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Camera Specifications computing focal length and f/#

  1. Jul 2, 2013 #1
    So I have come across a specification of a narrow field of view camera. The specification states
    IFOV=30 microrad
    resolution=<.1m at 1 km

    If I assume a 1K sensor at 9micron pitch and an aperture = 3.7cm

    I have resolution at .013 m

    Chip size = 9.2mm

    Focal length is 6.167E5mm?? can this be right? Also f/#=1.6E4

    Do I have the formulas correct

    f/#=Focal Length/Aperture

    Focal Length=Aperture/2*tan(IFOV)
  2. jcsd
  3. Jul 3, 2013 #2

    Andy Resnick

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    Can you provide additional information- for example, the field of view = 2x2 what- radians, degrees, other? Any specific information on the lens?

    Alternatively, do you have a product ID/name?
  4. Jul 3, 2013 #3
    Hi Andy,

    Actually the only thing specified is the IFOV, FOV and resolution at 1Km I think it is up to the supplier to design the rest. FOV is degrees. I assumed a sensor 1K sensor at 9 microns.
  5. Jul 5, 2013 #4

    Andy Resnick

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    It's still not entirely clear- are you specifying a sensor, a lens, or an integrated sensor+lens? The IFOV and FOV specs define the sensor array size (I also got a 1k x 1k array), but the resolution spec involves a lens (which will operate at f/15 at a magnification of 1*10^-6, according the spec and assuming you are using visible light), and combining everything indicates a 400mm focal length lens, if the pixel size is 9um.

    Note- imaging over 1 km distance is complicated by atmospheric distortion, you are unlikely to meet your resolution spec unless your application is able to avoid this. Some friendly advice- providing the OP specs to a supplier will result in an irritated supplier.
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