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. [1] The hologram of the reticle is built into the window and is illuminated by a laser diode.
The first-generation holographic sight was introduced by EOTech—then an ERIM subsidiary—at the 1996 SHOT Show, [2] under the trade name HoloSight by Bushnell, with whom the company was partnered at the time, initially aiming for the civilian sport shooting and hunting market. It won the Optic of the Year Award from the Shooting Industry Academy of Excellence.[ citation needed ]
EOTech was the only company that manufactured holographic sights until early 2017, when Vortex introduced the Razor AMG UH-1 into the market as a competing product. [3]
Holographic weapon sights use a laser transmission hologram of a reticle image that is recorded in three-dimensional space onto holographic film at the time of manufacture. This image is part of the optical viewing window. The recorded hologram is illuminated by the collimated light of a laser diode built into the sight. The sight can be adjusted for range and windage by simply tilting or pivoting the holographic grating. [4] To compensate for any change in the laser wavelength due to temperature, the sight employs a holography grating that disperses the laser light by an equal amount but in the opposite direction as the hologram forming the aiming reticle.
The optical window in a holographic weapon sight looks like a piece of clear glass with an illuminated reticle in the middle. The aiming reticle can be an infinitely small dot whose perceived size is given by the acuity of the eye. For someone with 20/20 vision, it is about 1 minute of arc (0.3 mrad).[ citation needed ]
Holographic sights can be paired with "red dot magnifiers" to better engage farther targets.
Like the reflector sight, the holographic sight is not "parallax free", having an aim-point that can move with eye position. This can be compensated for by having a holographic image that is set at a finite distance with parallax due to eye movement being the size of the optical window at close range and diminishing to zero at the set distance, usually around the target range of 100 yards. [5]
Since the reticle is a transmission hologram, illuminated by a laser shining through hologram presenting a reconstructed image, there is no need for the sight "window" to be partially blocked by a semi-silvered or dielectric dichroic coating needed to reflect an image such as in standard reflex sights. [2] Holographic sights therefore have the potential for better light transmission than reflector sights.
Holographic sights are considerably more expensive than red dot sights, due to their complexity as well as there being only two manufacturers of holographic sights.
Holographic sights are generally bulkier than reflex sights and require a rifle to mount, while red dot sights have been made small enough to fit handguns. [6]
Holographic sights have shorter battery life when compared to reflex sights that use LEDs, such as red dot sights. The laser diode in a holographic sight uses more power and has more complex driving electronics than a standard LED of an equivalent brightness, reducing the amount of time a holographic sight can run on a single set of batteries compared to a red dot sight, [7] around 600 hours for typical holographic sights, compared to sometimes up to tens of thousands of hours for red dot sights. [8] For example, the Vortex Razor AMG UH-1 holographic sight has been quoted as having an expected battery life of 1,000 to 1,500 hours (1½ to 2 months) on medium setting. [9] The Aimpoint CompM5s red dot sight has an expected battery life of around 8,000 to 50000 hours (1 to 5 years) depending on the setting. [8]
Holography is a technique that enables a wavefront to be recorded and later reconstructed. It is best known as a method of generating three-dimensional images, and has a wide range of other uses, including data storage, microscopy, and interferometry. In principle, it is possible to make a hologram for any type of wave.
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.
The CompM2 is a battery-powered, non-magnifying red dot type of reflex sight for firearms manufactured by Aimpoint AB. It was first introduced in the U.S. Armed Forces in 2000, designated as the M68 Close Combat Optic. It is also known as the M68 Aimpoint and is designed to meet United States military standards. The sight is designed for use with the M16/M4 family of rifles, but can be mounted on any weapon fitted with an upper Picatinny rail. It is also NVG-compatible—the aiming dot is still visible through night vision scopes and goggles. The Army's M68 designation was also applied to a later version of the sight, the Aimpoint CompM4.
Raytheon ELCAN Optical Technologies, also simply ELCAN, is a Canadian optics and electronics manufacturing company owned by American defense contractor RTX Corporation, currently based in Midland, Ontario. ELCAN produces optical devices geared towards both civilian and military markets, and their products are sold through Armament Technology Inc. based in Halifax, Nova Scotia, and associated channels of dealers.
A sight or sighting device is any device used to assist in precise visual alignment of ranged weapons, surveying instruments, aircraft equipment or optical illumination equipments 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.
Aimpoint AB is a Swedish optics company based in Malmö, Sweden that manufactures red dot sights.
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.
EOTECH is an American company that designs, manufactures, and markets electro-optic and night vision products and systems. The company is headquartered in Plymouth, Michigan. They produce holographic weapon sights for small arms that have been adopted by various military and law enforcement agencies as close quarters battle firearm sights.
The Special Operations Peculiar MODification (SOPMOD) kit is an accessory system for the M4A1 carbine, CQBR, FN SCAR Mk 16/17, HK416 and other weapons used by United States Special Operations Command (USSOCOM) special forces units, though it is not specific to SOCOM. The kit allows US Special Operations Forces personnel to configure their weapons to individual preferences and customize for different mission requirements.
The Aimpoint CompM4 is a non-magnified red dot style gun sight adopted by the U.S. Armed Forces, designated the M68 CCO. It is produced by the Swedish company Aimpoint and is the successor to the earlier M68CCO, the Aimpoint CompM2.
Volume holograms are holograms where the thickness of the recording material is much larger than the light wavelength used for recording. In this case diffraction of light from the hologram is possible only as Bragg diffraction, i.e., the light has to have the right wavelength (color) and the wave must have the right shape. Volume holograms are also called thick holograms or Bragg holograms.
Vortex Optics is an American manufacturer of special optical equipments for hunting, wildlife watching, outdoor recreation, shooting sports and law enforcement and military. Vortex products include binoculars, spotting scopes, riflescopes, reflex sights, holographic sights and other accessories. It once had a sister company known as Eagle Optics, which developed high quality optics for birdwatchers.
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 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. They are also referred to as collimating sights or "occluded eye gunsight" (OEG).
Scope mounts are rigid implements used to attach (typically) a telescopic sight or other types of optical sights onto a firearm. The mount can be made integral to the scope body or, more commonly, an external fitting that clamp onto the scope tube via screw-tightened rings. The scope and mount are then fastened onto compatible interfaces on the weapon. Words such as mounts and bases are used somewhat loosely, and can refer to several different parts which are either used together or in place of each other as ways to mount optical sights to firearms.
A sight magnifier is an optical telescope that can be paired with a non-magnifying optical sight on a weapon to create a telescopic sight. They work with the parallel collimated reticle image produced by red dot sights and holographic weapon sights. They may synonymously be referred to as a red dot magnifier, reflex sight magnifier, holographic sight magnifier, or flip to side magnifiers.
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.