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

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    Example with a 90mm Maksutov-Cassegrain type scope

    Most commercial Cassegrain types whether Schmidt or Maksutov actually use a knob on the back which moves the mirror up and down along the optical path. This is useful(for astronomy at least) in that you can put a lot of equipment such as filter boxes oroff axis guiders and still be able to focus...
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    Example with a 90mm Maksutov-Cassegrain type scope

    Mak Newts have a smaller secondary mirror as a rule, and therefore tend to be somewhat better in terms of contrast. The primary mirror is actually slower than in a Cassegrain at around F6 (compared to about F3) and this also makes the mirror easier to fabricate and being slower, optical...
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