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    Re: Daytime Photographs of Aldebaran and Sirius
    From: Peter Monta
    Date: 2016 Aug 7, 15:29 -0700
    Here's a shot of Spica from yesterday afternoon with the Sun about 4 degrees above the horizon.  The animated GIF shows five frames, with the star moving as expected at the sidereal rate (fixed tripod).  85mm lens with 2x teleconverter, f/8 effective, about 1/40 second, RAW mode.  The star is a bit undersampled.

    I've got a deep red filter on order, so we'll see how that works out.  It may do nothing, since I'm not sure I want to remove the IR filter or deBayer the sensor on my camera.

    I've left the color as natural, but it does help a lot to extract the green channel and stretch the contrast a bit more (in a viewer such as ds9).

    Next step Polaris at noon.

    It's helpful to modify any ordinary photo tripod with scales or "setting circles", just adhesive-paper scales with azimuth and elevation.  With the camera on the tripod, one can level up with a smartphone or spirit level, then take an azimuth from a known landmark or the Moon or the Sun (with a cheap eclipse-glasses filter taped to some cardboard in front of the lens).

    My setup is good to about a degree, which allows some confidence in blindly pointing anywhere in the sky.

    Cheers,
    Peter

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