A collimator sight is a type of optical sight 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). [1] They are also referred to as collimating sights [2] or "occluded eye gunsight" (OEG). [3]
The basic layout of a collimator sight is a closed tube with a lens at its open end and a luminous reticle 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 or, more recently, a light-emitting diode) or by ambient light gathered behind the reticle via an opalescent window or fiber optic light pipe. Collimator sights are a relatively old idea, [4] being used in many forms for almost 100 years. [5]
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. [6]
Collimator sights as weapon sights are considered to be very simple, rugged and low cost devices. [7] They have been used on mortars and field guns since World War I. There have had more modern incarnations such as the Armson Occluded Eye Gunsight (OEG) and the Normark Corp. Singlepoint. [8] [9] These both used a light gathering rod in a protective clear dome collecting ambient light to illuminate a 'dot' style reticle.
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. [10] In recent years the introduction of illuminated reflex sights, holographic sights, and even telescopic sights; (for example the Advanced Combat Optical Gunsight (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 Finderscopes to aim a telescope at a designated celestial object.
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 half-angle of inclination between those two lines. Due to foreshortening, nearby objects show a larger parallax than farther objects, so parallax can be used to determine distances.
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 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.
A head-up display, or heads-up display, also known as a HUD or head-up guidance system (HGS), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view information with the head positioned "up" and looking forward, instead of angled down looking at lower instruments. A HUD also has the advantage that the pilot's eyes do not need to refocus to view the outside after looking at the optically nearer instruments.
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 other firearms. Models provide fixed-power magnification levels from 1.25× to 6×. ACOG reticles are illuminated at night by an internal tritium phosphor. Some versions have an additional daytime reticle illumination via a passive external fiberoptic light pipe or are LED-illuminated using a dry battery. The first ACOG model, known as the TA01, was released in 1987.
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, to provide measurement references during visual inspections. Today, engraved lines or embedded fibers may be replaced by a digital image superimposed on a screen or eyepiece. Both terms may be used to describe any set of patterns used for aiding visual measurements and calibrations, but in modern use reticle is most commonly used for weapon sights, while graticule is more widely used for non-weapon measuring instruments such as oscilloscope display, astronomic telescopes, microscopes and slides, surveying instruments and other similar devices.
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 position in its optical system to provide an accurate point of aim. Telescopic sights are used with all types of systems that require magnification in addition to reliable visual aiming, as opposed to non-magnifying iron sights, reflector (reflex) sights, holographic sights or laser sights, and are most commonly found on long-barrel firearms, particularly rifles, usually via a scope mount. Similar devices are also found on other platforms such as artillery, tanks and even aircraft. The optical components may be combined with optoelectronics to add night vision or smart device features.
A collimator is a device which narrows a beam of particles or waves. To narrow can mean either to cause the directions of motion to become more aligned in a specific direction, or to cause the spatial cross section of the beam to become smaller.
The Sight Unit Small Arms, Trilux, or SUSAT, is a 4× telescopic sight, with tritium-powered illumination utilised at dusk or dawn. The full name of the current model is the SUSAT L9A1. The sight is not designed as a sniper sight, but is rather intended to be mounted on a variety of rifles and to be used by all infantrymen. A similar device is the Advanced Combat Optical Gunsight (ACOG).
A sight or sighting device is any device used to assist in precise visual alignment of weapons, surveying instruments, aircraft equipment, optical illumination equipment or larger optical instruments with the intended target. Sights can be a simple set or system of physical markers that serve as visual references for directly aligning the user's line of sight with the target, or optical instruments that provide an optically enhanced—often magnified—target image aligned in the same focus with an aiming point. There are also sights that actively project an illuminated point of aim onto the target itself so it can be observed by anyone with a direct view, such as laser sights and infrared illuminators on some night vision devices, as well as augmented or even virtual reality-enabled digital cameras with software algorithms that produce digitally enhanced target images.
Boresighting is a method of visually pre-aligning a firearm barrel's bore axis with the target, in order to more easily zero the gunsight. The process is usually performed on a rifle, and can be accomplished either with the naked eye, or with a specialized device called a boresighter.
Aimpoint AB is a Swedish optics company based in Malmö, Sweden that manufactures red dot sights.
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 usually has a much smaller magnification than the main telescope, thus providing a larger field of view, useful for manually pointing the main telescope into a roughly correct direction that can easily place a desired astronomical object in view when zooming in. Some finderscopes have sophisticated reticles to more accurately aim the main telescope and/or even perform stadiametric measurements.
Trijicon, Inc. is an American manufacturing company based in Wixom, Michigan, that designs and distributes sighting devices for firearms including pistols, rifles and shotguns. Trijicon specializes in self-luminous optics and night sights, mainly using the low-energy tritium illumination, light-gathering fiber optics and battery-powered LED.
The C79 optical sight (SpecterOS3.4x) is a telescopic sight manufactured by Elcan. A variant, the M145 Machine Gun Optic is in use by the US military. It is 3.4×28, meaning 3.4x magnification, and a 28mm diameter objective lens. A tritium illuminated reticle provides for normal and low-light conditions sighting. It can be mounted to a variety of rifles and light machine guns using the Picatinny rail mounting system or the similar Diemaco rail system found on small arms produced by Diemaco/Colt Canada. Similar rifle sights are the Sight Unit Small Arms, Trilux (SUSAT) and the Advanced Combat Optical Gunsight (ACOG).
The PSO-1 is a 4×24 telescopic sight manufactured in Russia by the Novosibirsk instrument-making factory and issued with the Russian military Dragunov sniper rifle. It was introduced on 3 July 1963 together with the Dragunov sniper rifle.
A red dot sight is a common classification for a non-magnifying reflector sight that provides an illuminated red dot to the user as a point of aim. A standard design uses a red light-emitting diode (LED) at the focus of collimating optics, which generates a dot-style illuminated reticle that stays in alignment with the firearm the sight is attached to, regardless of eye position.
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 sights work on the simple optical principle that anything at the focus of a lens or curved mirror will appear to be sitting in front of the viewer at infinity. Reflector sights employ some form of "reflector" to allow the viewer to see the infinity image and the field of view at the same time, either by bouncing the image created by lens off a slanted glass plate, or by using a mostly clear curved glass reflector that images the reticle while the viewer looks through the reflector. Since the reticle is at infinity it stays in alignment with the device to which the sight is attached regardless of the viewer's eye position, removing most of the parallax and other sighting errors found in simple sighting devices.
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 of the reticle is built into the window and is illuminated by a laser diode.
1P78 is a telescopic sight manufactured by Novosibirsk Instrument-Making Plant and in use with the Russian Armed Forces, intended as a replacement for the older PSO-1 and 1P29 scopes currently being used by the Russian military. The optic is intended to become the standard issue sight for the infantry riflemen within the Russian military.
A prism sight or prismatic sight, sometimes also called prism scope or prismatic scope, is a type of telescopic sight which uses a reflective prism for its image-erecting system, instead of the series of relay lenses found in traditional telescopic sights. The use of prisms makes it possible to construct a shorter and lighter sight, or with an offset between the eyepiece and objective axes.