Sensor Type: CCD vs. CMOS - Opinions?

Discussion in 'Digital Photography' started by Alan Wonsowski, Jan 31, 2004.

  1. I have been "shopping" for a digital camera and have used the
    "dpreview.com" web site to obtain comparative information. The sensor
    type varies from manufacturer to manufacturer. Two questions:

    1. What does the sensor do?

    2. What are the pros and cons regarding CCD type sensors vs. CMOS?

    Opinions welcomed.

    Thanks,
    Alan
     
    Alan Wonsowski, Jan 31, 2004
    #1
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  2. Alan Wonsowski

    steve Guest

    The sensor acts like the film in a regular camera, and converts the
    light to a 'permanent' image -- in this case a digital representation of
    one.

    As for CMOS vs CCD, just check out sample images from the various
    cameras that strike your fancy. www.dpreview.com is one place to start.

    steve
     
    steve, Jan 31, 2004
    #2
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  3. Alan Wonsowski

    Ron Hunter Guest

    The sensor is the digital 'film'. It converts the light falling on it
    to electricity and this is converted to digital information. Sensors
    also are used for other purposes in most cameras, such as focusing and
    measuring the light coming in through the lens.

    CCD type sensors are lower noise and are quite common in better cameras.
    CMOS is cheaper, can have smaller pixels (sensor elements), but have a
    problem with higher electronic noise. Until recently, only the cheapest
    cameras used them, but new ways of handling the higher noise rates
    electronically, and via software, have caused makers of higher priced
    cameras to start using them.

    Cameras, film or digital, are a series of creative compromises and
    different makers have different ideas of what makes the best overall
    package. A good lens coupled with an average sensor will give average
    results. No camera is better than the lens in front, and no lens can
    help if the sensor is lousy, the electronics are of poor quality, or the
    software (firmware) is poor.

    The best idea is to check out user reports, professional reviews (and
    remember ALL reviewers are biased), and the sample pictures. Then go to
    a store and HANDLE the camera. If it isn't comfortable, no quality of
    lens, or plethora of functions, will make you like using it.
     
    Ron Hunter, Jan 31, 2004
    #3
  4. Alan Wonsowski

    Mark Herring Guest

    What are some examples of low end cameras using CMOS?

    Another factor: CMOS is easier to make in large areas (manufacturing
    yield issue). For a given resolution, a physically larger sensor
    gives higher optical throughput**, which--depending on the noise---may
    give higher signal to noise ratio.

    **throughput (AKA "etendue" or "A-omega") is defined in one of 2 ways:

    1. product of the sensor pixel area and the solid angle subtended
    by the exit pupil (crudely--the square of the inverse f/#)

    2. product of the input pupil area and the solid angle subtended
    by the pixel in object space.

    Using definition (1), we see that there are two options for increased
    throughput: Faster optics or larger sensors. Once the optics are in
    the range of f/1.4 to f/2, it may be much cheaper to make a larger
    sensor. With zooms, it's hard to get useable fast optics at any
    price.
    **************************
    Mark Herring, Pasadena, Calif.
    Private e-mail: Just say no to "No".
     
    Mark Herring, Jan 31, 2004
    #4
  5. Alan Wonsowski

    Paolo Pizzi Guest

    Just about every webcam.
     
    Paolo Pizzi, Jan 31, 2004
    #5
  6. It's short for "photosensor"--the part of the camera that is sensitive to
    light, that senses the image. (See where the name comes from?)

    The lens projects light onto the sensor, and the sensor measures that light,
    in millions of locations.

    To compare with a film camera, film is both the "sensor" which senses light
    and the "storage medium" which records and saves the images. Digital cameras
    separate these two functions into a photosensor and flash memory for
    storage.
    There are pros and cons for the manufacturer, but none that matter for you.
    CCD vs. CMOS sensors shouldn't even be on the list of things that you
    consider when shopping for a camera.

    -Mike
     
    Michael Geary, Jan 31, 2004
    #6
  7. Alan Wonsowski

    Ron Hunter Guest

    Creative webcam/pocket digital camera. Several other models in the
    under $75 range. VERY noisy pictures, even in good light.
     
    Ron Hunter, Jan 31, 2004
    #7
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