How many categories of optical sights ?

Sights are mainly divided into the following three categories: telescope sight, collimating optical sight and reflex sight

The origin of sight, or optical sight, has been difficult to verify. It is said that at least in Europe in the 16th century, someone had tried to fix glasses on the butt of the gun. It is recorded that before the 19th century, there had been telescopic aiming devices on firearms, which could be used for aiming under low light conditions. Sight can be divided into holographic sight, internal red and green dot sight and laser sight.

In the 1840s, some American gunsmiths began to manufacture guns with optical aiming devices. In 1848, Morgan James of New York State designed a tubular aiming device with the same length as the gun barrel. The rear part of the device was installed with a glass lens, and there were two crosshairs for aiming. Later, similar sighting devices were used in the American Civil War. However, the sight with real practical value was born in 1904, developed by Carl Zeiss of Germany, and used in the First World War. In the Second World War, the sight began to mature.

Sights are mainly divided into the following three categories: telescope sight, collimating optical sight and reflex sight. Among them, telescopic sight and reflective sight are the most popular. The above two types of collimators are mainly used in the daytime, so they are also collectively referred to as the day scope/sight. In addition, there is a night scope/sight for night aiming, which adds night vision devices to the above two types of collimators. According to the types of night vision devices, they can be divided into low light collimators and infrared collimators (which can be subdivided into active infrared and thermal imaging).