binoculaire

Binoculaire is the French adjective meaning binocular or two-eyed. In optics, it describes devices that provide two parallel optical channels to the observer, enabling stereo vision. The term appears in French for both general two-eyed viewing and for specific instruments such as the microscope binoculaire (binocular microscope) and, commonly, binoculars (jumelles).

Binoculars are handheld instruments designed for magnified, two-eyed viewing of distant objects. Specifications express magnification and objective diameter, often written as M×(Ømm), for example 8×42. Higher magnification improves detail but reduces brightness and steadiness; larger objectives increase light gathering and weight.

Optical designs use prisms to invert and orient the image. The two main styles are Porro and roof prisms. Porro prisms give a wider, offset shape; roof prisms allow a straighter, slimmer body. Lenses are coated to improve light transmission; many models are waterproof and nitrogen- or argon-filled to prevent fogging.

Applications and selection: use includes wildlife observation, astronomy, marine navigation, and outdoor recreation. Choose by purpose, weight, and budget. Eye relief matters for eyeglass wearers; adjustable eyecups help. Binoculaire devices cover a broad category of two-eyed optical instruments, distinct from monoculars and single-tube spotting scopes.