FACTOID # 65: In the 1990's, nearly half of all arms exported to developing countries came from the United States of America.
 
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A drawing of different reticles used in telescopic sights. A) fine crosshair B) duplex crosshair C) German reticle D) target dot E) mil-dot F) circle (used for shotguns) G) old rangefinding H) modern rangefinding I) Dragunov type
A drawing of different reticles used in telescopic sights. A) fine crosshair B) duplex crosshair C) German reticle D) target dot E) mil-dot F) circle (used for shotguns) G) old rangefinding H) modern rangefinding I) Dragunov type

A crosshair or reticle is a shape superimposed on an image that is used for precise alignment of a device. Crosshairs are most commonly a "+" shape, though many variations exist, including dots, posts, circles, and chevrons. Most commonly associated with telescopic sights for aiming firearms, crosshairs are also common in optical instruments used for astronomy and surveying, and are also popular in graphical user interfaces as a precision pointer. The crosshair was invented by Robert Hooke, and dates to the 17th century. Image File history File links Reticles. ... Image File history File links Reticles. ... An Ethiopian soldier practices with a Romanian PSL sniper rifle as part of a joint exercise with American troops. ... This page is about the pattern or symbol called a chevron. ... View through a 4x rifle scope A telescopic sight, commonly referred to as a scope, is a device used to give an accurate point of aim for a firearm. ... An assortment of modern handheld firearms using fixed ammunition, including military assault rifles, a sporting shotgun (fourth from bottom), and a tactical shotgun (third from bottom). ... This article or section needs a complete rewrite for the reasons listed on the talk page. ... It has been suggested that Software pointer be merged into this article or section. ... A portrait, claimed by historian Lisa Jardine to be of Robert Hooke. ... (16th century - 17th century - 18th century - more centuries) As a means of recording the passage of time, the 17th century was that century which lasted from 1601-1700. ...

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Use in firearms

Telescopic sights for firearms, generally just called scopes, are probalby the device most often associated with crosshairs. Motion pictures and the media often use a view through crosshairs as a dramatic device, which has given crosshairs wide cultural exposure. For other uses see film (disambiguation) Film refers to the celluliod media on which movies are printed Film — also called movies, the cinema, the silver screen, moving pictures, photoplays, picture shows, flicks, or motion pictures, — is a field that encompasses motion pictures as an art form or as part of...


Reticle shape

While the traditional thin crossing lines are the the original and still the most familiar crosshair shape, they are really best suited for precision aiming at high contrast targets, as the thin lines are easily lost in complex backgrouns, such as those encountered while hunting. Thicker bars are much easier to discern against a complex background, but lack the precision of thin bars. The most popular types of crosshair in modern scopes are variants on the duplex crosshair, with bars that are thick on the perimiter and thin out in the middle. The thick bars allow the eye to quickly locate the center of the reticle, and the thin lines in the center allow for precision aiming.


Wire crosshairs

The original crosshairs in fact used hair, as it was thin and strong. Many modern scopes use wire crosshairs, which can be flattened to various degrees to change the width. These wires are usually silver in color, but appear black when backlit by the image passing through the scope's optics. Wire reticles are by nature fairly simple, as they require lines that pass all the way across the reticle, and the shapes are limited to the variations in thickness allowed by flatting the wire; duplex crosshairs, and crosshairs with dots are possible, and multiple horizontal or veritcal lines may be used. The advantage of wire crosshairs is that they are fairly tough and durable, and provide no obstruction to light passing through the scope.


Etched reticles

Many modern crosshairs are actually etched onto a thin plate of glass, which allows a far greater latitude in shapes. Etched glass reticles can have floating elements, which do not cross the reticle; circles and dots are common, and some types of glass reticles have complex sections designed for use in range estimation and bullet drop and drift compensation (see external ballistics). The disadvantage of glass reticles is that they are less durable than wire crosshairs, and the surface of the glass reflects some light, lessening transmission through the scope. Etching is an intaglio method of printmaking in which the image is incised into the surface of a metal plate using an acid. ... Glass can be made transparent and flat, or into other shapes and colours as shown in this ball from the Verrerie of Brehat in Brittany. ... External ballistics is the part of ballistics tht refers to the behavior of a bullet after it exits the barrel and before it hits the target. ...


Illuminated reticles

Either type of reticle can be illuminated for use in low light. Illumination is usually provided by a battery powered LED, though other sources can be used. The light is projected forward through the scope, and reflects off the back surface of the reticle. Red is the most common color used, as it is the least destructive to the shooter's night vision. The word battery has a number of senses, most of which are discussed in articles cited below. ... External links LEd Category: TeX ... Night-vision is seeing in the dark. ...


Focal plane

The reticle may be located at the front or rear focal plane of the scope. On fixed power scopes, there is no significant different, but on variable power scopes the front plane reticle remains at a constant size compared to the target, while rear plane reticles remain a constant size to the user, as the target image grows and shrinks. Front plane reticles are slightly more durable, but most users prefer that the reticle remain constant as the image changes size, so nearly all modern variable power scopes are rear focal plane designs.


Collomated reticles

Red dot sights use a significantly different method of operation than normal telescopic sights. The red dot sights rarely provide any magnification, but are instead designed for the widest practical field of view, and high speed aiming. The red dot sight uses a partially reflecting concave surface that acts as a reflective but not a refractive lens. The image of the target passes through relatively undistorted, while the back surface reflects a collimated image of the reticle back to the user. As the name implies, the most common reticle is a simple red dot, but other colors and shapes are possible by passing the light through an etched glass reticle. Some models even have a dial containing multiple reticles etched at different point, allowing the user to change the shape of the reticle by rotating the dial. The red dot sight, infinity sight or reflex sight is an optical firearm sight, sometimes also used as an aiming sight for telescopes. ...


Holographic reticles

Bushnell has recently introduced the Holosight, which is similar to a red dot sight, but using a holographic reticle and a laser diode for illumination. The Holosight is able to render a 3-D reticle image. The downside to the Holosight is the cost and weight; it is more expensive and significantly heavier than most red dot sights, which are it's nearest competition. Bushnell may refer to: Bushnell, Florida Bushnell, South Dakota Bushnell, Nebraska Bushnell, Illinois This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... This article is about the photographic technique. ... A packaged laser diode with penny for scale. ... 2-dimensional renderings (ie. ...


  Results from FactBites:
 
Crosshair Exploration & Mining Corp. - Home Page - Tue Jun 19, 2007 (264 words)
Crosshair is a leading junior exploration company focused on exploring and developing uranium in the Central Mineral Belt of Labrador.
Crosshair is also demonstrating the multi-deposit potential of the project by successfully developing and drilling several new uranium targets on the 750 square kilometer project.
Crosshair also continues to advance its gold and Volcanic Hosted Massive Sulphide (VHMS) projects in Newfoundland, which are slated for a dividend spin-out to shareholders in 2008.
Crosshair - Wikipedia, the free encyclopedia (876 words)
A crosshair or reticle is a shape superimposed on an image that is used for precise alignment of a device.
Most commonly associated with telescopic sights for aiming firearms, crosshairs are also common in optical instruments used for astronomy and surveying, and are also popular in graphical user interfaces as a precision pointer.
The crosshair was invented by Robert Hooke, and dates to the 17th century.
  More results at FactBites »

 

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