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Thread: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

  1. #1
    Marco Gilardetti's Avatar
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    Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    So, after having long desired to own a portrait-specific lens, I could finally purchase the 250mm Rodenstock Imagon, in Compound 3 shutter. I would like to ask few questions to fellow photographers, in order to get nice images without too much costy and time consuming trial & error at first.

    To begin with, this lens doesn't use the standard "f" values for aperture: everything is calibrated in "h". I'm not familiar with "h" and I would like to understand if, in practice, it is more or less the same, or how should I adjust the lightmeter. (Should anyone have a link to some theory behind "h" values, I would like to read the paper, thank you).

    The second question is if this lens can also be used without any of the "scolapasta" diaphragms in front. I have seen pictures taken with them in which dot highlights are rendered as stars, and I don't really like these kind of cheesy effects. By the way, the hood is basically just a piece of tubing and I can hardly imagine that it wouldn't vignette the image at full aperture. Also, has anyone ever tried to use the Imagon with neutral grey filters to control light, perhaps? I ask because the maximum speed of the shutter is insufficient to deal with sunday light at full aperture.

    Third question: the Compound shutter comes with a magnificent, although uncalibrated, 17-something blades aperture diaphragm. Has anyone ever tried to use the Compound built-in diaphragm instead of the plug-in "scolapasta" accessories? Or is it placed in a wrong position for this type of lens, and won't work well?

    Should anyone have any other kind of comment concerning the use of this lens, I'd be very glad to read. Thank you.

    Click image for larger version. 

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  2. #2

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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    Do a forum search I have answered these questions, and more, several times here.

  3. #3
    Marco Gilardetti's Avatar
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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    It doesn't appear to be so, I'm afraid. A search with "Imagon" as keyword and "Bob Salomon" as author links to this sole thread, where you did not answer to any of these questions:

    http://www.largeformatphotography.in...ghlight=imagon

  4. #4
    No jivin'
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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    It's easier to do a specific search in this forum - for example this: http://www.largeformatphotography.in...enstock+Imagon

  5. #5

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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    Hello Marco !

    The Rodenstock Imagon is a special lens as will be explained below.

    H-numbers are the photometric equivalent of f-numbers for this lens when used with special diaphragms with a central hole and an array of smaller peripheral holes. Hence you should use the H-number exactly like the f-number of an ordinary lens for a proper determination of exposure with your favourite exposure meter.

    The Imagon lens is a doublet, corrected for chromatic aberration but not completely for spherical aberration. When used as an ordinary lens with a central diaphragm, image sharpness somewhat increases when stopping down the lens until diffraction effects become the main source of fuzziness.

    When used with the dedicated diaphragms, the Imagon actually records two images at the same time, a sharp image created by the central part of the diaphragm and a fuzzy image created by light rays crossing peripheral openings, those rays being strongly affected by spherical aberration.

    Hence from an artistic point a view, the image is sharp, but each sharp image point is "surrounded" with a halo of fuzziness.

    If you use the Imagon at full aperture without the special diaphragm, you get an image which is less interesting, it is simply, expressed in modern language, a poor image delivered by a poorly corrected lens

    Regarding the use of the built-in iris in the compound shutter, of course you can use it, you'll probably do not notice anything special due to the fact that the iris is located behind the lens elements and not in front, but again, without the special diaphragms, the behaviour of the Imagon might not be very interesting.

    However, now that you have the lens in front of you, you should feel free to experiment and see which configuration suits you best.

    Attached to this post id an example of image taken with the Imagon with a LF camera, photographer is Michel Guigue (France).

    Out of focus images taken with an Imagon have a strange look, due to the fact that strongly defocused part of the image are created by the projection of the shapes in the diaphragm.
    Attached Thumbnails Attached Thumbnails 2006-guigue-imagon-detail-grossi.jpg   2006-guigue-imagon-detail.jpg  

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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    If you read French, Bernard Sulmon's report http://www.galerie-photo.com/soft-fo...rait-flou.html should interest you. If you don't read French, the images should shed a little light anyway.

    Emmanuel, I'm surprised you didn't suggest this article.

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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    The english language catalogue is here.


    http://www.cameraeccentric.com/html/...enstock_1.html

    Note that the coverage is not magnificent! Yours is OK for 4x5" - but the 360mm version is for 5x7".
    Last edited by Steven Tribe; 3-Oct-2017 at 11:37.

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    Jac@stafford.net's Avatar
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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    Also, has anyone ever tried to use the Imagon with neutral grey filters to control light, perhaps? I ask because the maximum speed of the shutter is insufficient to deal with sunday light at full aperture.
    One of the discs in box should be an ND filter.

  9. #9
    Mark Sawyer's Avatar
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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    Quote Originally Posted by Emmanuel BIGLER View Post
    Regarding the use of the built-in iris in the compound shutter, of course you can use it, you'll probably do not notice anything special due to the fact that the iris is located behind the lens elements and not in front, but again, without the special diaphragms, the behaviour of the Imagon might not be very interesting.
    The iris on the Compound is in front of the lens, though closer than the h/stop discs. The h/stops give a different look called the "Imagon Effect". I prefer using the Compound shutter's conventional iris, which makes the Imagon similar to the Kodak Portrait Lens and other early achromatic meniscus lenses.
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

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    Philippe Grunchec's Avatar
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    Re: Rodenstock Imagon Tiefenbildner 250mm h=5.8, some questions.

    Heinrich Kühn says hello!
    "I believe there is nothing more disturbing than a sharp image of a fuzzy concept!" (Ansel Adams)

    http://philippe.grunchec-photographe.over-blog.com/

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