Q.Why is a prism binoculars preferred over traditional binoculars? Describe its working in brief.

[!TLDR] Ordinary two-cylinder binoculars are limited in field of view by human eye spacing; prism binoculars use TIR-based right-angled prisms to let the wider objectives feed narrower, eye-spaced eyepieces. [!ANSWER] Overcomes the eye-spacing limit on objective separation; two right-angled isosceles glass prisms …

Ordinary binoculars built from just two straight cylinders are limited in field of view (and in the sense of depth/stereopsis they can provide) because the distance between the two objective lenses cannot be made any wider than the fixed distance between the two human eyes -- the eyepieces must stay eye-spaced, and with simple cylinders the objectives are forced to match. Prism binoculars overcome this by placing two right-angled isosceles glass prisms inside each barrel, positioned so the light entering the (widely-spaced) objective undergoes total internal reflection at each prism's hypotenuse face in turn -- the prism's internal angle of incidence, about 45 degrees, comfortably exceeds glass's critical angle of about 42 degrees, guaranteeing genuine TIR (not partial reflection) at every bounce, with essentially no light loss. This arrangement effectively 'folds' the optical path between a WIDE objective and a NARROW (eye-spaced) eyepiece, letting the objective lenses be spaced much farther apart than the eyes themselves -- widening the effective field of view and significantly improving the perceived sense o …

Identify the specific limitation of simple binoculars (objective spacing capped by eye spacing), then explain how the two TIR prisms per bar …

Describing prism binoculars only as 'better quality' or 'clearer image' without identifying the actual specific limitation (eye-spacing- …