What is Parallax on a Rifle Scope?

Picture this: you set or position your rifle on a bench without touching the rifle. Then you peep into your rifle scope and see that the reticle is perfectly aligned and centered on your target. But then you make a quick face movement (maybe up or down or right to left) and notice the reticle move off the target. Now, this noticeable crosshair shift is what is known as parallax.

When there is a parallax error and your reticle doesn’t align with your target, you won’t nail your target. However, we have most rifle scopes to be parallax free but at a particular distance range which must not be exceeded else, you may have parallax error.

So, let’s give you further details on what is parallax on a rifle scope for better understanding. We’ll also walk you through how you can adjust and correct this parallax on your rifle scope so that you can focus on your target.

What is Parallax on a Rifle Scope? A Deeper Understanding

Parallax on a rifle scope is that error that you notice when there is a displacement or a shift in the reticle. This error is noticed when you look into your rifle scope from various angles. So, once your reticle shifts off your target, you’re having a parallax situation.  

This parallax issue is more noticeable when you’re aiming long range. However, you can still notice at short range distances. There are rifle scopes that are built to be parallax free at a specified distance. This specified distance is mostly around 50 to 150 yards. If you exceed the specified distance, there is a high chance you’ll experience parallax.

This also means that as you increase the magnification of your scope, parallax error tends to occur. Let’s check the illustration of parallax below for proper understanding.

Parallax illustration

A simple experiment for better understating is to try to hold up your phone and close one eye and look at this phone using one eye. Then switch the other eye by closing one eye and look at the phone again. You’ll observe that the view of everything beyond your phone tends to shifts from side to side when you switch your eye.

We can deduce two reasons why this happens. First, this is because the positions of our eyes are separated around 2.5 inches apart. So, each of these eyes views the phone at various positions. Another reason is that anything seen beyond the phone is practically beyond the phone.

Again, lay this phone on the table and view the phone with one eye and close the other. Then switch the eyes doing the same thing. You will notice that there’s still shifting in everything you see when the eye is switched. However, this shifting happens together with the table and the phone. This is because both the table and the phone are in the same spot.

So, the relation of this illustration to parallax is for you to assume that your phone is the reticle when you look through your scope. Then assume everything beyond your phone is your targeted image.

Therefore, once the targeted image and reticle aren’t focused on the same plane as you slightly shift your head, it will affect and displace your reticle.

So, our main aim is to prevent the reticle from moving away from the target. And this can only be done by getting rid of parallax and this is done by simply laying your phone on the table.

Hence, it’s best to focus your reticle and the target image on the same place so that the reticle will not move. Then you can have an accurate target shot.

Why Have I Never Experienced Parallax with my Rifle Scope?

If you shoot with optics frequently and you don’t notice parallax, then it’s because your rifle is parallax free at a set distance. So, moving your head around all you want around this distance range is fine and you won’t have any issue with cross hair displacement from your target.

Many professional hunters that usually shoot 250 yards and below don’t usually may not really have concern for parallax. This is because the majority of the centerfire scope already has their setting adjustment at 150 yards. This range is mostly okay for shooting distances below 250 yards.

Let’s check out more reasons why parallax error occurs in rifle scope below.     

Possible Reasons for Parallax on a Rifle Scope

Looking into your ocular lens at an image from afar with your scope helps you magnify the image. Now, this is where every light ray that enters the optic gets focused so it gives you a projected image.

However, when parallax error happens, the image projected tends to be far away from the reticle crosshair shown in the optic. The projected image can be far away from either the front or back of the cross hair when parallax occurs.

What we want is for the target as well as the reticle to align on the same focal plane. If not, you will miss your target and this can be pretty frustrating to any shooter.

In all these parallax issues, the good news is that there are ways you can adjust this parallax error and get the right focus. So, how do you do this? Continue reading and you will learn about this parallax adjustment for your rifle scope.

What’s the Importance of Parallax in Rifle Scope?

