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Thread: Chamonix H-1 and Imagon 250mm

  1. #11

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    Re: Chamonix H-1 and Imagon 250mm

    Point being, calculations are not as useful as one might believe due to the unpredictability of how images and their required image ratios vary all over the place due directly to the nature of view camera lenses which do NOT have a fixed back focal length as with fixed lens box based cameras.

    At some point it is quite possible a lens with longer than 250mm / 10" focal length could be needed. Once above 300mm, the bellows/camera extension of 370~ mm will prove to be no where near enough.

    These are the very real world limitations of a light weight field folder cameras that modular monorail cameras simply do not have. Camera choice is completely dependent on lenses needed to achieve the image goals and what hardware is required to achieve the expected image goals.


    Bernice



    Quote Originally Posted by olk View Post
    Is this a guess or did you calculate that more than 340mm bellows extension is required for the Imagon (focal length nominal 250mm but as Drew mentioned it is actually 276mm) for head/shoulder portraits?

    Oliver

  2. #12

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    Re: Chamonix H-1 and Imagon 250mm

    Quote Originally Posted by Bernice Loui View Post
    Point being, calculations are not as useful as one might believe due to the unpredictability of how images and their required image ratios vary all over the place due directly to the nature of view camera lenses which do NOT have a fixed back focal length as with fixed lens box based cameras.

    At some point it is quite possible a lens with longer than 250mm / 10" focal length could be needed. Once above 300mm, the bellows/camera extension of 370~ mm will prove to be no where near enough.

    These are the very real world limitations of a light weight field folder cameras that modular monorail cameras simply do not have. Camera choice is completely dependent on lenses needed to achieve the image goals and what hardware is required to achieve the expected image goals.


    Bernice
    Except Wista that makes extension beds and bellows for their field and technical cameras.

  3. #13

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    Re: Chamonix H-1 and Imagon 250mm

    Ok Bob, I'll bite.... once.

    Well Bob, how much "extension" could be put on a Wista field folder... 2000mm or more possible?


    Bernice

    Quote Originally Posted by Bob Salomon View Post
    Except Wista that makes extension beds and bellows for their field and technical cameras.

  4. #14

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    Re: Chamonix H-1 and Imagon 250mm

    Quote Originally Posted by Bernice Loui View Post
    Ok Bob, I'll bite.... once.

    Well Bob, how much "extension" could be put on a Wista field folder... 2000mm or more possible?


    Bernice
    Believe max is about 2000mm.

  5. #15

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    Re: Chamonix H-1 and Imagon 250mm

    How about 6,000mm Bob?

    Bernice


    Quote Originally Posted by Bob Salomon View Post
    Believe max is about 2000mm.

  6. #16

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    Re: Chamonix H-1 and Imagon 250mm

    Quote Originally Posted by Bernice Loui View Post
    How about 6,000mm Bob?

    Bernice
    Been too long since I sold them but there could be a 6K bed and bellows.

  7. #17
    Drew Saunders drew.saunders's Avatar
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    Re: Chamonix H-1 and Imagon 250mm

    Quote Originally Posted by olk View Post
    Thank you - I missed to take into account that the lens is mounted at the back of the shutter.
    I'm wondering because with f=276mm I get a little bit different distances (312,5mm for 2.5m distance). I used the simple lens formula: 1/b + 1/c = 1/f (b: distance subject, c: distance image, f: focal length).
    Focal length is still 250mm, so to focus at 2500mm, itís
    1/250 - 1/2500 = 0.0036
    1/0.0036 = 277.77777

    You need to rack out 28mm from your starting point of 276mm or 304mm.

    Telephoto lenses work the other way, your starting point is much less than the focal length, but any 250mm lens focused at 2500mm needs to move the rear nodal point forward 28mm, whether by bellows, focusing helicoid, or internal focusing wizardry of modern lenses.


    Sent from my iPad using Tapatalk
    https://www.flickr.com/photos/drew_saunders/

  8. #18

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    Re: Chamonix H-1 and Imagon 250mm

    Quote Originally Posted by drew.saunders View Post
    You need to rack out 28mm from your starting point of 276mm or 304mm.
    thanks, I got it.

    So I've to think about the camera. The Chamonix H-1 can not be extended and the F2 is in stock in 4 months (or maybe later) ...

    A Sinar F2 is suitable but heavier - portable/lightweight enough for hiking (photographing landscape)?

  9. #19

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    Re: Chamonix H-1 and Imagon 250mm

    Change the focal length if the camera is not long enough. A +1 diopter could be what you need if you don't want to use a prolonged lens board.
    I am sure someone can present a distance piece for the back in a couple of weeks

    Sent fra min SM-G975F via Tapatalk

  10. #20

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    Re: Chamonix H-1 and Imagon 250mm

    All view cameras are a fixed set of trade offs, there IS NO ideal view camera for all image making needs.

    ~If you're back packing long distances for very extended durations, this image making needs mostly demands a light weight field folder with small light weight lenses, tripod and all related view camera items to meet this requirement. Traded off, large aperture lenses that are not light weight, camera with limited movements with limited camera/bellows extension and camera/bellows compression to allow using wide angle lenses with significant camera movement.

    ~Monorail camera such as the Sinar F2 has FAR more camera/bellows extension and camera compression, camera movements than ANY field folder. This allows using nearly ANY optic in the Sinar system. Couple this with the Sinar shutter allows using barrel lenses. Modularity allows configuring the camera as needed to meet most any view camera image making need. Sinar monorail system is no where near as compact/foldable as a lightweight field foldable and can never be folded up into essentially a box for compact and ease of transport.

    Take the time to read this before deciding.
    https://www.largeformatphotography.i...ar-Norma-(4x5)


    Again, primary or top priority is deciding the kind of images you're interested in making, the lenses-optics needed to achieve this, then consider which style of view camera meets the majority of these needs and demands most.



    Bernice


    Quote Originally Posted by olk View Post
    thanks, I got it.

    So I've to think about the camera. The Chamonix H-1 can not be extended and the F2 is in stock in 4 months (or maybe later) ...

    A Sinar F2 is suitable but heavier - portable/lightweight enough for hiking (photographing landscape)?

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