Two 617 negs / on a 5x7 Camera. Built June ’93

Discussion in 'Large Format Cameras and Accessories' started by Reinhold, Nov 30, 2017.

  1. Reinhold

    Reinhold Advertiser

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    My first foray into the 6x17 film format was back in 1993.
    After I trimmed a few 5x7 negatives to 2-1/2 x 7”, I started to get the fever…
    I tinkered around with cutting a dark slide for splitting an exposure to 1/2 of the film,.
    Light spilling across the dark slides split edge killed that idea.
    Also, logistics out in the field keeping track of which half was exposed was daunting..

    Hmm…I’d need a septum in the camera to split the image to 2-1/2 x 7”
    Then a light bulb lit up in my brain…
    Why not flip the film holder?
    Better yet, why not flip the ?

    The ideas in my brain steered my pencil, and a concept sketch was born…
    A used 5x7 spring back, some brass clips to permit 180° rotation, a few days in my shop, and the Alpha Model of a minimalist camera to place two 617 negatives on one 5x7 film became reality.

    617 camera_1102 2.JPG 617 Cam._1103.JPG 617 Cam._1105.JPG 617 Cam._1106.JPG BR 446. 2x 5x7 neg copy.jpg 617 sketch.jpg

    Warts and all, that simple, crude, Alpha Model has been in service for the past 25 years.

    Some specifications:
    Lens (no tilt): 90mm f:4.5 Nikkor SW
    Lens (image) axis is prox 1/3 high on the image area
    (Thus the lens is placed to favor the foreground).
    Bellows total extension: 50mm (focus slot length)
    Back Swing: ± 5°
    Back Tilt: -5°, +12.5°

    Reinhold

    www.re-inventedPhotoEquip.com
    www.ClassicBWphoto.com
     

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    Last edited: Nov 30, 2017
  2. Fluidphoto

    Fluidphoto Member

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    Brilliant idea.
     
  3. EdSawyer

    EdSawyer Member

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    nicely executed!
     
  4. Craig

    Craig Subscriber

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    How close is the septum to the film? Does it touch the darkslide when you have the film holder in place?
    That's a very well executed solution to the problem of putting 2 exposures on a sheet.
     
  5. mshchem

    mshchem Member

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    FUN!
     
  6. OP
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    Reinhold

    Reinhold Advertiser

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    The plane of the septum is 1/2mm (±0.020") below the plane of the ground glass.
    Obviously, when I insert a film holder, everything is displaced backwards, so there's never a conflict.
    As you can see in the negative, the shadow edges of the septum are (relatively) sharp.

    Reinhold
     
  7. Craig

    Craig Subscriber

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    Thanks. I'm certainly impressed!
    It's a very timely thread, I just borrowed a 90mm lens this week from a friend to try out this concept on my 8x10 and was trying to think of way to not waste most of a sheet of film.
     
  8. Ryeman

    Ryeman Member

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    Reinhold, this is very impressive. I have several questions but will limit myself to one. If you simply blocked out the upper half of the back of a conventional 5x7 camera then the centre of the lens would line up horizontally with the top edge of the 6 x 17 image area. In your camera you have either lowered the lens, or raised up the darkslide, or both, in order to get the centre of the lens to line up horizontally with the horizontal centre of the image. This must make a difference or you wouldn't have done it. Is it because you wanted to utilise the central band of the lens instead of its "top half" ? Or was it because the lens coverage didn't quite reach the corners? Yes, I know, that's two questions!

    Alan
     
  9. Ian Grant

    Ian Grant Subscriber

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    I wish you'd posted this years ago, I bought a 6x17 camera about 2007 :D Great practical idea.

    Alan, as Reinhold biult the camera from scratch he could optimise the lens position for the bottom half of a sheet of 7x5 film, and you would want to use the central band of the lens image circle. These 90mm lenses cover 7x5 but not with much room for movements.

