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    Fotographs (was: Daytime Venus)
    From: Alexandre Eremenko
    Date: 2012 May 3, 18:22 -0400

    Very nice photo.
    This reminds me what I recently read in the History of Air Navigation.
    How to take an accurate star altitide over the natural horizon without
    a sextant?
    Photograph it together with the horizon, and measure the
    altitude with a ruler:-)
    
    The book says the method was actually tried in the early days of air
    navigation. On the airships, where there is enough
    space and comfort
    to develop the plates quickly.
    
    Alex.
    
    On Thu, 3 May 2012, Greg Rudzinski wrote:
    
    >
    > A better image of todays sunspot. Taken with a 200 mm Pentax lens.
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