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Holographic Weapon Sight
A holographic weapon sight or holographic diffraction sight is a non-magnification, 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. History The first-generation holographic sight was introduced by EOTech—then an Environmental Research Institute of Michigan, ERIM subsidiary—at the 1996 SHOT Show,Jane's international defence review: IDR.: Volume 34, page 76 under the trade name HoloSight by Bushnell Corporation, 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. EOTech was the only company that manufactured holographic sights until early 2017, when Vortex Optics, Vortex introduced the Razor AMG UH-1 into the market ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EOTech 512 Reticle
EOTECH is an American company that designs, manufactures, and markets Electro-optics, electro-optic and Night-vision device, night vision products and systems. The company is headquartered in Plymouth, Michigan, 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. They also have roots in the Environmental Research Institute of Michigan (ERIM), a not-for-profit R&D institute. Of the many inventions by ERIM researchers, some were in the fields of Synthetic-aperture radar, synthetic aperture radar, laser holography, and aircraft head-up displays. Products and services EOTECH manufactures holographic weapon sights, sight magnifier, magnified optics, and night vision sensors. EOTECH was the first company to create holographic sights, having solved the problem of wavelength instability exhibited by laser diodes. They introduced their first-generat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 aiming point or some image (helping to aim the device, to which the sight is attached, on the target) superimposed on the field of view. These sights work on the simple optical principle that anything (such as an illuminated reticle) 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 image is at infinity, it stays in alignment with the device to which the sight is attached regardless of the viewer's eye position to the sight, removing most of the parallax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichroic Filter
In optics, a dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths (colours) (not to be confused with dispersion), or one in which light rays having different polarizations are absorbed by different amounts. In beam splitters The original meaning of ''dichroic'', from the Greek ''dikhroos'', two-coloured, refers to any optical device which can split a beam of light into two beams with differing wavelengths. Such devices include mirrors and filters, usually treated with optical coatings, which are designed to reflect light over a certain range of wavelengths and transmit light which is outside that range. An example is the dichroic prism, used in some camcorders, which uses several coatings to split light into red, green and blue components for recording on separate CCD arrays, however it is now more common to have a Bayer filter to filter individual pixels on a single CCD array. This kind of dichroic device doe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silvered
Silvering is the chemical process of coating a non-conductive substrate such as glass with a reflective substance, to produce a mirror. While the metal is often silver, the term is used for the application of any reflective metal. Process Most common household mirrors are "back-silvered" or "second-surface", meaning that the light reaches the reflective layer after passing through the glass. A protective layer of paint is usually applied to protect the back side of the reflective surface . This arrangement protects the fragile reflective layer from corrosion, scratches, and other damage. However, the glass layer may absorb some of the light and cause distortions and optical aberrations due to refraction at the front surface, and multiple additional reflections on it, giving rise to "ghost images" (although some optical mirrors such as Mangins take advantage of it). Therefore, precision optical mirrors normally are "front-silvered" or " first-surface", meaning that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphical), foreshortening, nearby objects show a larger parallax than farther objects, so parallax can be used to determine distances. To measure large distances, such as the distance of a planet or a star from Earth, astronomers use the principle of parallax. Here, the term ''Stellar parallax, parallax'' is the semi-angle of inclination between two sight-lines to the star, as observed when Earth is on opposite sides of the Sun in its orbit. These distances form the lowest rung of what is called "the cosmic distance ladder", the first in a succession of methods by which astronomers determine the distances to celestial objects, serving as a basis for other distance measurements in astronomy forming the higher rungs of the ladder. Because parallax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector 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 aiming point or some image (helping to aim the device, to which the sight is attached, on the target) superimposed on the field of view. These sights work on the simple optical principle that anything (such as an illuminated reticle) 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 image is at infinity, it stays in alignment with the device to which the sight is attached regardless of the viewer's eye position to the sight, removing most of the parallax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Dot Magnifier
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. Description Sight magnifiers are optical telescopes that provide increased magnification to a shooter's view when they are engaged. They are commonly mounted behind red dot and holographic sights that produce a collimated reticle image. Most have mounts which allow them to flip to the side when not in use, though immobile mounts exist as well. This allows the user to switch between a non-magnified image and a telescopic magnified view for more distant targets. Magnifiers typically are 3× telescopes but can range from 2–6× or more. They are used by police and special operations forces who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milliradian
A milliradian (International System of Units, SI-symbol mrad, sometimes also abbreviated mil) is an SI derived unit for angular measurement which is defined as a thousandth of a radian (0.001 radian). Milliradians are used in adjustment of firearm sights by adjusting the angle of the sight compared to the barrel (up, down, left, or right). Milliradians are also used for comparing shot groupings, or to compare the difficulty of hitting different sized shooting targets at different distances. When using a scope with both mrad adjustment and a reticle with mrad markings (called an "mrad/mrad scope"), the shooter can use the reticle as a ruler to count the number of mrads a shot was off-target, which directly translates to the sight adjustment needed to hit the target with a follow-up shot. Optics with mrad markings in the reticle can also be used to make a stadiametric rangefinding, range estimation of a known size target, or vice versa, to determine a target size if the distan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minute Of Arc
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (abbreviated as arcsec), or arc second, denoted by the symbol , is a unit of angular measurement equal to of a minute of arc, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal (base 60) subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
20/20 Vision
Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye influence the sharpness of an image on its retina. Neural factors include the health and functioning of the retina, of the neural pathways to the brain, and of the interpretative faculty of the brain. The most commonly referred-to visual acuity is ''distance acuity'' or ''far acuity'' (e.g., "20/20 vision"), which describes someone's ability to recognize small details at a far distance. This ability is compromised in people with myopia, also known as short-sightedness or near-sightedness. Another visual acuity is '' near acuity'', which describes someone's ability to recognize small details at a near distance. This ability is compromised in people with hyperopia, also known as long-sightedness or far-sightedness. A common optical cause of low visual acui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windage
In aerodynamics, firearms ballistics, and automobiles, windage is the effects of some fluid, usually air (e.g., wind) and sometimes liquids, such as oil. Aerodynamics Windage is a force created on an object by friction when there is relative movement between air and the object. Windage loss is the reduction in efficiency due to windage forces. For example, electric motors are affected by friction between the rotor and air. Large alternators have significant losses due to windage. To reduce losses, hydrogen gas may be used, since it is less dense. Causes of windage are: * The object is moving and being slowed by resistance from the air. * A wind is blowing, producing a force on the object. The term can refer to: * The effect of the force, for example the deflection of a missile or an aircraft by a cross wind. * The area and shape of the object that make it susceptible to friction, for example those parts of a boat that are exposed to the wind. Aerodynamic streamlining can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
