A binocular or binocular (after the Latin prefix bi- for "two" and Latin oculus for eye) is an optical instrument that has an eyepiece for both eyes , ie it presents an image to both eyes. The images for both eyes can be different or identical.
Different images for both eyes
Some devices produce slightly different images for both eyes by creating independent beam paths for both eyes . This stereoscopic vision gives the observer a three-dimensional, three-dimensional impression of depth. The best-known examples of this group are binocular binoculars (binoculars, opera glasses) and the stereo microscope .
Stereo microscopes allow live observations, preparation and sorting work to be carried out with moderate magnification (usually approx. 4 to 40 times). The two separate beam paths hit the object at an angle of approx. 14 °. For good spatial vision, the magnification must not be greater than about 100 times. Stereo microscopes are often called “binoculars” or “binos” for short in German laboratory jargon .
Identical images for both eyes
Other devices duplicate the image so that both eyes see an identical image. This enables more relaxed, fatigue-free observation, but does not convey any additional information. One example is the binocular tube on high-quality light microscopes . It is therefore a component of the entire device.
Monocular and trinocular
A trinocular tube or phototube for light microscopes has, in addition to the two eyepieces for the eyes, another output to which a camera can be connected.
- Binocular vision
- binocular rivalry
- Space perception , stereoscopic vision
- Stereo display , anaglyph 3D
- Gerhard Göke: Modern methods of light microscopy: from transmitted light bright field to laser microscopes . Franckh'sche Verlagshandlung, Stuttgart 1988, ISBN 3-440-05765-8 , p. 80 .
- Dieter Gerlach: The light microscope. An introduction to function and application in biology and medicine . 2nd Edition. Thieme Verlag, Stuttgart 1985, ISBN 3-13-530302-0 , p. 14th f .