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Thread: the Diana shutter

  1. #11

    the Diana shutter

    GG, I just looked at the holga and it is basically the same shutter design as the diana except that there's no "B" option on mine and the mechanism faces the film [the shutter faces the lens in a diana]
    the diana deluxe is a different, more compicated shutter to both the standard diana and the holga


    SlipRing, if I still had an 8 Banners shutter I would pull it apart for you...
    unfortunately I mounted it in a camera that was lent to my wife's nephew and I don't think I'll ever get it back

    if I remember right it was held together by rivet like fixings rather than screws so it wasn't ever meant to be pulled apart and if you do open one you may not get it back together again [which will explain why there isn't much on the net]
    however it would would be a VERY simple mechanism and making a thin shutter for wide angle is pretty easy if you only want long exposure times like for general pinhole use

  2. #12

    the Diana shutter

    SlipRing, I think this is how the 8 Banners shutter works
    you'll just have to excuse the cardboard cutouts and imagine simple spring loading of the two moving parts:

    closed position: Attached files

  3. #13

    the Diana shutter

    element on right rotates to start uncovering aperture

    Attached files

  4. #14

    the Diana shutter

    element on left rotates into notch to lock the right component in full open position
    when the left lever is pushed down it would allow the right element to close
    ie giving a "T" function as the default Attached files

  5. #15

    the Diana shutter

    if the left lever was pushed down the right element would rotate into closed position as soon as pressure was let off giving a "B" function


    the two components could be quite thin and would work better when sandwiched between two metal plates
    the pivot points would also be used to hold all the components together


    I think I might have these mirror imaged from the 8 Banners arangement but I'm pretty sure the principle is correct Attached files

  6. #16
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    the Diana shutter

    Nice! This thread slightly becomes what I always hoped to find somewhere: sharing ideas on flat, simple, minimalistic shutter mechanism which can be created (almost) on a kitchen table.

  7. #17

    the Diana shutter

    yep, the kitchen table is my main work space... it drives my wife nuts !!!

    I think my best shutter to date is here:
    http://f295.f295.org/uploads/Blah.pl?m-1197624328/s-0/
    I like that it's so darn thin, the brass is just sandwiched between 2 sheets of thin cardboard along with a small spacer strip each side to give just a little seperation so it moves smoothly

  8. #18

    the Diana shutter

    Andrew, I've built an almost identical brass sliding shutter as yours, in my little 2"x2" brass camera box.

    I've thought about mechanical shutters for refractive lens cameras for years; I have several rather complex designs in my sketch journals, some involving rotary shutters with variable width pie-shaped window slits to provide a variable shutter time; and other designs which are a variation on the guillotine shutter, but spring driven, with an adjustable width slit for varying the shutter time.

    I was just thinking about one of these last night as I was falling asleep. The problem with guillotine shutters is the acceleration from stop, one side of the image gets more exposure than the other (if the shutter is located near the film plane, that is) until the shutter begins to move at full speed. I recall a mechanism in high-end audio cassette decks of the 1970s/80s that permitted the cassette door to open slowly and smoothly. It was a little brass 4-vane rotary paddlewheel, whose shaft was gear driven to the spring-loaded door; as the spring pushes the door open the paddlewheel rapidly turns; the air friction of the paddle wheel rapidly turning slows and smooths the motion of the door, instead of it slamming open by spring force (like the cheaper cassette deck doors do.)

    I thought of this kind of mechanism, on a simpler scale, might permit a spring-loaded guillotine shutter to open smoother and evenly.

    I've also thought about these simple rotary shutters like what's illustrated here, which derive from the Brownie box camera era. The problem being is that you can't easily vary the exposure time with these designs.

    Still, to make a functional model I see two flat plates, seperated by standoff posts; the shutter mechanism is built in between the two plates, perhaps oversized to permit working and shaping the parts more accurately. The two plates have an oversized aperture hole front and rear, and is located in front of the lens or pinhole, on the outside of the box, for easy access.

    Great discussion. Now someone needs to get busy and build one of these.

    ~Joe

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