What is Side Focus on a Scope? – Step-by-Step Instructions

Scopes come with a lot of features. New features raise new questions, one of them being…

What is side focus on a scope?

Let’s find out together.

What is Parallax?

Parallax is the difference in the appearance of objects when viewed from different angles. When you move your eyes across the exit pupil of a rifle scope, the reticle appears to move relative to the target. This is called parallax.

An Analogy on Parallax

A car’s speedometer is designed to be viewed by both the driver and the passenger at the same time. This allows the driver to see how fast he or she is going while also allowing the passenger to see how fast the car is traveling. The driver adjusts the focus of the scope to match the distance to the target. Parallax is eliminated when this adjustment is made.

Parallax is an effect that occurs when the viewer moves away from the object being viewed. This causes objects to appear to move relative to each other. In this case, we see that the target appears to move as the shooter moves away from the gun.

Note: If you want to know a complete guide and tutorials about scopes click HERE.

Removing Parallax

Parallax error occurs when your eye moves relative to the scope. You need to adjust the side focus mechanism until you see the target in clear focus. Then turn the side knob to move the crosshairs into place.

Parallax needs to be corrected before shooting. A scope without parallax adjustment is useless.

What Is A Side Focus On A Scope?

Most people who own scopes know about windage and elevation adjustments. But there is another knob on the left side that adjusts the side focus. Side focus means that the reticle appears to move when you turn the scope around. You might think this is weird, but if you’ve ever used a rifle scope, you’ll understand what we mean.


Parallax is when you move your eye slightly while looking through a scope, causing the reticle to appear to be floating around. This happens because the reticle isn’t placed on the correct focal plane. A parallax adjustment knob lets you adjust the focal plane so that the reticle stays on target.

Parallax is an effect caused by the movement of the target relative to the shooter. When you shoot a rifle, the bullet travels along a straight line, but if there is any movement of the target, the bullet will miss the target. Parallax correction allows you to compensate for this movement.

You can use a bobblehead method to test your parallax settings. This is a very easy way to do it.

Note: If you want to gain information on How to Dial in a Scope click HERE.

Focal Plane

Generally, when talking about the focus plane on a scope, we are talking about the first focal plane. This is usually not what we are talking about. We are talking about the reticle being on the same focal plane as the target. Meaning, we need to see the reticle on the object we want to aim at.

Your eyes focus on different parts of the image depending on what part of the image you’re looking at. When you move your head, your eyes stay focused on the same point on the image. This means that when you move your head, the image doesn’t change.

Red dots are very useful because you can see them easily without having to move your head. But if you use a scope, you won’t be able to place the reticle on your target. That’s when you turn off the side focus parallax knob.

What is Side Focus on a Scope

What is Side Focus on a Scope?

Other Parallax Adjustment Locations And Pros And Cons

Side focus adjustment is better than adjustable objective because you can adjust the magnification without having to change rings. The adjustable objective is better than side focus because you can use both hands while adjusting magnification.

Side focus adjustments are great for hunting applications where you don’t know what your distance will be. You can easily change the side focus without having to get out of your vehicle. These scopes are usually more expensive than others because they are made by high-quality manufacturers.

Adjustable objectives are great for competition shooters who know exactly what they’re aiming at. They are easier to use than side focus knobs but are harder to adjust. They are also heavier than side focus knobs.

Note: If you want to gain information about Who Makes Redfield Scopes? click HERE.

When does side focus become necessary on a rifle scope?

Side focus is needed when it’s counterproductive to take your eye off the target. A sniper scope should be focused on the target. You do well to maintain visual contact.

Parallax adjustments are needed when shooting long range. A rifle should be adjusted before going out to hunt. Adjustments can also be made while sitting on the bench. Shooting targets at close ranges do not require any adjustments.

Deer hunters should be careful about using scopes with high magnification. You may lose sight of your target if you’re too close to the edge of the field.

Parallax occurs when the scope is out of focus. Crosshairs do not stay still but move around on the target.

When focusing, the reticle should stay still relative to the object being viewed. A scope with parallax will cause the reticle to move when you adjust the focus.

Note: If you want to know How to Paint a Rifle Scope click HERE.

Correcting and Adjusting Rifle Scope Parallax

Parallax correction is a useful tool for long-range shooting. It allows you to see your target more accurately.

Parallax correction is the process of making sure that both the target and the reticle are in the same focal plane. If this isn’t done correctly, the target may appear soft or blurry, while the reticle remains sharp.

Focusing Your Reticle

Before adjusting for parallax, make sure your scope is in focus. A simple way to do this is by looking through your scope at a bright, preferably distant background. You should be able to see the reticle. Then, turn the focus ring until the reticle is sharp and visible to your eye.

Parallax correction is an important part of shooting. You must make sure that you adjust this correctly. Your parallax correction should be consistent.

Correcting Parallax

Most modern riflescopes have a parallax correction system that allows you to adjust the image of your target backward or forwards to match the focal plane (the distance at which the bullet hits the target) of the reticle. Some of these dials are marked with yardages in increments of 50 or even 100 yards to help you correct your aim.

A clear target that stands out from the background should be used to find the right position of the dial. Your rifle should be secured in a safe resting position before you start shifting your head back and forth. You should use the magnification at its highest setting to see if the dial is in the right place.

Parallax issues occur when the reticle moves relative to the target as you move your eye. This causes the crosshairs to appear to move to the target. You need to adjust the parallax settings to correct this problem.

Adjusting the scope is done by turning the knob or rotating the barrel. A scope is adjusted by moving the crosshairs closer together or further apart. Scope adjustments are usually done when hunting games.

Adjusting a rifle scope is easy. Just follow these steps:

  1. Hold the rifle scope in your hand
  2. Look through the scope
  3. Move the focus ring until the image appears sharp
  4. Leave it there
  5. Repeat step 3 and 4 until the image is clear.
  6. Once you’re done adjusting, leave the scope alone.

If you want to know more information about scopes click Here.


We hope that you have a better understanding of side focus and parallax!


  • John Moses

    John is the Editor in Chief here at The Outdoor Stores. His area of expertise ensures that there is no one better to suggest which rifles are most suitable for your hunting experience. He is also available for you to contact him personally to discuss the types of animals you want to hunt and the terrain you will be hunting on. Feel free to read his posts for expert opinion on Rifles, Scopes, Rangefinders, Bonoculars and Monoculars.

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