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

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  1. J

    Star Test Result Question

    Hi all, I found one good article for star test for modern ED fast scope, the link as follows: https://www.altairastro.help/star-testing-a-modern-ed-doublet-refractor-with-altair-camera/ Jay
  2. J

    Star Test Result Question

    Hi CMB, I did star test of five scopes (from 50mm- 99mm, Nikon ED and Kowa fluorite) out of curiosity. I got exactly the same results as you observed: the inner focus pattern is clear and out focus pattern is barely visible. Did some search online and found many discussions of refactor star...