How Does a Red Dot Sight work

How Does a Red Dot Sight work | Easy step

It’s the time when you have developed an interest in hunting. Or maybe you want to take part in a shooting competition for beginners. Whatever the reason be. Ultimately you have to begin by learning about red dot sights. They are essential devices for beginners and, in some cases, for professionals too.

What is a red dot sight?

It is a specially designed non-magnifying reflector sight. It is used in firearms and other aiming devices. Since they usually use an illuminated red dot as an aim point, hence they got the name of red dot sights. Some widgets have green or blue dots too. The colors may be different, but the basic mechanics are the same.

Difference from scope

Since they don’t possess a built-in system of magnification, they have 1× optics. So they differ from scopes for not having a magnification power.


It has many applications. Some of them are:

• It is best for beginners. Shooters who are learning to shoot can rely on red dot optics for improving their skills. It helps in learning how to target your aim. Nowadays, they are being used in all sizes and ranges of weapons. They can be as big as rifles or as small as handguns.

• Those who want to hunt. They help the hunters but not from exceptionally far-off distances.

• They are commonly used in speed shooting games.

• They are in common practice in paintball and airsoft games.

• Besides firearms and weapons, they are used in cameras, photography, and telescopes. They can easily capture images of fast-moving objects such as flying birds flying aircraft etc.

Types :

There is a vast range of options in it. You can use them for different purposes with slight differences in their manufacturing. They include;

⇒ According to weapons used.

➢ Rifle red dot sights; are long tubular weapon types. They usually have an MOA of 2-3, and the objective lens measures a minimum of 25mn. They target close to medium-range aims. You can enhance their working by mounting them with magnifiers and night vision optics.

➢ Tiny red dots for pistols and duty shotguns: they are ideal for use in short guns, pistols, and more sophisticated aiming in rifles.

⇒ According to working

➢ Prism sight: they use prisms and are very small.

➢ Reflex sights: this type is most common. They can be exposed or available variety used in short guns. The internal or closed combination has two mirrors and is usually found in rifles.

➢ Holographic sights: they have an image of the reticle between glass layers.

Working principles

For simple understanding, it is the reflection of light from a light source onto a spherical surface. This surface is specially used in a way that it only reflects red light. This enters the reticle and helps in the uneventful vision of the targets.

So at the collimation point, a red dot is illuminated because of the reflection from a red light-emitting diode. This red-lighted reticle stays in alignment with the weapon. This alignment is not affected by eye position. Hence it is parallax-free.

The spherical mirror that is used in this has special preparation. It has a partly silvered multi-layered coating. This coating is dielectric and dichroic. Resulting in reflecting only the red spectra, whereas all other light spectrums pass through. The LED has a visible wavelength of 670 nanometers seen as deep red color.

Measurement of red dot

They are measured in MOA (minutes of angle). The aperture hole monitors the MOA and is located in the farther end of the weapons. 1 MOA is equivalent to one inch at 100 yards.

  • Accuracy of the red dot optics related to red dot size.
  • The larger dot size helps to locate them quickly and hit the target better.
  • Smaller dots are better options at a moderate distance. In short, a smaller MOA covers fewer targets at a greater distance and vice versa.
  • As the length increases, locating and focusing the target becomes difficult.

Types of mounts used.

Several mounts are being used. Some of the best ones are mentioned below

• Nobles standard or Doctor: It has four notches and two screws. They are used in red dot sights such as Burris, Noblex sights, Vortex Viper, Fastfire, etc.

• Shield standard: It uses some additional dimensions to the ones used in the above entity. It is used in Shield red dot sights and Leupold delta point pro.

• There are some other varieties too.

Range of the red dot optics

It is used for near to moderate distance.


They have the following advantage

• They are simple to use. Their user-friendly manufacturing is the reason behind its popularity and wide range of applications.

• They are best for beginners.

• There speed

• They don’t have any magnification, so you don’t have to bother about eye relief or parallax.

• They use minimal powers so they can run for hundreds of hours. This is especially useful in extended military operations.

• They are convenient to use in dim or dark light. This helps in night operations. This is also helpful in situations of self-defense.


• Sometimes they are heavy to carry for long.

• Most of them are battery-powered and dependent. However, this is handled by using sights with long battery lives and by using LED. This LED consumes shallow power points and hence uses batteries for a long.

• Prism sights best aim when eyes are nearer to the scope. So at times, it becomes difficult to manage.

• Reflex sights are usually manufactured without magnification by default.

• Some of the red dot sights like holographic are expensive.


Red dot sights, especially with miniature sizes, are gaining popularity. Red dots work on simple optics rules without magnification. They are parallax-free. They have wide applications in fields using ammunition, photography of fast-moving objects, and a secondary finder scope in telescopes. You can use them with other mounts too.

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