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

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    Telescope light transmission figures

    Taking into account refractor secondary spectrum and transmission loss in glass. Refractor uncoated objective, uncoated eyepiece transmission 62%. Coated objective and coated eyepiece 79%. Cemented objective, coated objective, coated eyepiece 81%. Newtonian reflector including losses due to...
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    Telescope light transmission figures

    Coated opera glasses and coated astro refractors with inverted images may have transmission figures above 95%. However, Newtonian reflectors with ordinary mirrors may have transmissions of 70% to 80%. The same with compound telescopes. One can get enhanced mirror coatings but for 200 years or...
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