• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Search results

  1. O

    Blackouts and objective lens size - 30/32mm vs. 40/42mm

    Hi - this may be a somewhat elementary question but I wasn't able to find a consistent answer on other sites and other threads. Thanks in advance. Is there a correlation between blackouts or an 'unforgiving' eye box and the size of the objective lens? While this may be different for everyone...