A collimator sight is a type of

optical sight A sight is an aiming device used to assist in visually aligning ranged weapons, surveying instruments or optical illumination equipments with the intended target. Sights can be a simple set or system of physical markers that have to be aligne ...

that allows the user looking into it to see an illuminated aiming point aligned with the device the sight is attached to, regardless of eye position (with little

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

). They are also referred to as collimating sights or "occluded eye gunsight" (OEG).

Description

The basic layout of a collimator sight is a closed tube with a lens at its open end and a luminous

reticle A reticle, or reticule also known as a graticule, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the screen of an oscilloscope, ...

mounted near the closed end at the focus of the lens, creating an optical collimator. The reticle is illuminated by an electronic light source (an

incandescent light bulb An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...

or, more recently, a

light-emitting diode A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...

) or by ambient light gathered behind the reticle via an

opalescent Opalescence refers to the optical phenomena displayed by the mineraloid gemstone opalopalescent. 2019. In Noah Webster's 1828 American Dictionary of the English Language. Retrieved January 7, 2019, from https://1828.mshaffer.com/d/word/opale ...

window or

fiber optic An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to ...

light pipe Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...

. Collimator sights are a relatively old idea, being used in many forms for almost 100 years.

Usage

These sights are 'blind' sights; that is, they are used with both eyes open while one looks into the sight, with one eye open and moving the head to alternately see the sight and then at the target, or using one eye to partially see the sight and target at the same time.

Applications

Collimator sights as weapon sights are considered to be very simple, rugged and low cost devices. They have been used on mortars and

field gun A field gun is a field artillery piece. Originally the term referred to smaller guns that could accompany a field army on the march, that when in combat could be moved about the battlefield in response to changing circumstances ( field artille ...

s since

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. There have had more modern incarnations such as the Armson ''Occluded Eye Gunsight'' (OEG) and the Normark Corp. ''Singlepoint''. These both used a light gathering rod in a protective clear dome collecting ambient light to illuminate a 'dot' style

. Collimator sights have had uses as a small arms sight for low light situations (such as twilight or "room clearing" operations) since there is no intervening optical window that can block the light, allowing the use of both eyes with a relatively un-obstructed field of view.Maj. Michael J. Stroff III, USMCR, Night Marksmanship: A Step Forward, Marine Corps Gazette; vol 74 no 4; Apr 1990; pp. 44-45 illus In recent years the introduction of illuminated

reflex sight A reflector sight or reflex sight is an optical sight that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These sigh ...

holographic sight A holographic weapon sight or holographic diffraction sight is a non- magnifying gunsight that allows the user to look through a glass optical window and see a holographic reticle image superimposed at a distance on the field of view. The hologram ...

s, and even

telescopic sight A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate po ...

s; (for example the

Advanced Combat Optical Gunsight The Advanced Combat Optical Gunsight (ACOG) is a series of prismatic telescopic sights manufactured by Trijicon. The ACOG was originally designed to be used on the M16 rifle and M4 carbine, but Trijicon has also developed ACOG accessories for ot ...

(ACOG) using the " Bindon Aiming Concept") have replaced dedicated collimator sights since these other types of sights can be used with both eyes in the role of a collimator sight. Collimator sights are also used in astronomy as

Finderscope A finderscope is an accessory sighting device used in astronomy and stargazing, typically a small auxiliary refracting telescope/monocular mounted parallelly on a larger astronomical telescope along the same line of sight. The finderscope usuall ...

s to aim a telescope at a designated celestial object.

References

{{Reflist Firearm sights Optical devices

Description

Usage

Applications

See also

References