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Camera's Dynamic Range Question

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  • Wayne Cooper
    Skimming thru Ron s 1st book this evening the subject Dynamic Range came up. Pg 435-436 Chpt 9. Galaxy image processing. Very interesting. The dynamic range
    Message 1 of 3 , Dec 31, 2004
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      Skimming thru Ron's 1st book this evening the subject "Dynamic
      Range" came up. Pg 435-436 Chpt 9. Galaxy image processing. Very
      interesting. The dynamic range of a ccd camera determines the
      brightness levels the camera is able to record in an object. A
      camera with a small dynamic range will record mostly extreme black
      or white and miss all of the nice shades in between. Sbig states
      that the "dynamic range" of a camera can be estimated by dividing
      the camera's full well capacity by the read noise.

      I have an ST2000XM camera. Sbig updated the chip used in this
      camera. The fullwell capicity has not changed....but the read noise
      has been cut in 1/2. I thought nothing of this and did not think it
      was a big deal untill now. Does this mean the newer ST2000XM camera
      has *twice* the dynamic range then the older model. If so will the
      newer camera now produce images that have a dramatic increase in the
      long scale contrast...in escence displaying all of those subtles
      shades of grey that may be missed by the older model. Sounds like
      their should be a 100% increase in the camera's dynamic range.I
      would think this would be the main advantage of lower read noise???
      Dynamic range is not mentioned anywhere in Sbigs advertisment for
      this camera. Will this increase be visually apparant in a side by
      side comparison...or is their something more important about the
      lower read noise other then the dynamic range? Thanks, Wayne
    • Wodaski Yahoo
      Dynamic range is good to have, but not as dramatically important as other things (like low noise). Low noise does give you a greater dynamic range, but other
      Message 2 of 3 , Dec 31, 2004
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        Dynamic range is good to have, but not as dramatically important as other
        things (like low noise). Low noise does give you a greater dynamic range,
        but other aspects of low noise are much more important.

        The beauty of a large dynamic range is that you can simultaneously capture
        bright stuff and dim stuff, and retain detail in both. So having 100% more
        dynamic range means that you will have fewer saturated stars. The low noise
        that creates this increased dynamic range will contribute something far more
        valuable: the dim details will have less noise, and there will be more steps
        _inside_ that particular range of data. In other words, subtle details will
        be easier to see with a given exposure time. So the extra steps pay off in a
        second way, too.


        Ron Wodaski
        The New CCD Astronomy
        http://www.newastro.com/ipb

        -----Original Message-----
        From: Wayne Cooper [mailto:coopersx@...]
        Sent: Friday, December 31, 2004 9:54 PM
        To: ccd-newastro@yahoogroups.com
        Subject: [ccd-newastro] Camera's Dynamic Range Question



        Skimming thru Ron's 1st book this evening the subject "Dynamic
        Range" came up. Pg 435-436 Chpt 9. Galaxy image processing. Very
        interesting. The dynamic range of a ccd camera determines the
        brightness levels the camera is able to record in an object. A
        camera with a small dynamic range will record mostly extreme black
        or white and miss all of the nice shades in between. Sbig states
        that the "dynamic range" of a camera can be estimated by dividing
        the camera's full well capacity by the read noise.

        I have an ST2000XM camera. Sbig updated the chip used in this
        camera. The fullwell capicity has not changed....but the read noise
        has been cut in 1/2. I thought nothing of this and did not think it
        was a big deal untill now. Does this mean the newer ST2000XM camera
        has *twice* the dynamic range then the older model. If so will the
        newer camera now produce images that have a dramatic increase in the
        long scale contrast...in escence displaying all of those subtles
        shades of grey that may be missed by the older model. Sounds like
        their should be a 100% increase in the camera's dynamic range.I
        would think this would be the main advantage of lower read noise???
        Dynamic range is not mentioned anywhere in Sbigs advertisment for
        this camera. Will this increase be visually apparant in a side by
        side comparison...or is their something more important about the
        lower read noise other then the dynamic range? Thanks, Wayne








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      • Wayne Cooper
        Thanks for explaining this. Much appreciated. Sincerely, Wayne And Have a Happy New Year ... as other ... range, ... capture ... 100% more ... low noise ...
        Message 3 of 3 , Dec 31, 2004
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          Thanks for explaining this. Much appreciated. Sincerely, Wayne
          And Have a Happy New Year

          --- In ccd-newastro@yahoogroups.com, "Wodaski Yahoo" <yahoo@n...>
          wrote:
          > Dynamic range is good to have, but not as dramatically important
          as other
          > things (like low noise). Low noise does give you a greater dynamic
          range,
          > but other aspects of low noise are much more important.
          >
          > The beauty of a large dynamic range is that you can simultaneously
          capture
          > bright stuff and dim stuff, and retain detail in both. So having
          100% more
          > dynamic range means that you will have fewer saturated stars. The
          low noise
          > that creates this increased dynamic range will contribute
          something far more
          > valuable: the dim details will have less noise, and there will be
          more steps
          > _inside_ that particular range of data. In other words, subtle
          details will
          > be easier to see with a given exposure time. So the extra steps
          pay off in a
          > second way, too.
          >
          >
          > Ron Wodaski
          > The New CCD Astronomy
          > http://www.newastro.com/ipb
          >
          > -----Original Message-----
          > From: Wayne Cooper [mailto:coopersx@c...]
          > Sent: Friday, December 31, 2004 9:54 PM
          > To: ccd-newastro@yahoogroups.com
          > Subject: [ccd-newastro] Camera's Dynamic Range Question
          >
          >
          >
          > Skimming thru Ron's 1st book this evening the subject "Dynamic
          > Range" came up. Pg 435-436 Chpt 9. Galaxy image processing. Very
          > interesting. The dynamic range of a ccd camera determines the
          > brightness levels the camera is able to record in an object. A
          > camera with a small dynamic range will record mostly extreme black
          > or white and miss all of the nice shades in between. Sbig states
          > that the "dynamic range" of a camera can be estimated by dividing
          > the camera's full well capacity by the read noise.
          >
          > I have an ST2000XM camera. Sbig updated the chip used in this
          > camera. The fullwell capicity has not changed....but the read
          noise
          > has been cut in 1/2. I thought nothing of this and did not think
          it
          > was a big deal untill now. Does this mean the newer ST2000XM
          camera
          > has *twice* the dynamic range then the older model. If so will the
          > newer camera now produce images that have a dramatic increase in
          the
          > long scale contrast...in escence displaying all of those subtles
          > shades of grey that may be missed by the older model. Sounds like
          > their should be a 100% increase in the camera's dynamic range.I
          > would think this would be the main advantage of lower read
          noise???
          > Dynamic range is not mentioned anywhere in Sbigs advertisment for
          > this camera. Will this increase be visually apparant in a side by
          > side comparison...or is their something more important about the
          > lower read noise other then the dynamic range? Thanks, Wayne
          >
          >
          >
          >
          >
          >
          >
          >
          > Yahoo! Groups Links
          >
          >
          >
          >
          >
          >
          >
          >
          >
          > __________ NOD32 1.962 (20041231) Information __________
          >
          > This message was checked by NOD32 antivirus system.
          > http://www.nod32.com
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