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

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  1. W

    Curio 7x21 vs. CL 8x25 pocket

    Talking about low light, dilated pupil performance. If you think of an objective lens (usually lenses) with no binoculars behind it it doesn't matter how big it is, they're all more than 7mm - it's the jiggery pokery behind it that makes it brighter or dimmer, primarily with modern glass and...
  2. W

    Curio 7x21 vs. CL 8x25 pocket

    Brightness is dependent on transmission and exit pupil size. Exit pupil size is aperture divided by magnification and transmission is measured by someone with access to some rather expensive equipment, it's also usually stated by the manufacturers. If you think of it this way- your eyes on...
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