How Does a Scope Work? Know the Secret from Expert Hunters

how does a scope work
Written by Erik Himmel

Major Parts of a Rifle Scope

Riflescopes are devices that are built with a couple of lenses used specifically for magnification. It’s a type of reticle that helps aim where the bullet will impact. You can compare this to the function of a telescope and the overlaid crosshair attached to it.

There is a vast variety of scopes such as Thermal Scopes, Rimfire Scopes, Hunting Scopes, Long Range Scopes, and they are all designed in different styles, configurations, sizes, price points, and constructions. In this article, we will be looking at the basics operation of a riflescope.

Simmons 8-Point 3-9x50mm Rifle Scope with Truplex Reticle
  • Riflescope offers robust feature set for the price; Coated optics provide bright, high contrast images; Fully coated optics, waterproof, fog proof & recoil proof
  • 1/4 MOA sure grip audible click windage and elevation adjustments
  • Proprietary true zero windage and elevation adjustment system stays locked to 0 through strenuous conditions; QTA eyepiece enables easy target acquisition
  • 3 9X magnification and 50 millimeter objective lens; 31.4 foot field of view at 100 yards at 3X and 10.5 foot field of view at 100 yards at 9X
  • 3.75 inch eye relief, 16.6 to 5.6 millimeter exit pupil, 13.2 ounce weight, and 60 inch adjustment range at 100 yards

How Does a Scope Work?

The lens is one of the most important aspects of a riflescope: the erector, objective, ocular, and magnifying lenses. The objective is placed in front of the user. The primary function of the lens is to transmit light directly to the lens of the erector that is known to flip all created images and then send it directly to the magnifying lens. The magnifying lens help to generate more magnification on an image. From that point, light is transmitted straight to the ocular lens for proper viewing. Objective bell is used to protect the objective lens. The magnifying lens, and the erector lens are all housed within the riflescope tube.

how does a scope work

How Does Scope Magnification Work?

The riflescope has a similar mode of operation with the old telescope you once used as a child. Lightwave travel passes the objective lens and gets down to a point known as the focal point inside the riflescope. At this point, the image gets inverted and then captured with the lens of the erector, which is known as the “picture reversal.”  The scope flips the image and send it to the proper orientation, and then transfer light to the lens known for magnification.

At this point, the magnifying lens will adjust a bit forward in the direction of each objective lens. At the same time, it increases the magnification of the image, and when the magnification is reduced, the lens moves backward in the direction of the ocular lens. The light that gets into the scope is collected at the other part of the rifle to present an image on the lens.

The eye relief on the scope explains the distance that exists between the eyepiece and eye of the shooter, where they can view the field.  If the eye relief is shot, then the scope will be placed further in the direction of the stock and a bit closer to the face of the user. On the other hand, if you have a long relief scope similar to that of a scout rifle, you will need to create enough space between your eye and the eyepiece.

The use of O rings is a major strategy used by most manufacturers to create a waterproof riflescope. The scope is sealed to help prevent dust and moisture from getting into the tube. Waterproofing the scope is not good enough to prevent fogging or condensation on the surface of the lenses; this can most time occur when there is a change in the range of temperature from one extreme point to another.  That is from freezing, snowy temperature to warm weather.

Due to the change of temperature, which can most time lead to the formation of fog on the surface of the lens, most manufacturers use gases like argon, nitrogen, or different forms of chemical combination that can absorb moisture. Since the lenses cannot absorb moisture, condensation can’t occur within the surface of lenses.

What Do the Numbers Mean On a Rifle Scope?

The riflescope has a magnifying power, which shows the number of times a view field appears when compared by the view of a naked eye. Although there are scopes that are designed with fixed power, this means that the scope is adjustable. A typical example of a scope that is fixed powered is the three by 40; this means the rifle is designed with the ability to magnify objects or images 3x their normal size when compared to the view of the eyes, they are designed with 40mm objective lenses.

Other types of scope are designed with variable power and have a couple of numbers, like 3-9×40, 3-9×50. This time, you can use them to image starting from 3 – 9 times their main view with the naked eye. They are created with 40 mm objective lenses. The more the magnifying power, the more expensive the scope.

How Do Scope Adjustments Work?

The reticle is known as the crosshair; it is usually designed from etched or wire within a glass plate. The types of reticles are the duplex, mild-dot, bullet drop, special purpose, and many more — all designed for a unique purpose and specific calibers.

You can place the scope at the rear or front part of your magnifying lens. If you have your reticle positioned ahead of your magnification lens that is designed with variable power scope, you will observe a change in the sizes of crosshair once you zoom over an object. This adjustment will help you keep track of a target or an object in your scope irrespective of size and level of magnification. When the reticle is position at the rear part of your magnification lenses, then the crosshair finds it difficult to get magnified if there is a change in magnification.

What Do the Knobs On a Scope Do?

With the use of an elevation known as a vertical plane or a horizontal plane, known as the windage with an adjustment via the turrets or the knobs. You can easily adjust a scope, zero down it and focus on the desired target to the middle of your reticle. BDC, Mil- dot with other forms of reticles are created with different markings that are meant to aid the shooters to calculate the right spot at which they intend to take a shot, and this can most time be a bit longer when compared to the zero used.

So the next time you intend to get a riflescope, it is important to know the scope rings needed, and how to mount up the firearm. Although a lot of contemporary rifles are manufactured along with a scope ring been attached to them, these rings are of two different pieces or as a cantilever unit.

In the United States, most riflescopes are created with 1″ models. And has a sizable scope rings that suit the diameter of the scope tube.

In addition, depending on the number of factors – your cheek can weld directly on your stock, the size of your objective lens, eye relief, bolt life, actin type, etc. will all require the use of a riflescope ring with the right measure of height. Lower rings are created to get the scope closer to your rifle, so it needs a lesser positioning to get the perfect sight of the picture. On the other hand, using a higher ring will increase the height of the scope a bit higher on your rifle, and as a result, you gain more clarity for bolt action or a greater objective lens to suit your rifles.

Most people prefer expensive rifles, but at the same time, they fail to get them equipped with comparable scopes. Irrespective of how expensive or good your rifle is, the state of the scope outweighs other features. Most importantly, if you are aiming at becoming a good shooter, then practice should have a significant part. Remember, regardless of how sensitive or expensive an optic is, it cannot be remedied for a bad shooting orientation.

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About the author

Erik Himmel

A Part-Time Firearm Instructor

Hi, this is Erik. We all know firearms are dangerous, but only when one doesn’t know how to use and care for them. I have 15+ years of experience with different types of guns and for the last 10 years, I have taught numerous people how to hold and shoot a gun while staying safe and keeping the surroundings unharmed. My neighbors are some of my biggest admirers who enjoy talking to me about their guns, firearms safety and maintenance.

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