• 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. tenex

    Dioptre Setting: Fallacy and Fact

    No Bill, Helmholtz did... and apparently the idea was accepted for a long time. Exactly where the eye's resting focus is might not seem to matter in the use of afocal instruments, but perhaps the fact that it's so close helps to explain why we have such issues with diopter setting? Anything...
  2. tenex

    Dioptre Setting: Fallacy and Fact

    If you stop to think about it (apologies to Helmholtz who may not yet have known about evolution?), having the relaxed focus at infinity seems an unlikely result when most important events and tasks involve much shorter ranges. Also it would be difficult to make corrections for any reason if...
Back
Top