- Compact Binoculars: Objective lens size is less than 30mm (8×25, 10×28, etc.)
- Midsize: Objective lens size is from 30mm to 40mm (10×30, 8×32, etc.)
- Full-size: Objective lens size is greater than 40mm (8×42, 10×50, etc.)
binoculars, optical instrument, usually handheld, for providing a magnified stereoscopic view of distant objects. It consists of two similar telescopes, one for each eye, mounted on a single frame. … Binoculars are designed to give an upright view that is correctly oriented left-to-right.