Sight (device)

"hot spot") 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,[citation needed] as well as augmented or even virtual reality-enabled digital cameras ("smart scopes") with software algorithms that produce digitally enhanced target images.

Sights such as this can be found on many types of devices including weapons, surveying and measuring instruments, and navigational tools.

[5] On many types of weapons they are built-in and may be fixed, adjustable, or marked for elevation, windage, target speed, etc.

Another type of optical sight is the reflector (or "reflex") sight, a generally non-magnifying optical device that allows the user to look through a partially reflecting glass element and see a reflection of an aiming point or some image (helping to aim on the target) superimposed on the field of view.

Over the years they became more sophisticated, adding lead computing gyroscopes and electronics (the World War II Gyro gunsight)[8] radar range finding and other flight information in the 1950s and 1960s, eventually becoming the modern head-up display.

A Royal Canadian Sea Cadet looks through a machine gun sight.
Picture through an aperture (or closed) iron sight on an H&K MP5 submachine gun
A view through a 20× power telescopic sight
Mark III free gun reflector sight mk 9 variant. The reticle image (golden circles) in this sight produced by an optical collimator is bounced off a beam splitter, and the image location is infinite, so parallax is removed. As a result, the reticle image remains on the target even though the viewer's head is moved side to side (the sight and the target is kept in alignment).
A circumferentor featuring a pair of slotted sights effectively constituting an alidade