How Does A Red Dot Sight Work?

by | Dec 4, 2019

Have you ever thought about how exactly the red dot sight included in your firearm works? Have you ever looked into the interior to find out how it is manufactured? If you have done so, you are likely to know the basic information about a red dot sight. If you haven’t, here are some of the basic information about a red dot sight before getting onto the main part of this guide where we will be discussing about how a red dot sight works.

A red dot sight refers to an optical instrument which is used with firearm as a non-magnifying reflector sight. It is also used in other aiming and shooting equipments which offer users the ability to aim at a target. These equipments use red dot sight as a reticle which provides a target point for the user as an illuminated red dot. This is why it is named as a red dot sight.

A red dot sight features a light-emitting diode parallel to its optics for the generation of illuminated red dot reticle. The illuminated reticle is aligned without any parallax with the firearm used by the user. This doesn’t require you to place your eyes at certain position.

Why & Where Do We Need Red Dot Sight

A red dot sight can be beneficial for you in different cases. It is easy to use and can be used as fast acquisition for several aiming and shooting purposes like hunting, wars, target shooting, etc. With a red dot sight, you can just zero your firearm and aim the red dot at the exact same location where you want to shoot. Just with this simple task, you will be able to shoot at the target with very high accuracy which makes it one of the easiest gun sights to use.

Red dot sight is also significantly fast in comparison to its competitors. You will be able to aim at the target setting it aligned up with the red dot and shoot at it in a matter of just a second. With a red dot sight, you will also be able to look through the optical device with any angles. If you can see the red dot, but you aren’t sure about accurate alignment, you can just shoot at the target pointing with the red dot and your shot will hit the target quickly.

A red dot sight can also be used in any guns, firearms or aiming/shooting device to obtain the perfect alignment with the target and hit the target with high accuracy in super fast speed. The modern red dot sights feature very tiny red dots which you can still see and allow you to aim at the target with compact-sized firearms like handguns. It also lets you experience an accurate aiming mechanism, faster shot advantage along with long range of shots. In fact, a red dot sight can be highly beneficial for you in target shooting, military as well as archery and shooting competitions.


Major Reasons To Use A Red Dot Sight

Here are some of the major benefits of a red dot sight listed in the form of points:

  • A red dot sight is very easy to use.
  • The same red dot sight can be switched from one firearm to another and it will still offer the same outstanding features.
  • The LED-based red dots allow you to aim at the target with ultra high accuracy.
  • You will be able to aim and shoot at the target quickly in less than a second.
  • Due to its compact size, it can be placed on a firearm occupying less space so as to offer enough space for mounting other equipments such as night vision devices.
  • A red dot sight can be mounted on a firearm at any distance from your eyes without causing any focus issues.


Major Application Fields of Red Dot Sights

  • Hunting
  • Target Shooting
  • Aiming/Shooting Competitions
  • Archery
  • Military
  • Wars and Battlefields
  • Home Defense


How Does A Red Dot Sight Work

A red dot sight consists of light-emitting diodes of its axis focus at its main region. The LED can be found just against the mounting plate of the red dot sight. From these diodes, a spherical mirror included in the red dot sight results in the reflection of light. The light is reflected in the form of red colored dot.

External light-emitting mechanisms are easily avoided with this spherical mirror for the sight. Such mechanisms are tilted by the mirror and return back to the same position from where they arised. The special coating of angled spherical mirror in the LED makes it possible for the red light to be reflected and other light to pass through it.

The mirror creates a reticle with the reflection of red light after the LED shines a beam of light onto it. The created reticle is only visible through the optical instrument you are using and invisible from the other regions. There’s an aperture hole at the front part of the LED which controls the size of the reticle (red dot). The size is usually calculated in terms of MOA.

If the size of the red dot is large, you are likely to notice the dot easily and aim at the target quickly. Smaller red dots are also visible and are good to use while aiming at a shorter range. When you are thinking about shooting at larger distances, you are likely to see large portion of the target due to the smaller size of the dot making it easier for you to aim and shoot efficiently.


How Is It Different From Holographic Sight

A red dot sight is similar to a holographic sight since both of them are awesome examples of gun sights available out there. The major different between them is that the light-emitting diodes of red dot sight are replaced by laser diode in a holographic sight.

With a red dot sight, you just have the option to select a single red dot and aim at the target. In this case, a holographic sight can be more advantageous. Why? You can expect to use any reticle you want while using a holographic sight in your firearm.

