the mag the Sony 4 lux camera is capable of seeing

From: Tom Wagner (sciteach@mchsi.com)
Date: Wed Jun 04 2003 - 00:39:42 EDT

  • Next message: Björn Gimle: "Re: the mag the Sony 4 lux camera is capable of seeing"

    Hello,
    
    So that I may know what to expect when trying to record flashing satellites
    etc. I did some starlight magnitude tests with my Sony digital video camera
    [DCR TRV 340]. Following are the results.
    
    The lens setting was 50 mm, F 2.4 at 20X magnification.
    The imaging device is a 1/6", 460K gross pixels CCD.
    The video was actually 290K Pixels.
    The minimum illumination capable of being perceived is 4 Lux
    Using the so-called "NightShot" mode I could barely see a star that was mag.
    +3.
    Using the "Super NightShot" mode I could barely see a star that was mag. +6.
    
    I have not yet tried the "Color Slow Shutter." At least I don't think I did.
    :~)  I'm just learning how to use the camera.
    
    Using the Super NightShot mode the shutter speed must have been the slowest
    the camera can shoot at, that is 1/4 second. In this mode any movement of
    the camera made the bright stars streak momentarily. The image appeared to
    be stepped at 1/4 second intervals and was very noisy indeed.
    
    According to Sony the Super NightShot mode is about 16 times brighter than
    straight NightShot.
    
    Now can someone tell me how 16 times correlates to 3 magnitudes in
    brightness?
    
    Thanks!
    
    Tom  Iowa  USA
    .....
    
    P.S. I recently drilled holes in a board and mounted my digital video
    camera, next to my binoculars, next to my night vision scope, next to my
    Coolpix digital camera. On the board I also have an angle finder to
    approximate the altitude so as to zero in on flashing geosyncs with minimal
    star-hopping needed in my light polluted skies. I will use it on a tripod
    and aim it at Superbird A (and others). When I see the satellite flashing in
    the 2X night vision scope I will look for it in the 7X binoculars. When I
    center it in those I will know that it is centered in my video camera, even
    at 20X. I will then try to video tape the flashes. I may be able to use the
    Coolpix for in some way too.
    
    I sometimes have a difficult time spotting Superbird A in my binoculars but
    find it easy to spot with the 2X night vision scope. Now I can find it first
    in one then in the other. Without this setup I do not believe I could find
    the intermittent flashes of Superbird A at 20X using my video camera. Now if
    the clouds would go away I would be all set!
    
    
    
    
    
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