What Is Parallax On A Scope? (Parallax Adjustment)

When you first get into shooting, you have to take some time to learn the basics. When shopping for your first scope, chances are you read phrases like “parallax adjustment” or even “parallax free”.

But the reality is most new shooters don’t even know the answer to this basic question: what is parallax on a scope?

Gun scope parallax is when the reticle and the target appear to be on different planes. If you have a parallax issue, this means the reticle will appear out of focus to a shooter and cause aiming errors.

To determine if you have a parallax issue on your gun scope, place your optic in a fixed location and move your eye in different locations around the eyepiece. If you notice the reticle moving, you have a parallax problem.

Gun Scope Parallax

What Is Parallax On Scopes?

Parallax on scopes is the inconsistency in your rifle scope’s view when you move your eye from one side of the eyepiece to the other. The rifle scope reticle will appear to be out of focus in relation to your specific target. The result is that your target appears to move relative to the crosshairs, making it difficult to get a precise shot.

The reality is that parallax occurs on just about all modern or new rifle scopes. From the best AK47 dot sights to the best modern Vortex deer hunting scopes, parallax adjustment is a common feature.

In this guide, we’ll dive deeper into the meaning of rifle scope parallax, how to identify parallax problems, and how to fix them.

What Is The Difference Between Fixed vs Variable Parallax Scopes?

The main difference between fixed and variable parallax scopes is their adjustability for different target distances. Fixed parallax scopes are set at a specific distance with no user-adjustable settings. However, variable parallax scopes offer adjustability to match various target distances through mechanisms like Adjustable Objective (AO) or Side Focus (SF).

The table below summarizes the main differences between variable parallax & fixed parallax scopes.

Aspect Fixed Parallax Scopes Variable Parallax Scopes
Parallax Setting Set at a specific distance (e.g., 100 yards/meters). Adjustable to match various target distances.
Adjustment Mechanism Fixed, no user-adjustable parallax settings. Typically features an Adjustable Objective (AO) or Side Focus (SF) for user adjustment.
Ease of Use Simple, no need for manual adjustments. Requires manual adjustment to match the target distance.
Versatility Limited versatility for varying distances. More versatile, suitable for different shooting scenarios.
Common Usage Often used for specific applications at a fixed range. Preferred for dynamic shooting situations with variable distances.

Reticle Focus

Before we get into exactly how to correct a parallax error, the first thing you’ll want to do is make sure your reticle is in focus. You can do this by adjusting the reticle focus ring until the crosshairs are sharp and clear.

Line up your eye behind your objective lens and sight in a target just a few yards away. Regardless if you have a first focal plane or second focal plane optic, they normally adjust the same way. Check out our guide if you are not sure of how to adjust your scope settings to focus your reticle on a target image.

Note: The process is very similar no matter if you’re adjusting rifle scopes or even spotting scopes.

How To Identify A Parallax Error

a picture of rifle scope parallax

In order to be able to fix a parallax error you first need to be able to identify when you have an issue. If you think your scope might have a parallax issue, there’s a simple test you can do to find out.

  1. First, take your rifle and scope and set them up on a solid surface like a table or counter.
  2. Look through the scope and focus on an object in the distance.
  3. Without moving the scope or rifle, try to move your eye around the eyepiece. If the reticle appears to move around your target, then you probably have a parallax issue.

You will know when you need a parallax adjustment if you see any of the following things.

  • The reticle appears out of focus or blurry.
  • The target seems to move around as you move your head – But is clear when looking through the scope directly.

How To Fix A Parallax Issue?

Now you know how to identify a parallax issue that can cause terrible accuracy problems. To eliminate parallax issues you need to get the scopes reticle and target to be on the same focal plane.

Note: Parallax adjustment is not an issue for most scopes when firing from within 250 yards.

Assuming your scope has a parallax adjustment feature, here are the steps you need to take:

  1. Use a stable aiming platform to align your rifle at a target at a known distance
  2. Adjust the parallax knob or ring until the reticle becomes clearer and you have a clear sight picture.
  3. Finally, do the movement test – Keep the scope still & move your eye around side to side.

If your crosshairs are still moving off the target, repeat steps 1-3 until you have a clear image and your target image & scope are on the same optical plane. Keep making small adjustments until you get it just right. Making optic adjustments is a very important skill. It doesn’t matter if you’re trying to make an AK front sight adjustment or rifle scope adjustment. However, parallax does not necessary matter for all types of shooters.

When Does Parallax Not Matter?

Eliminating parallax is not a huge issue for everyone. For close-range hunters, parallax doesn’t really matter. In fact, most close-range hunters don’t even know what parallax is.

This effect is most pronounced when you are looking at an object through a scope from long range, more than 250 yards. At close range, your eye is much closer to the scope than it is at long range, so the parallax effect is much less pronounced.

This is why close-range hunters don’t worry about parallax – they just shoot what they see. However, just because you’re a close-range shooter doesn’t mean you can avoid leveling your rifle optic. That is still 100% necessary or your accuracy will suffer, even from close distances.

What Scopes Have Parallax Adjustment Features?

Nowadays, most scopes come equipped with a parallax adjustment turret to make adjusting parallax easy. Depending on the type of scope you have, parallax will be set at a certain distance.

Many hunting scopes also come with a fixed parallax in the 150 yard range. However, if you buy a rifle scope with adjustable parallax you will have some added versatility. And as you can see trying to adjust parallax is not rocket science.

FAQs – Parallax Adjustment

Does parallax affect accuracy?

Yes, parallax does affect accuracy. However, it does not have as much of an impact at close distances as it does at longer distances. For example, if you are trying to shoot a target that is 300 yards away, the impact of parallax will be much greater than if you were trying to shoot a target that is 80 yards away.

What does parallax setting 100 yards mean?

It means that the rifle scope is set to be Parallax Error-Free at 100 yards. Parallax error can cause the target to move position in the field of view as the shooter's eye moves slightly left or right of the scope's central axis. A rifle scope with parallax adjustment can be set so that the image of the target is aligned with the reticle at a specific distance--such as 100 yards.

What does the parallax knob do on a scope?

The parallax knob on a scope is used to make parallax adjustments. Shocking right! Parallax occurs when the position of an object changes relative to the observer, and it can cause errors in estimating range. The parallax knob allows you to adjust the position of the reticle so that it appears to be stationary when you look through the scope. This ensures that your shots are accurate, regardless of your distance from the target.

Does magnification affect parallax?

The amount of parallax increases with magnification. This is because the angle between the object and the observer becomes smaller as magnification increases, which means that the difference in their positions becomes greater. This greater difference in position results in a larger parallax.

Do fixed power scopes have parallax?

Most fixed power scopes do have parallax set at an intermediate distance. This is because, as magnification increases, the effect of parallax becomes more pronounced. So, by setting the parallax at an intermediate distance, it allows for a greater degree of accuracy and eliminates the need to adjust the focus each time you switch targets.

The Bottom Line

By now you are an expert rifle scope parallax. The key is to get both the reticle and target in the same focal plane. It might sound tricky at first, but we have laid out the exact steps you need to eliminate parallax issues on your scope. Remember that each scope is slightly different so take a look at the specs. Let us know how you make out!

About the author

Charles Neser

I'm a life long hunter & gun lover. Currently pursuing my Master's Degree (M.Sc.) in Animal Nutrition at University of the Free State.

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