How does a rifle scope work?

We all know about the scopes used in a rifle but do not know how it works, here’s how the scope of a rifle works:

The anatomy of scope is more complicated on the inside than the outside of the rifle scope. The lenses are the heart and soul of your scope. From the front to the back you have an objective lens called focus lens, magnification lenses, and then the ocular lens. The lenses are coated to reduce reflection or glare when scoping. Lesser the light a lens reflects the more light is transmitted back to the eye. The primary light-gathering lens is the objective lens, so the diameter and the coating on this lens can make your scope regarding low light abilities. The objective lens fixed inside the objective lens assembly.

The next lens behind is the focus lens, fixed in the focus lens assembly. These lenses can be attached or adjusted. In these lens scope, the focus lens is default set to be parallax-free at a specific range given, usually 100 meters or 100 yards. In the model with a parallax adjustment knob, rotating the knob adjusts for parallax at various intervals by moving the assembly closer from the objective lens assembly. In practice, it means that as you can change the knob towards infinity by which the lens gets further to the lens. When adjusting for nearer objects, the lens assembly moves back to the ocular. Usually, the scopes with parallax adjustments can be dialed into the parallax free at ranges from 50 yards to infinity. Check out this website to know more about scopes.

Heading back further into the ocular lens within the main tube we arrive at the erector tube of the scope; the erector tube has both the reticle assembly and the magnifying lens. In a variable scope the lenses change their position inside the erector tube as the power ring is rotated, nearer to the objective on high power and nearer to the ocular on less power.

The reticle is what is generally called the crosshairs. The reticle can be either in the front or behind the magnifying lens. In the first case, with the reticle in front of the lenses, it is known as a first focal plane. In this situation, changing the magnification of the scope will result in the crosshair to appear to change its size from the viewpoint of the shooter.

In reality, the crosshair stays the same size concerning its target. It is a huge check mark on the plus side for the first focal plane. Even though the reticle maintains its relative size, an aim of 5 dots tall at lower power is still five dots tall at a higher power meaning that all calculations of the elevation, range, and holdover stay the same at any power setting.