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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

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  1. J

    Used ED82

    Hi, so some overcorrection seems to be present. I assume the star test was with a real star from the time, so SA introduced by too close artificial star is out (the ED50 might still fare ok with an artificial star at the same distance). This link shows lambda/4 (barely diffraction limited) and...
  2. J

    Used ED82

    Hi, I would strongly recommend a star test - either on a cool overcast day with an artificial star at 30m or so or before sunrise during a clear night. In both cases the scope should have been outside for a few hours to cool down to ambient temperature. Joachim