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Thread: 3.25 x 4.25 Graflex

  1. #41
    Bill Kostelec
    Join Date
    Oct 2013
    Location
    Spokane, Washington
    Posts
    150

    Re: 3.25 x 4.25 Graflex

    Quote Originally Posted by Bill_1856 View Post
    I take it that you don't actually own a Graflex.
    The Graflex focal plane shutter cloth is on a roller (like a window shade) with several slits cut into it. They are of different sizes. How fast they move across the film plane is determined by the tension in the main spring which causes the roller to unroll. At a high tension the roller moves fast. How long the film is exposed to light then obviously depends on the width of the slit. A little bitty slit moving across the film plane driven by a high spring tension gives relatively short exposure time. A wide slit moving slowly gives a longer exposure. What combination is determined by how tight the spring is wound, and how far the roller is wound (think of a window shade pulled to the bottom of the window, or raised to the top.) The actual exposure times are determined by the different models of the camera. The shutter is "closed" by the amount of solid cloth between the slits.
    It's a beautiful, simple arrangement, and was used on the original Leicas before the truly self-capping shutter of the production model A, but it required that the lenscap must be in place to prevent fogging the film when the shutter was rewound. This is also necessary on the Speed Graphic (or a dark-slide is inserted into the film holder) -- the Graflex beautifully eliminates the problem by closing off the light path by the mirror (you can't rewind the shutter until the mirror has been dropped).
    Bill: I don't understand your comment that your graflex is not self capping? What you described is exactly correct, so how is that not self-capping? I own a RB4X5 Graflex and have taken out the shutter, repaired it and reassembled, with three years of steady service since. Your comment in #38 says that your Graflex shutter is NOT... That's what is confusing. My comment was referring to the ease of using the Bag Mag on the Graflex, so that I don't have to replace the darkslide as the shutter is capped and the mirror must be down to rewind for the next shot. With the mirror down and the shutter cloth as an opaque screen the film in the bag mag is perfectly screened from light.

    the other Bill

  2. #42

    Join Date
    Jan 2001
    Posts
    4,585

    Re: 3.25 x 4.25 Graflex

    Quote Originally Posted by blueribbontea View Post
    Bill: I don't understand your comment that your graflex is not self capping? What you described is exactly correct, so how is that not self-capping? I own a RB4X5 Graflex and have taken out the shutter, repaired it and reassembled, with three years of steady service since. Your comment in #38 says that your Graflex shutter is NOT... That's what is confusing. My comment was referring to the ease of using the Bag Mag on the Graflex, so that I don't have to replace the darkslide as the shutter is capped and the mirror must be down to rewind for the next shot. With the mirror down and the shutter cloth as an opaque screen the film in the bag mag is perfectly screened from light.

    the other Bill
    Self-capping is, by definition, like the Leica/Contax/etc shutters, which close the slot except when the exposure is being made, so they can be rewound without exposing the film.
    A Graflex requires that the mirror be flipped down to the viewing position in order to rewind the shutter -- thus it requires a separate action, and is not SELF-capping. For example, if the mirror has been tripped independently before releasing the shutter in order to avoid vibrations, if you forget to put it back down after taking the shot, then the roller can't be rewound without exposing the film. There are restrictions built into the camera to avoid this, but it CAN be done.
    I won't belabor the point further -- it's still a wonderful camera.
    Wilhelm (Sarasota)

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