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    50mm Camera Altitude Using Short Horizon
    From: Greg Rudzinski
    Date: 2010 Jun 21, 20:20 -0700

    The linked image #8373 shows the morning Sun's upper limb 20°23.8' (3267 pixels) above the horizon which is 300 yards away. Height of eye is 6 feet. Using the 1975 edition Bowditch formula for table 22 a dip correction of 22.7' minutes of arc is derived to be subtracted from Hs. The Ho for an upper limb Sun is then 19° 42.7'.

    Hs 20°23.8'
    U.L.corr. -18.4'
    Dip Short corr. -22.7'
    UT 14:32:52
    Date 6/20/2010
    GPS Lat 34°10.4'N
    GPS Lon 119°13.8'W
    Hc 19°41.0'
    Ho19°42.7'
    INT 1.4' Toward
    Az 74.5°True

    Dip Short Formula (Bowditch)
    .4156 d + .5658 h/d = Dip in moa (to be subtracted)
    d = distance in nautical miles
    h = height of eye in feet
    (.4156)(.15) + (.5658)(6/.15) = 22.7' moa

    This method of taking a sight is not as good as a sea horizon but will allow photographers to try out camera CN if they are near a lake or body of water which is 200 or more yards across.

    Greg Rudzinski
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