle spaced far enough apart to not be exposed more than 1 at a time. A linear array of Waterhouse-style stops would be as long as a monorail! Hmmmm.
    Murray

  5. #15

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    Quote Originally Posted by Murray@uptowngallery
    Well, this stinks! It doesn't matter that I can fit 9 stops on the big Lazy Susan bearing if the physical aperture at the back of the lens is large (66 mm in an 80.2 mm plate on 12" Metrogon). The 9 stops overlap the lens so more than one is illuminated...dim idea...

    I might only be able to fit 3-4 stops in a circle spaced far enough apart to not be exposed more than 1 at a time. A linear array of Waterhouse-style stops would be as long as a monorail! Hmmmm.
    Murray,

    sounds like you might need 2 or 3 circular plates with diff apertures on them (one of them being wide open on each plate). Put 2 plates on wide open, the third one selects a smaller f-stop (or wide open, even). This way you can fit 10 stops total (3 different on each plate, and wide open).

    just a thought,

    André

  6. #16

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    Um, er, ah, the words that members of the Lazy Susan set are groping for are "rotary sector shutter with variable sector angle." Widely used in cine cameras.

  7. #17
    Donald Qualls's Avatar
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    Quote Originally Posted by Surly
    Donald-you seem to be smellin what I'm steppin in. Rotary with a spring or two with one speed and B. Thin brass circle with a hole in it etc.... This is what I originally had in mind and I was looking for maybe a picture of what someone else has done. I found pictures of a Holga shutter, I have a Kodak with a shutter like I'm talking about but I cant get the thing apart without damaging it and it works so I'm going to leave it alone.
    Great ideas-keep em comin.
    Surly, take a look here and you'll see some excellent pictures of a large rotary shutter (in a 116 format box camera) and how to convert it to B-only operation. It should be pretty obvious how to make the B setting optional, and there's enough detail in those photos that you ought to be able to fabricate one with no other references.

    If that doesn't do it for you, find any Ansco box camera and slip the front off by lifting the tabs on the two long sides off the short pins -- the whole shutter is right there, out in the open. If you get a 116, you might be able to simply take the whole shutter board and install it on your 4x5 box (saving a fair amount of labor). Alternately, e-mail me and I'll take some detailed pictures of the shutter in my Shur-Shot Jr.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  8. #18
    Murray@uptowngallery's Avatar
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    Magnet over red widow for high-ISO film...that's a good idea...I was just wondering if a recent acquisition had permanently open red windows & what to use other than black tape. I will check the cam-back for ferro-magnetic properties.

    Murray
    Murray

  9. #19
    Donald Qualls's Avatar
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    I've never found it necessary to cover red windows for ISO 400, either color or B&W, whether with Kodak films or Lucky SHD 400, or even the very inexpensive J&C Pro 100 -- even in a camera with the red plastic gone from the windows. I've seen examples of fog-through with Efke 100, however, and I can't speak for Delta 3200 (though TMY pushed to 3200 showed no problem, it wasn't exposed to sunlight while in the camera). The only problem I've ever had that I could reasonably ascribe to the red window was edge fogging from reflections, which will happen while advancing (when the red window has to be open) just as readily as when the camera is sitting.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  10. #20

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    You might look for a GITZO lens front shutter. It has Instant (probably 1/25th), B and T only, operates via a cable release and fits lenses up to 80-something mm in diameter.

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