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Thread: adding a 7x11 expansion back to an 8x10

  1. #1

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    adding a 7x11 expansion back to an 8x10

    In my 8x10 kit I carry a 4x5 reducing back and wooden splitters that fit inside the 8x10 spring backs on my Kodak 2D and Century Universal that permit 4x10 and 5x8 formats. I love the versatility this gives me--four formats with one camera. Recently, I decided to try to add a fifth format--7x11. I purchased a vintage 7x11 back from Jim Galli that I thought would be a good, vintage match for my older cameras. I knew the 7x11 back would need to be modified. I wasn't sure how much of an extension I would need to avoid vignetting, but I thought it was doable. Thinking that somebody else might be interested in trying this, I am posting to share my experiences in adding a 7x11 back.

    When the back arrived from Jim, I was delighted to measure the depth and discover it was over an inch thick. It was also 11 and 7/8 inches square (o/s), and my camera backs are 11 and 1/2. I took the back to a woodworker who has helped me with vintage camera mods in the past and had him trim the top and bottom to 11 and 1/2 (I decided to forgo portrait mode for the time being). I went back a second time and had him trim out the inside to a true 7" x 11" since the original opening was quite a bit smaller (about 1/4" each way).

    To make the back usable without adding a cumbersome 2-3" thick spacer, I filled in the rabbet and added a new light trap myself. Pictures below.

    W/o any additional spacer, the back is usable with 2-3 lenses: a 159 ExWA Wolly, a 210mm Fuji (these two do not vignette even when wide open), and I think I can use it with a 300mm when stopped down (need to verify this last).

    First pic below shows the back w/o gg after trimming. Second shows detail of the top/bottom cut. Third shows detail of the inside opening.
    Attached Thumbnails Attached Thumbnails 2010_0523Image0017.JPG   2010_0523Image0018.JPG   2010_0523Image0019.JPG  

  2. #2

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    Re: adding a 7x11 expansion back to an 8x10

    1/8 x 1/8 basswood trim to fill in the rabbet...
    Attached Thumbnails Attached Thumbnails 2010_0523Image0020.JPG   2010_0523Image0021.JPG   2010_0523Image0026.JPG  

  3. #3

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    Re: adding a 7x11 expansion back to an 8x10

    with the 7x11 back on the camera, w/o gg, you can see the potential for vignetting with the bellows frame.... Second pic shows an angled view to the side/corner...
    Attached Thumbnails Attached Thumbnails 2010_0523Image0027.JPG   2010_0523Image0028.JPG  

  4. #4

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    Re: adding a 7x11 expansion back to an 8x10

    these show how the new back lines up with the existing corner brackets. I thought it would be dicey drilling holes for the new pin placement, but it turned out not to be a problem....
    Attached Thumbnails Attached Thumbnails 2010_0523Image0029.JPG   2010_0523Image0030.JPG  

  5. #5

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    Re: adding a 7x11 expansion back to an 8x10

    these show the new light trap added to the back. 3/16 basswood.
    Attached Thumbnails Attached Thumbnails 2010_0523Image0031.JPG   2010_0523Image0033.JPG   2010_0523Image0037.JPG  

  6. #6

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    Re: adding a 7x11 expansion back to an 8x10

    new 7x11 back on 8x10 camera
    Attached Thumbnails Attached Thumbnails 2010_0523Image0039.JPG   2010_0523Image0042.JPG   2010_0523Image0044.JPG  

  7. #7

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    Re: adding a 7x11 expansion back to an 8x10

    I'm working on a 2" thick spacer to use for longer lenses. I'll post pics of it in a day or so. The 2" spacer will also make it easy to reverse the back for portrait orientation.

    If you are interested in this, eddie currently has a 7x11 back for sale (and about 20% less than I paid for mine, so it's a good deal).

  8. #8
    funkadelic
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    Re: adding a 7x11 expansion back to an 8x10

    Were the backs modified to accept the splitters, or were the notches (like a Deardorff?) already there? Also, are the backs interchangeable? I'm waiting for a Century Universal to arrive any day now...
    It would be nice to see 7x11 capabilities on it one day.

  9. #9

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    Re: adding a 7x11 expansion back to an 8x10

    My 2D and CU backs were originally made to accept wooden splitters. The have brass inserts, apparently with some sort of spring inside the slots as well. The splitters have a longer and a shorter edge--push in the longer edge, then fit in the shorter one and wiggle a bit to adjust into place. Yes, my two backs are interchangeable. The CU and 2D were in production at the same time, so apparently the Folmer Graflex Division/Folmer-Schwing folks took interchangeability into account--or they just used the same parts and designs for both backs.

    My 2D is a late model--'48, I think. The CU is around 1935. I don't know if FG/F-S or Deardorff came up with the grooved back splitter design first. Maybe somebody else knows....

  10. #10
    funkadelic
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    Re: adding a 7x11 expansion back to an 8x10

    I'm not sure who came up with it first, but it sounds like the grooved back is similar to the Deardorff back splitters. I've owned a couple of Deardorffs, and several backs. Not all of the 8x10 'dorf backs have the groove/notch.

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