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Thread: IQ180 long exposures

  1. #1
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    IQ180 long exposures

    Been trying some black field exposures (lens cap on). Has anyone else seen the corners brighten as a function of exposure time? At 10 sec I am getting values of 17-30 in the corners and zero elsewhere. Happens on the DF and on tech bodies. I assume the camera is doing its dark field thing so this is puzzling. Attached image has contrast boosted for visibility.
    Last edited by cunim; 2nd December 2013 at 10:42.

  2. #2
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    Re: IQ180 long exposures

    That is heat noise from the sensor.

  3. #3
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    Re: IQ180 long exposures

    Why not shoot a real picture and see how the corners look? Taking a black-frame then having the internal black-frame subtraction is probably what's accentuating it.
    Jack
    home: www.getdpi.com

    "Perfection is not attainable. But if we chase perfection, we can catch excellence."

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