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

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  1. tenex

    Curio 7x21 vs. CL 8x25 pocket

    It is known that some older people's pupils still dilate significantly more than others'. This could explain some variation in personal experience regarding the advantage of larger objectives in low light.
  2. tenex

    Curio 7x21 vs. CL 8x25 pocket

    How many people buy a pocket bin for use at dawn and sunset?
  3. tenex

    Curio 7x21 vs. CL 8x25 pocket

    Light gathered is a function of objective size. Transmission is a percentage of that, dependent on number of elements, coatings etc, typically close to 90% these days. Perceived brightness is further reduced when the user's pupil (around 2.5mm in daylight) is smaller than the exit pupil...
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