We cannot overemphasize the importance of knowing when you have a parallax situation and doing the right adjustments. Apart from most reticle scopes featuring adjustable parallax, we still need to know how we can correct the parallax situation of your target image.

In your hunting games, shooting a distance range of about 300 yards below may not really cause concern. This is because parallax has no effect on your shooting accuracy at close range. However, once you know your shooting range will exceed 300 yards, then it’s crucial you take parallax error into account. You don’t want your shooting to be off target because that can be pretty frustrating.

Understanding the Depth of Field or Focus

The depth of focus in optics such as binoculars, riflescopes, and so on, is pretty important. For instance, when using some binoculars, you can view object images at 100 yards and at 125 yards which both of them will show in the focus. The reason is that the binocular features a deep depth of focus.

However, other binoculars may require you to adjust the focus even if the distance changes slightly (say it changes by only 5 yards). This is due to the fact that the binoculars feature this narrow depth of focus.

Although the parallax adjustment knob may also be regarded as a focus, that’s not exactly its job. But due to how the adjustable parallax riflescope is built, there is the feature of a narrow depth focus. And this is because the adjustment of the parallax should do a perfectly fine lens movement inside the scope.

For this reason, when you adjust the parallax to suit a particular distance, the target object is placed in the middle of the scope’s narrow depth of focus. Now, a fixed parallax rifle scope, usually has a deeper depth of focus.

Adjusting Parallax to Correctly Align with Your Target

Practically all modern rifles tend to have parallax correction in their features. So, the main purpose of correcting parallax on our rifle scope is so that your rifle scope can align on the same focal plane with your target.

We usually have the occurrence of external parallax (also known as side focuses or adjustable objectives) in scopes that have their magnification greater than 10. For parallax adjustments to be done, adjustments are done at the objective lens that has a rotating dial with yardage incremental distance markings.

This yardage marking mostly comes as incremental of 50 or 100 yards which helps in parallax setting correction.

Nowadays, most rifle scope features parallax adjustment dials located at the left side of the turret housing. Now, this dial is a type of parallax correction mechanism located at a pretty convenient spot for many shooters. This parallax adjustment knob enables the shooter to make parallax corrections and adjustments of the targeted image back and forward. So, this parallax adjustment helps align the focal plane of the reticle.

So, let’s further look into the details below on how you can adjust rifle scope parallax error on your scope.

Steps on Parallax Adjustments

·         If you want to properly find the accurate position of the dial then establishing a clear and clean target that can stand out excellently well from its background is the key. Doing this will further ensure that the correction you’re doing for the parallax error on your rifle scope is valid. So, to do this, focus your reticle by looking through a plain view like the sky or a plain white wall.

·         Ensure you don’t look too long but only for a few seconds else your eyes can automatically attempt to focus the reticle.

·         Then proceed to setting and securing your riflescope to a resting position. Now ensure the magnification of the scope is at its highest peak. Then peek into the rifle scope to view the targeted image and begin to move your head up and down or left to right.

·         If you notice the reticle dancing about as you move your head, then you’re having a parallax error situation. So, you’ll need to check into your yardage indicator which is on your parallax adjustment or parallax knob for corrections.

·         The parallax correction situation for your scope will mainly depend on your magnification level and the range. You may even need to do a full revolution dial for the parallax correction.

·         So, keep doing the adjustment until you notice a sharp reticle with your targeted image. And ensure the image is locked on. Both the reticle and targeted image should be visible without you shifting focus.

·         However, if you’ve done your adjustment and have still not gotten a perfect aiming point, just keep on making fine corrections. Do this correction until your angle can be moved as far as possible at the same time sustaining that full and clear image through your rifle scope.

·         Now, after getting full satisfaction with the adjustment, you should leave it that way. There won’t be any need for adjustment anytime soon except there is a change in circumstances or you have an extreme shot range.

Extra note: we recommend that whenever you plan on purchasing a rifle scope, take into account your shooting distance as well as the adjustment system. Don’t just pay attention to how stylish the adjustment is, but have your focus on the adjustment itself. The adjustment will go a long way in how you nail your shot.