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Stargazing Amateur Astrography

  1. Sep 22, 2016 #1

    Andy Resnick

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    Astrographs are fast (f/4 or less) telescopes with large image circles (say 60mm or more); there are optical design considerations that make the specific designs somewhat more complex than 'regular' telescopes- primarily the strict field flatness requirement. While a 35mm format sensor is significantly smaller than medium-format plates associated with astrographs, by stitching together a few fields of view I can begin to approach that kind of performance. Here's 2 fields of view stitched (using Hugin), each image (stack) taken with a 400mm lens, providing an overall 5 x 5-degree field of view of the North American Nebula in Cygnus:


    This image has been so severely downsized that it's hard to really appreciate; there are at least 408k stars filling in 8.5% of the image. If I printed this at maximum size (80 dpi), it would be 8 feet on a side- enough to cover a wall with this level of detail:

  2. jcsd
  3. Sep 25, 2016 #2
    Nice work Andy! Anyone else take any Astrographs?
  4. Sep 25, 2016 #3


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    Am looking at buying a f4 astrograph with either a 6" or 8" mirror. This will have a distinct advantage over my 9.25", f10 scope

    just have to recover from the hugely expensive Christmas holiday airfares :frown:
    for what that is costing me, I could buy 2 x 8" f4 astrographs optical assemblies

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