• 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.
Feel the intensity, not your equipment. Maximum image quality. Minimum weight. The new ZEISS SFL, up to 30% less weight than comparable competitors.

1. General Optical Design (1 Viewer)

Objective lens, focusing lens, image-erecting system and eyepiece – the key elements found in all binoculars for birding and nature observation. Each component has its own special job: The objective lens generates an image of the observed object at the intermediate image plane. This image is upside down and reversed left-to-right, so the prism system is positioned in front of the intermediate image plane and this corrects the image for both top to bottom, and left to right orientations. The result is an upright, unreversed image. Prisms are used in both binoculars and spotting scopes for this purpose. The eyepiece acts as a magnifier and helps the eye to examine the image.

Representation of the optical path in the binocular body.

Representation of the optical path in the binocular body.

Theoretically, one converging lens each for the objective lens and eyepiece is enough, but the result would be a crude and unsatisfactory instrument. Therefore, sophisticated systems have been developed which contain, for example, up to 12 lens elements or more for binoculars (Victory SF 8x32) on each side, or up to 17 lens elements for spotting scopes with zoom objectives (Harpia 95 with 23-70x eyepiece). Different glass materials with varying properties are also combined (including the very high- quality optical fluoride glass for ZEISS FL lenses) to achieve brilliant, outstanding results. The many coatings applied to all glass surfaces in a high vacuum and, of course, extremely stringent tolerances in the manufacture of each part, and during assembly, play key roles as well.
Warning! This thread is more than 2 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread