Parallax in Scopes: What It Is and How to Adjust It

Are you experiencing a strange “double vision” effect when you adjust the objective lens on your rifle scope? You may be dealing with Parallax.

This article reveals exactly what parallax is, why it’s important to know about, and how to adjust it on your scope. Welcome to our complete guide to Parallax in Scopes!


Parallax in scopes is a phenomenon that occurs when shooting long-range distances. When you look through a scope, your eye position is not in line with the scope’s reticle. This means that while crosshairs may appear to be on target, your shot may land somewhere else on the target. While this phenomenon doesn’t affect every scope, it brings up important considerations for shooters using precision rifle scopes for hunting, competition and tactical applications.

In this guide, we’ll discuss what parallax is and why it’s important to understand for those using long range scopes. We will also explore the types of parallax adjustments available on the market and their uses as well as how to properly adjust parallax on your own rifle scope. By understanding what causes parallax and how to correct it with easy steps, you can master precise shooting at any distance with confidence. Let’s dive in!

Definition of parallax in scopes

Parallax in scopes is a common issue that can affect your sight image and accuracy when shooting. It occurs when you look through a scope and the reticle appears to move around or scroll horizontally, vertically, or both as you look for targets. This can be a problem because it makes precision targeting difficult, if not impossible.

To understand parallax in scopes, we must first look at what causes it and then how to adjust it.

Parallax is caused by the fact that scopes are designed with two optical systems: the integrated reticle and the scope’s lens system. Both of these components are positioned in separate planes at slightly different angles, thus creating a kind of optical discrepancy that results in the reticle’s movement or scrolling effect when viewed through the scope.

Parallax adjustment can be found on most modern scopes, although not all models have this feature. It’s important to understand how to adjust your particular scope so that you can reduce any associated errors while shooting. Typically found on an adjustable side turret (which looks like a small knob), parallax adjustment works by aligning the objective lens angle with that of the reticle – eliminating any appearance of movement or scrolling while looking through the scope. Make sure to follow your scope manufacturer’s instructions on proper parallax adjustment procedures.

Importance of understanding and adjusting parallax

Parallax occurs when objects located at different distances appear to have a change of position when viewed from different angles. This phenomenon may seem unimportant, but understanding and adjusting parallax on a scope is important and can significantly help improve your accuracy for shooting.

Parallax adjustment offers the advantage of eliminating or at least significantly reducing errors due to parallax distortion. While some scopes are designed with an adjustable objective (AO) feature that allows you to adjust the scope’s focus for Parallax control, most scopes do not offer this feature. Therefore, it is important for shooters to understand the phenomenon of Parallax and how to make adjustments on their scope if needed.

Scope Parallax Adjustment -The Firearm Blog

Understanding how parallax works can also help shooters improve their accuracy while using any given scope. Most modern scopes are designed with a type of optical focusing mechanism called an erector system which helps compensate for perceived image shifts when looking through the scope at various distances. Understanding this erector system and how it works in relation to parallax can be extremely helpful in improving your accuracy as a shooter. It’s important that shooters learn how to recognize its importance in a scope’s performance and know how to properly adjust it if needed.

By understanding the importance of proper parallax adjustment and learning how to make these adjustments properly, you can greatly increase your accuracy while shooting your rifle or handgun regardless of whatever type or model of scope you use.

Understanding Parallax in Scopes

Parallax in scopes is an optical phenomenon in which the image of a target appears to move in relation to the reticle when the shooter moves their eye behind the optic. This can lead to confusion when making precision shots and should be taken into account when adjusting a scope.

Parallax occurs when the target is not on the same focal plane as the reticle and as a result, they appear out of alignment at different distances. It can produce extreme errors in point of impact at extended range and is one of the lesser known concepts studied when shooting accurately with a scope.

To understand parallax it is important to know what causes it- specifically, an optical imbalance between both sides of an uncovered objective lens creates two focal points for light rays that enter from both sides instead of converging on a single point. To minimize parallax, shooters must make sure that light enters from only one side so that all rays pass through one point rather than being split into two focus points- this will ensure improved accuracy by allowing targets at any distance to fall in line with the reticle.

To adjust a scope for parallax it is necessary to first adjust accuracy for your environment- this includes setting your magnification power, windage, elevation and zeroing. Once these elements are established you should set your parallax adjustment based on feedback from your chosen sighting technique such as “Center Hold” or “6 o’clock Hold” – each technique requires its own specific adjustments which should be performed while maintaining eye relief and sight picture consistency between shots. Once complete you will have adjusted you rifle scope for precision accurate shooting!

Definition and causes of parallax

Parallax is an optical effect emanating from the misalignment of two or more optical components that results in a change in the apparent position of an object or image when viewed from different angles. When viewing through a rifle scope, it is commonly defined as an apparent shift of the reticle out of its true position relative to the target as you move your eye around inside the eyepiece. Parallax can affect your accuracy when shooting at different ranges due to its impact on your aiming point and can be caused by several things.

One common issue is either improperly adjusted reticles or poorly aligned crosshairs with respect to each other, resulting in a misplacement of the riflescope’s reticle relative to where it should be when on target. Add this with poor eye relief adjustment (defined as how far away from your eyepiece you need to be to see correctly through your scope) or even slightly angled mount rings as well as mounting them too low and you have yourself a big impact coming from small issues that make up parallax.

Moreover, most mid-range scopes will not have any type of adjustment for parallax so you may want to invest in higher quality scopes if this issue arises frequently. This is because there are some premium scopes that do offer parallax adjustment knobs; these knobs work by moving two parts inversely relative to one another so that they remain parallel, ensuring that no image distortion occurs due to misalignment. On some occasions, where erector tube assemblies are properly matched with their companion lenses, parallax adjustments are unnecessary but often times we find ourselves wanting one regardless so we can fine tune our aim even further than what our eyes can detect at certain ranges and distances.

Impact of parallax on accuracy and precision

Parallax is an optical effect that affects the appearance and accuracy of what you see in scopes. It can also affect the level of precision with which you make shots with your rifle. When parallax is not adjusted correctly, it can cause the point of aim and the point of impact to be misaligned, resulting in unwanted deviations from your target’s center mass.

This difference is known as parallax error, or “parallaxing”, and is a form of shooting inaccuracy caused by improperly set up optics. It is important to know how to adjust parallax on your scope to ensure that your shots are precise and accurate every time you shoot. By adjusting the amount of parallax on your scope (or removing it entirely), you can better control where bullets hit even at longer distances.

Parallax adjustment requires a steady hand since any movement while turning the adjustment turret will affect your accuracy significantly. The goal should be to move the reticle over the target at all ranges without it drifting off-center due to adjustable magnification levels or eye position changes at various ranges. By adjusting for parallax, shooters can increase their effective range by creating a more rigid sight picture—one less affected by minor shifts in head or eye position relative to their riflescope’s eyepiece when zoomed in at long distances.

Understanding and Correcting Parallax - The Shooter's Log

The amount of parallax error varies based on distance and angle, but most commonly occurs when shooting beyond 100 yards/meters since bullet drop increases exponentially as distance increases. A slight alteration in eye position or breathing technique (inhaling then exhaling slowly) changes where shots land within seconds—even if minor adjustments are made along the way each time without fail. Parallax adjustments should therefore be made often when hunting or shooting for precision at extended ranges for consistent accuracy; this might mean adjusting before each shot taken from a certain distance range or using a predetermined yardage setting with significant magnification levels that aren’t adjusted until targets move closer or further away than expected/anticipated distances dictated ahead of time.

Types of parallax: inherent and adjustable

Parallax refers to the perceived shift in the position of an object when seen against a distant background. In optics, parallax can be a major problem when it comes to accuracy and precision. There are two types of parallax: inherent and adjustable.

Inherent Parallax: Inherent parallax is generated naturally by any optics device that uses a curved lens or mirror system. It’s caused when the entrance pupil (the point at which all the light entering the scope devices arrives) isn’t aligned with the scope’s optical axis, resulting in varying amounts of error depending on where your head is relative to that optics system. Inherent parallax cannot be adjusted or reduced without significant modification to the device itself.

Adjustable Parallax: Adjustable parallax is also called focus adjustment and occurs in most modern scopes, particularly those designed for precision shooting like sniper rifles and target rifles. This type of parallax can be controlled externally via a knob or other mechanism mounted near the eyepiece on your scope, allowing you to configure it optimally for each situation you might find yourself in while shooting, whether it’s moving targets or stationary objects at varying ranges from you.

III. Adjustable Parallax

Adjustable Parallax scopes feature an adjustable objective lens (AO) or side focus knob. This is specifically designed to provide the necessary parallax adjustment in order to guarantee a clear, sharp image when aiming at any distance. The adjustment knob moves the reticle in relation to the image so that when your eye moves, you see a change in your aim point.

The primary benefit of AO scopes is that you can adjust for parallax without needing to change position or compromise your form. The knob should be marked in yards/meters from a set minimum which is normally 10 yards (or meters) and indication of up to infinity with graduations as low as 5 yards available on higher end models.

The length of travel also varies; Airmax series scopes generally have around 45 MOA travel while ED (extra-low dispersion glass) models can have up to 70 MOA travel which provide added flexibility at extreme ranges.

Adjusting parallax with a side focus knob

Parallax adjustment on a riflescope can usually be done using the side focus knob that is included with the scope. The scope’s internal mechanism moves the reticle within the scope and refocuses it to eliminate parallax errors. While adjusting parallax can be time-consuming and potentially confusing, it is not a difficult process if you understand how to do it correctly.

First, unscrew the side focus knob located on the left side of your scope’s body using your fingers or a coin or screwdriver if necessary. Once you’ve unscrewed it halfway, you should see an arrow pointing to either 50 or 100 yards. This arrow indicates that this is where you need to start in order to adjust your parallax error. Position the crosshair so that it is aligned with whatever target you are shooting at.

Next, turn the side focus knob up while taking note of any minute shifts in reticle position relative to your target. Once you no longer see any movement in your reticle as you turn up (clockwise) adjust until there’s only minimal correction required, then turn right (counter-clockwise). If needed continue turning clockwise until there are no more adjustments required and your reticle holds steady on whatever target you’re shooting at – this indicates that parallax has been properly adjusted for those distances!

Adjusting parallax with an adjustable objective lens

For scopes with an adjustable objective (AO), parallax can be quickly and easily adjusted by rotating the AO focusing knob. This type of adjustment is often found on variable power scopes and was formerly limited to higher end models, but is now becoming more commonplace even on modestly priced scopes.

When adjusting parallax on a scope with an adjustable objective, first use your center crosshair to aim at a target at least 100 yards away or farther. Next, focus on the target using the eyepiece focusing knob until it appears as clear as possible. Then slowly adjust the AO knob, watching through your scope to make sure there is no shift in the reticle pattern when you turn it. Continue adjusting until the reticle remains in fixed location when you move your eye around through the eyepiece—this indicates that parallax has been corrected.

Test shooting is key to making sure that this adjustment was done correctly and should be done after any change in parallax setting. Be aware that some end users have had difficulties setting up their parallax correctly even with an AO mechanism due to errors and misalignment between what they see in their scope’s image during adjustments in comparison to the actual shooting conditions and distances used for testing later on down range targetsets.

Correcting parallax at different distances

When using a scope for shooting, it is important that the cross hair optics are aligned correctly with the point where the bullet will exit the barrel. This is known as correcting parallax and is a very important step to take in order to get accurate shots. The ability to correct parallax depends upon two factors, how far away you are from your target, and which type of scope you are using.

At close distances (under 25 yards) most scope manufacturers suggest leaving Parallax at its default setting of 150 yards, regardless of which type of scope you are using; this will usually provide acceptable accuracy as most shots taken at short ranges do not require high precision.

Correcting and Adjusting Rifle Scope Parallax — Outdoorsmans

For shots taken between 25 and 200 yards away, rifle scopes can typically be adjusted to their intended distance for Parallax so long as the rifle is mounting on an acceptable and stable platform. This can be done by adjusting the Parallax adjustment knob on your scope until there is no visible movement when you move your eye around behind it. Make sure to adjust this knob carefully so that no damage occurs from mishandling it.

For shots ranging from 200 to 500 yards, telescopic scopes are usually more accurate and their parallax can be adjusted precisely. For these longer distances, it is important to adjust the Parallax knob to the exact distance of the target to ensure accuracy.


In conclusion, parallax in rifle scopes is an important consideration for achieving accuracy in shooting. To set up parallax properly, it is important to understand the basics of parallax and the differences between fixed and adjustable objectives. It is also helpful to have a basic understanding of how reticles are designed and how they are affected by parallax adjustment.

By taking into account all these factors, you will be able to achieve maximum performance from your scope no matter what kind of target distance or condition you’re facing.

Thanks for taking the time to read this guide on Parallax In Scopes: What It Is And How To Adjust It!

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