Core Principles Governing Red Dot Sights

Chris G.

Red dot sights are invaluable assets to a shooter’s precision. These optics, marked by a straightforward red dot, have ushered in a new era in the sphere of shooting. They operate on basic principles that are an amalgamation of high-tech optics and a design that is easy to handle for users.

The following discussion will explore the detailed working of these devices, the variety available, and the multitude of benefits they confer. We will also explain how a spherical mirror and a light source work in tandem to create a reticle and highlight the differences between standard and miniature models. Lastly, we will underscore their advantages, such as quick target spotting and broad application.

What Are Red Dot Sights

Red dot sights, while often seen in the hands of military personnel or shooting sports enthusiasts, are fundamentally optics intended for short to moderate distances. This optic projects a simple reticle, typically a red or green dot, onto a spherical mirror using an LED light that illuminates specially coated, angled glass. The LED’s aperture hole dictates the size of the dot, measured in MOA.

Most red dot sights don’t come with built-in magnification. They’re highly versatile and can be adapted onto a variety of firearms from large rifles to smaller concealed carry pistols. With technology’s continual advancements, these sights have seen significant improvements in battery life, clarity, and overall quality. 

As one enthusiast puts it, “A red dot sight simplifies aiming and takes the guesswork out of the equation, making it a reliable partner in any shooting scenario.

How Does It Work

a diagram of how the red dot sight works

Understanding the functionality of a red dot sight involves understanding its core components: a spherical mirror and an LED light. The solid-state LED projects a beam of light onto the mirror which is coated with a partially silvered multilayer dielectric dichroic coating that only reflects red light. This reflected, collimated point of light forms the familiar red dot reticle that users see when peering through the sight.

The coated mirror allows other wavelengths of light through. Thus, the shooter can superimpose the reticle on the target while still being aware of the surroundings. The mirror is parallax-free, which means the red dot stays in position no matter the angle of the shooter’s eye in relation to the sight.

The dimension of the dot, denoted in MOA (Minutes Of Angle), is regulated by the aperture hole located in front of the LED. The size of the dot can alter the precision of the shot, with smaller dots offering a higher level of accuracy. This mechanism is both simple and effective, providing quick target detection without the need for perfect eye alignment.

Main Classifications of Red Dot Optics

different types of red dots sights

Red dot sights come in two main classifications, each tailored to specific firearms and shooting situations. Traditional rifle optics, the most common, are tube-structured and work best with larger-sized firearms. They usually have a 2 to 3 MOA red dot and a lens measuring 25mm or more.

Miniature red dots are becoming the go-to choice for concealed carry pistols. They can function as pistol sights or as a backup for rifle sights, like the FastFire 3. The size of the red dots, denoted in MOA, is determined by the aperture hole positioned ahead of the LED.

Why You Should Use a Red Dot

There are several compelling reasons why a red dot sight is a beneficial piece of shooting gear.

The main benefits stem from its simplicity, adaptability, and speedy target-locking ability. You simply need to “paint” your target with the red dot. With the right circumstances and constant training, you can easily hit that target with the bullet. Traditional iron sights, on the other hand, require aligning both the rear and front sights with the target. For beginners, this can be quite challenging. 

In dynamic situations, focusing using traditional iron sights can be time-consuming; a single second can be the difference between success and failure or even life or death. If you use red dots, however, you can substantially increase your shooting speed because you don’t have to sight through traditional sights. This improves efficiency and accuracy, especially under tense situations.

A red dot sight is user-friendly, eliminating unnecessary complications or adjustments. It’s adaptable, meaning it can be easily attached to a variety of firearms like rifles, handguns, or shotguns.


Red dot optics have certainly reshaped the field of firearm optics. Their straightforward use, swift target location, and adaptability have earned them a preference among experts and beginners. With various forms and dimensions to choose from, they meet a variety of shooting needs.

As advancements in technology persist, we can anticipate more precision and enhanced usability from red dot sights. These optical instruments continue to be valuable assets in contemporary shooting and tactical applications.

About the author

The name's Chris. Just a regular dude who loves firearms. I've been shooting since I was a kid. My old man taught me the ropes.

I'll never forget the first time I missed an easy shot on a buck, thanks to a bum scope. The image was fuzzier than my dog's butt. After that, I got obsessed with understanding scopes. What makes the good ones tick and the bad ones trash. After a few years and a few thousand bucks, I learned what separates the winners from the losers. Once I had a good stockpile of knowledge, I launched this site.

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