    I keep putting off my plans to do something similar, I have a spare parts Seneca City View 7x5 camera, the front of the focus bed has front shift and can also be split making it ideal for a WA 7x5 or6x17 camera, the rising front part that takes the lens board is missing but I've made a new one to take my Wista/Linhof lens boards. If I'm careful I could offset the lens position to do the same as Reinhold and shoot two 6x17 negatives on each 7x5 sheet, and make a removable baffle bit to allow full frame as well. That would alleviate the need to make a dedicated 6x17 roll film back and be cheap and simple.

    Ian
     
  10. Ryeman

    Ryeman Member

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    Thanks Ian. I too had thought about incorporating a removeable baffle in a conventional 5 x 7 camera, to get full frame and 6 x 17 - the best of both worlds. If the camera had falling front the lens could be dropped down to optimise it for 6 x 17. Can you manage that with yours? No problem for me as I would be building the camera from scratch.
    I'm very tempted to build one. Brilliant idea Reinhold.

    Alan
     
  11. Ian Grant

    Ian Grant Subscriber

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    Alan, there's enough rise/fall with my Seneca City View to allow me to optimise it for 6x17 and regular use. It's a project for warmer weather now though.

    Ian
     
  12. Vaughn

    Vaughn Subscriber

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    I have had no problems with a modified darkslide (I do not go as wide as you do), but this is a very nice build. Does it adapt for verticals, also?

    If I remember to do it, I center the lens on the part of the film to be exposed. My Fuji W 250/6.7 will easily handle 5.5x14, but has trouble hitting the corners of 11x14.
     
  13. Ian Grant

    Ian Grant Subscriber

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    It won't adapt for vertical Vaughn because a the lens is offset towards the centre of the bottom section in the film holder and so there wouldn't be lens coverage with that 90mm.

    I'd be interested in doing something similar with one of my Agfa Ansco 10x8 cameras. I've already made a conversion lens board to use Wista/Linhof lens boards but as they are quite large I could make another board to offset the Wista/Linhof type lens board downwards dropping it a a couple of inches maybe a touch more.

    Ian
     
  14. Ryeman

    Ryeman Member

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    To take vertical pictures I suppose you could turn the camera on its side. I notice Reinhold's camera has rear swing, which would become rear tilt when turned through 90 degrees. Handy for getting front to back focus with a vertical image.

    Alan
     
  15. SMBooth

    SMBooth Subscriber

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    Nothing seems to solve the problem that I don't have a 5x7 enlarger....
     
  16. Ian Grant

    Ian Grant Subscriber

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    I feel the same about using my 12"x10" camera as I don;t have an enlarger large enough. You can contact print but hey I thought that when I bought a 10x8 camera until I held a negative and instantly wanted to enlarge it :D

    A few years ago when pro labs were closing left, right, and centre, it was easy to pick up 5x4, 7x5 and 10x8 enlargers, sometimes larger, very cheaply, many went to landfill unsold

    Ian
     
  17. Vaughn

    Vaughn Subscriber

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    Some of us contact print and appreciate the film rebate being all around the image area.
     
  18. OP
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    Reinhold

    Reinhold Advertiser

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    Instead of making the camera for two 617 negatives, you can make it for two 615 negatives which can be enlarged in lots of 4x5 enlargers.
    The Beseler M series, for example, has a 6-7/8" diameter negative base plate which easily takes a 615 negative.

    Here are a couple of posts I did a while back on the advantages of 6x15 format, which just happens to be the same ratio as 8x10" ULF film.

    https://www.photrio.com/forum/threads/6x15-an-old-oddball-format-for-120-film.143873/
    http://classicbwphoto.com/classicBWphoto/Fotoman.html
    http://www.film-and-darkroom-user.org.uk/forum/album.php?albumid=580

    Here's a scan comparing 612, 615, & 617 film sizes...

    Reinhold

    612.615.617 scan.jpg
     
    Last edited: Dec 2, 2017
  19. Vaughn

    Vaughn Subscriber

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    I am going to be using an 6cmx10cm...another country heard from...