Katana VentraIP

Binoculars

Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal-mounted military models.

Unlike a (monocular) telescope, binoculars give users a three-dimensional image: each eyepiece presents a slightly different image to each of the viewer's eyes and the parallax allows the visual cortex to generate an impression of depth.

Objective lens assembly. This is the lens assembly at the front of the binoculars. It gathers light from the object and forms an image at the image plane.

Image orientation correction assembly. This is usually a prism assembly that shortens the optical path. Without this, the image would be inverted and laterally reversed, which is inconvenient for the user.

Eyepiece lens assembly. This is the lens assembly near the user's eyes. Its function is to magnify the image.

The optical system of modern binoculars consists of three main optical assemblies:[24]


Although different prism systems have optical design-induced advantages and disadvantages when compared, due to technological progress in fields like optical coatings, optical glass manufacturing, etcetera, differences in the early 2020s in high-quality binoculars practically became irrelevant. At high-quality price points, similar optical performance can be achieved with every commonly applied optical system. This was 20–30 years earlier not possible, as occurring optical disadvantages and problems could at that time not be technically mitigated to practical irrelevancy. Relevant differences in optical performance in the sub-high-quality price categories can still be observed with roof prism-type binoculars today because well-executed technical problem mitigation measures and narrow manufacturing tolerances remain difficult and cost-intensive.

Independent focusing is an arrangement where the two telescope tubes are focused independently by adjusting each eyepiece. Binoculars designed for harsh environmental conditions and heavy field use, such as military or marine applications, traditionally have used independent focusing.

Central focusing

[23]

coated optics: one or more surfaces are anti-reflective coated with a single-layer coating.

fully coated: all air-to-glass surfaces are anti-reflective coated with a single-layer coating. Plastic lenses, however, if used, may not be coated.

[71]

multi-coated: one or more surfaces have anti-reflective multi-layer coatings.

fully multi-coated: all air-to-glass surfaces are anti-reflective multi-layer coated.

neck and shoulder straps for carrying

binocular harnesses (sometimes combined with an integrated field case) to distribute weight evenly for prolonged carrying

field carrying cases/side bags

binoculars storage/travel cases

rainguards for protecting the eyepieces outer lenses

(tethered) lens caps for protecting the objectives outer lenses

cleaning kits to carefully remove dirt from lenses and other surfaces

tripod adapters

Common accessories for binoculars are:

is the Distance to the object in meters.

is the known Object Height.

is the angular height of the object in number of Mil.

(UK) – sold binoculars commercially and primary supplier to the Royal Navy in WWII. The new range of Barr & Stroud binoculars are currently made in China (Nov. 2011) and distributed by Optical Vision Ltd.

Barr and Stroud

(US) – has not made binoculars since 1976, when they licensed their name to Bushnell, Inc., who made binoculars under the Bausch & Lomb name until the license expired, and was not renewed, in 2005.

Bausch & Lomb

(Belarus) – both porro prism and roof prism models manufactured.

BELOMO

(Germany)

Bresser

(US)

Bushnell Corporation

(Germany)– Premium binoculars[91]

Blaser

(Japan) – I.S. series: porro variants

Canon Inc

(US).

Celestron

(Germany) – Nobilem series: porro prisms

Docter Optics

(Japan) – FMTSX, FMTSX-2, MTSX series: porro

Fujinon

(Romania)

I.O.R.

(KOMZ) (Russia) – manufactures a variety of porro prism models, sold under the trade name Baigish

Kazan Optical-Mechanical Plant

(Japan)

Kowa

(Russia) – both porro prism and roof prism models, models with optical stabilizers. The factory is part of the Shvabe Holding Group

Krasnogorsky Zavod

(Germany) – Noctivid, Ultravid, Duovid, Geovid, Trinovid: most are roof prism, with a few high end porro prism examples

Leica Camera

(US)

Leupold & Stevens, Inc

(US) – Glacier (roof prism), TravelView (porro), CaptureView (folding roof prism) and Astro Series (roof prism). Also sells under the name Coronado.

Meade Instruments

(Czech Republic) – Meostar B1 (roof prism)

Meopta

(Germany)

Minox

(Japan) – EDG, High Grade, Monarch, RAII, and Spotter series: roof prism; Prostar, Superior E, E, and Action EX series: porro; Prostaff series, Aculon series

Nikon

(Japan)

Olympus Corporation

(Japan) – DCFED/SP/XP series: roof prism; UCF series: inverted porro; PCFV/WP/XCF series: porro

Pentax

(Germany) – both porro prism and roof prism models[92]

Sill Optics (Optolyth brand)

(in German) (Germany)[93]

Steiner-Optik

(UK) for birdwatching, sightseeing, hiking, camping

PRAKTICA

(Austria)[94]

Swarovski Optik

(Japan)

Takahashi Seisakusho

(US)

Tasco

(Japan) – Apex/Apex Pro: roof prism; Ultima: porro

Vixen (telescopes)

(US)

Vivitar

(US)

Vortex Optics

(Germany) – FL, Victory, Conquest: roof prism; 7×50 BGAT/T: porro, 15×60 BGA/T: porro, discontinued

Zeiss

There are many companies that manufacturer binoculars, both past and present. They include:

Anti-fog

Binoviewer

Globe effect

Lens

List of telescope types

Monocular

Optical telescope

Spotting scope

Tower viewer

Merlitz, Holger (2023). . Springer Cham. ISBN 978-3-031-44407-4.

The Binocular Handbook

Glossary of Optical Terms

Binocular Optics and Mechanics Chapter from Binocular Astronomy by Stephen Tonkin

Binocular Astronomy by Stephen Tonkin