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  1. Omid

    blackouts at AFOV of greater than 60 degrees- why

    No problem, and you are welcome :)
  2. Omid

    blackouts at AFOV of greater than 60 degrees- why

    Hi Kimmik, Thank you for the clarification. OK, so you experienced blackouts on the smaller size NL models. Your experience could be due to the small exit pupil size and, in addition, spherical aberration of the exit pupil and, further due to vignetting of the field rays. I am afraid your...
  3. Omid

    blackouts at AFOV of greater than 60 degrees- why

    As I said, I have no opinion on whether NL binoculars have black-out problems or not. I don't own these models and I don't follow their reviews or user opinions. So, have you experienced blackouts while looking through Swarovski NL binoculars? And then you have tested their eyepieces for...
  4. Omid

    blackouts at AFOV of greater than 60 degrees- why

    I didn't say anything about Swarovski NL binoculars; what I mentioned are general facts of visual optics :)
  5. Omid

    blackouts at AFOV of greater than 60 degrees- why

    Spherical aberration of the exit pupil is the main cause. Yet, another cause is vignetting of the field beams coming from the edges of field of view. Up to 50% vignetting is considered OK in designing visual instruments: your binoculus might create a nice 5mm circular exit pupil for the central...
  6. Omid

    blackouts at AFOV of greater than 60 degrees- why

    Ed (Elkcub) gave the accurate technical answer in post # 11. I will add one more point: The eye does not see a wide angle field of view all at once as in a wide-angle camera. It rotates and scans the field (the sharp field of view of human eye is about 1 degree). The entrance pupil of the eye...
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