However, with the addition of this special feature, you will also have to get additional materials for the reticle to be clearly visible while aiming. Since you require several materials for your reticle to be clear and easy to use, you will be forced to pay more charges which makes a holographic sight slightly expensive than the earlier one.


Working Mechanism

The working mechanism of a holographic sight is also different from the mechanism of a red dot sight that we discussed above. In a holographic sight, you won’t be able to see the image of your reticle when the system is turned off. You need to look through several lenses of your firearm even though it may look like a thin piece of single lens. The system is present in the middle lens where the image can be seen when it is turned on. The other lenses are generally made up of glass materials and they have nothing to do rather than supporting the middle lens.

The laser diode of the holographic sight reflects light through a mirror which later goes on against the reflecting glass which is aligned parallel to the light. The reflecting parallel glass is located just over the holographic sight behind the lenses. When the light is reflected, the diode will also make sure that it is reflected back in a straight line to focus the light. At the end, the reflected light will hit the holographic grating of the sight and the reticle can be clearly seen when the light finally passes through the lens. This makes the working mechanism of a holographic sight really complex, but still the reticle is not as clear as the red dot in a red dot sight.


Eye Relief and Exit Pupil

Eye relief refers to the distance from the scope necessary to obtain a clear image and the exit pupil is the size of the image which comes out of the shooting end of your firearm scope. For obtaining a clear image, the exit pupil needs to be slightly equal to your pupil size.

In a holographic sight, the perfect eye position for you to use the scope of your firearm will only be available when the exit pupil of your scope suits with the eye relief. However, a red dot sight doesn’t even feature a eye relies, which certainly means there’s no exit pupil as well.

A red dot sight is manufactured in such a way that you will be able to shoot with both eyes open since the position of the red dot is perfectly aligned with your target. Due to this outstanding feature, you will be able to mount your red dot sight at any position across the firearm’s barrel.

With a red dot sight, you will no longer have to place your body at a certain position as you have to do with a holographic sight. You can easily get clear image keeping your head in any position you want.



As mentioned in the working mechanism above, a holographic sight features several lenses along with laser diode for magnification. But, the case is totally opposite while looking at the red dot sight since it doesn’t feature multiple lens.

The magnification offered by a red dot sight is simple and makes it difficult for you to keep your shooting range at different distances. Along with this downside of the red dot sight, there’s an advantage; the red dot sight is lighter than the holographic sight. Even though the magnification in this sight is limited, you can use additional materials for being able to shoot at different ranges.


Tips for Buying a Red Dot Sight

Now that you have found out about the differences between a red dot sight and a holographic sight along with the working mechanism of both sights, you might have found out how a red dot sight can be dominant to the latter one. This will surely make you interested in buying a red dot sight. To help you purchase the best red dot sight, here are some tips that might be beneficial for you.


Type of Reticle

In a red dot sight, the reticle is always a red dot which you have to align with the aiming point. You can find red dot sights with different types of reticle. You need to select the one which really suits with your requirements.

Here are some tips to help you choose the perfect reticle in a red dot sight:

  • Size and Weight: The size and weight really matter while choosing a red dot sight with the best reticle. In fact, you need to choose the one which is compatible with your firearm. The size and weight also needs to be comfortable for you to use. The reason behind this is that you will have to face several storage issues if you choose the wrong size and the sight weight can change the way you will be holding your firearm.
  • Compatibility: Since red dot sights differ from each other in terms of their size and weight, the type of firearm becomes the major point to look for. You need to look for the red dot sight which is suitable to place on your firearm.


Housing Configuration

You can find red dot sights with two sorts of housing configurations. One is the tube style and the next one is the open style. The first one allows you to customize the lens of your sight, whereas the latter one doesn’t offer any customization options. The open style configuration offers just the general type of lens with no filters.



Red dot sights usually consume less power in comparison to other gun sights. This is why a general red dot sight lets you use it for thousands of hours. Along with that, a red dot sight also allows you to save the battery life by turning it off when you aren’t using it. You need to look for a red dot sight with better battery backup feature since every sight is likely to consume slightly more power in winter seasons.



Now that we have provided you the guide containing the entire working mechanism of a red dot sight along with its dominance over the working mechanism and other features of a holographic sight, it’s time for you to choose the best red dot sight. While choosing the best red dot sight, you must look for the one which is compatible with your firearm. Other features are optional, but you might also want to look for the one with a better battery backup feature to help you in cold weather.

If you have any confusion in mind regarding the working mechanism of a red dot sight, you can feel free to comment down mentioning your issue. You can also write down to us if you have any problems while selecting the best red dot sight for your firearm. We’ll try to help you right back away.

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