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    Re: Comet Donati above Paris 1858
    From: Robin Stuart
    Date: 2019 Apr 21, 11:56 -0700

    Brad,

           As the introductory quotation in my post was supposed to make clear, my remarks were limited solely to the capabilities of modern cameras to capture the night sky with relatively short exposures. Whether foreground objects are also captured depends on the level ambient lighting.

    You stated:

     “It is for this reason we never see stars simultaneously with the moon landings.  The foreground effectively washes out the background.  Image after image from the surface of the moon, with no stars in the background.”

    Since the Apollo astronauts had the good sense to land during daylight hours, exposure times were quite short. If they had stuck around after lunar sunset (luckily none of them had to) and tried taking photos of stars with the same exposure and aperture as they had used in daylight they wouldn’t have captured any stars either. Try pointing an old film camera at the sky at night on Earth with, say, a 1/100s exposure and see how many stars you pick up!

    Robin Stuart

       
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