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Thread: anyone tried these c-mount lenses

  1. #1
    Senior Member viablex1's Avatar
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    anyone tried these c-mount lenses


  2. #2
    Senior Member RichA's Avatar
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    Re: anyone tried these c-mount lenses

    Quote Originally Posted by viablex1 View Post
    The 35mm and 75mm models are useless, they will only give you a small illuminated circle because they aren't made to cover a 1" sensor. The 12.5mm will also vignette (you'll get about a 16mm equivalent after cropping a rectangle) and none of them may work owing to the mounting back not fitting into c-mount adapters available. The motorized units won't work at all as they are controlled via cables to the CCTV camera. Their aperture's normal resting state is fully closed. Lastly, why pay B&H $300/ea for generic (don't know who makes them) lenses when they can be had surplus for $20-$50?
    If you'd like to buy lenses that will cover the whole image circle, check out sources like Edmund Optics for units that will cover a 1.3" CCTV sensor. They won't be cheap. But go to Ebay first and type in "c mount lens." See what comes up.

  3. #3
    Senior Member viablex1's Avatar
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    Re: anyone tried these c-mount lenses

    okay cool thanks I am just starting to check out this area , any recommendations as to brand?

  4. #4
    Senior Member RichA's Avatar
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    Re: anyone tried these c-mount lenses

    Quote Originally Posted by viablex1 View Post
    okay cool thanks I am just starting to check out this area , any recommendations as to brand?
    Fujinon, Pentax (Cosmicar, Computar), Schneider, Angenieux, Sony, and a host of European lenses like Som Berthiot and Kern Switar (Kodak as well) used for 16mm that are c-mount. Generally, the lenses used for 16mm film cameras do a better job of coverage and will mount into current micro 4/3rds adapters without modification. The Cosmicar 12.5mm (Pentax) 12.5mm f1.4 (for example) needs some minor machining done to its rear cell to make it focus at infinity.
    Most of the time, the sellers do not provide info on what size sensor (you need at least a lens made to cover a 1" CCTV sensor) the lens was made for, nor do they provide the dimension of the rear lens cell to let you know if it will fit in the standard c-mount to micro 4/3rds adapter. The back needs to be no more than 36.5mm wide to fit.
    For instance, in this group, (from left to right) the silver Schneider 25mm fits, the 12.5 Cosmicar does not, the older Cosmicar next to it does, the Fujinon was modded to fit and the Zeiss Tevidon does not fit.



    This site has the 12.5mm Cosmicar and Computer Pentax lenses for a very low price. But both will require some modding to the rear.

    http://www.surplusshed.com/pages/cat...alenses_1.html

  5. #5
    Abbazz
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    Re: anyone tried these c-mount lenses

    B&H website is wrong about the coverage of these lenses, as the CF***HA-1 lenses are designed to cover a 1" sensor, which is a bit smaller (9.6 x 12.8 mm) than Micro-4/3rds format (13.5 x 18 mm). I have never tried these lenses but guess the 12.5/1.4 and 16/1.4 will not cover Micro-4/3rds (circular image), while the 25/1.4 will exhibit a bit of vignetting (I think it's the newer version of the lens described in this thread) and the longer focal lengths (35/1.4, 50/1.8 and 75/1.8) will cover the whole frame.

    The problem with these lenses is that the CF***HA-1 series are the lower grade lenses designed for 1.5 megapixel CCTV cameras, so I guess you have to test their image quality to make sure it's adequate for still cameras. The Fujinon HF***HA-1B and HF***SA-1 series are the "high resolution" grade lenses but unfortunately they are reported to cover only 2/3" sensors (6.6 x 8.8 mm), which is likely not enough to offer acceptable coverage for Micro 4/3rds cameras, except maybe for the longest focal lengths.

    Cheers!

    Abbazz

  6. #6
    MelanieC
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    Re: anyone tried these c-mount lenses

    I have the Fujinon HF25HA. It does not cover the entire sensor but for some shots I don't mind and the rest of the time I shoot in square, which I like doing anyway. It does not need to be modified. I got it for under $75 new in box.


    a shot in which the vignetting doesn't matter


    so you can see the vignetting


    the corners are still dark if you shoot in square

    I'm in the market for the Pentax 25mm/1.4 that is backordered on B&H because it appears to be similar and covers more of the sensor. If the Fujinon didn't vignette I would consider it a perfect everyday lens -- I like its qualities, it's very sharp, my favorite focal length, and very easy to focus.

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