How To Determine Eye Relief On a Rifle Scope

Do you often find yourself hunched down when you want to determine the whole field of view with your rifle scope? Have you ever been on a hunt and suddenly lost sight of your target just because your rifle scope was not focused or became too blurry?

The problem with your rifle scope might be caused by a number of reasons. Checking the eye relief is one of the solutions to this problem. If you’re unfamiliar with the phrase or want to learn how to adjust eye relief on a rifle scope. Then I invite you to keep reading as I lay down all you need to learn about rifle scope eye relief. At the end of this article, you would understand how to determine eye relief on a rifle scope.

Finding The Eye Relief Of Your Scope

The eye relief of a rifle scope is the distance that must be between your eyes and the lens of the rifle scope for you to get a full and clear image from the scope. If you move forward or backward from this position, you would lose some visibility. Before you measure this scope number, you must first understand why you actually want to do it.

Most rifle scopes have their eye relief on the website of the manufacturer. You can also find this information on the page where you got the product from, so if you’re simply trying to recall what it was, you can always go back and check.

Another method would be to mount the scope on your rifle, then position your eye so that you can view the entire image, and then use a ruler or tape to measure the distance between your eye and the eyepiece.

One of the reasons why I measure the eye relief of my rifle scope is when I need to purchase a new scope. If you’re thinking of buying a new scope, then you would want to measure the eye relief of your old rifle scope (the one you are used to). If, for example, your old scope has a 3″ eye relief (meaning that your eye must be 3 inches away from the lens) and this 3″ scope usually feels too tight or you’ve been hit by a scope bite, then a scope with 3.5″ or more eye relief would work best for you.

How To Measure A Scope Eye Relief

The quoted eye relief on the product page may not be correct, especially when you go for a lower-cost rifle scope. In situations like these, it might be useful to assess how much eye relief you actually have. If you learn how to do this yourself, you would be able to get the proper eye relief of the scope.

If you’re used to low-cost optics, it’s easy to adopt the idea that “long eye relief is always better,” but this is simply because you’re used to rifle scopes with long eye relief. If the scope eye relief is more than 4.5 inches, it might be difficult for you to get into a comfortable shooting position.

If you want to know the proper eye relief you’re getting from your scope, the only way to be sure is to grab a tape measure or ruler and have someone measure the distance between the eyepiece lens and your eye as you hold still in the shooting stance.

It’s common, especially for beginning shooters, to lean in towards the rifle scope instead of adjusting eye relief. As a result, the chances of a scope bite will increase ( when the eyepieces lens hits the shooters eye). The industry standard eye relief for rifle scope is between 3 – 4.5 inches.  The point at which you can view the entire picture is referred to as eye relief.

When You Want Short Eye Relief

There are situations in which you may want a short eye relief on your scope. If you’re shooting a smaller rifle, such as a .22 rifle with no adjustable stock, you might have to move closer. Because of their firing stance, military-trained shooters who shoot NTCH sometimes choose scopes with a short eye relief.

If you use glasses, the standard eye relief may be affected. Scope makers often offer several rifle scopes with varying standard eye relief that are marketed expressly for specific use.

Long Eye Relief

Long eye relief is very necessary when handling a rifle with heavy recoil. During the scope mounting, ensure the rings are adjusted so that the eyepiece lens is in the ideal position for your eye before you tighten the ring screws.

Scope Eye Relief and How It  Is Adjusted

An essential rifle scope parameter is eye relief. It specifies where the scope should be mounted on the rifle to provide the shooter with a comfortable shooting posture. Remember that eye relief is the distance your pupil must be in order to see the whole field of vision without any clipped pictures from your scope.

It is not possible to actually change the eye relief of a rifle scope. That is why I would highly recommend that you purchase a short eye relief or long eye relief scope, depending on what you are shooting and how you want to shoot, instead of looking for a way to make an adjustment to the scope. The best you can do is move the scope’s mounting away from your eye. If you’re not getting a comfortable scope mount position, try changing the point where the scope ring holds the scope tube.

If the image is hazy, out of focus, or some parts of the field of view are obscured by the scope, then you are not within the scope’s eye relief. Many hunters choose a long eye relief scope because they often shoot larger calibers with higher recoil. Whatever you want to use your rifle for, you’ll need the proper eye relief.

If you want to make an adjustment to the location of the rifle scope to get the correct eye relief, then you have to start by getting into a comfortable shooting stance. Hold the rifle on your shoulder and align your head as you gaze into the scope. Make sure you’re at ease and comfortable.

You can get someone to help you if your scope ring is already loose,  gently move the scope ring forward or backward until you get a good scope eye relief that aligns with your eyes. Then secure the scope rings to the scope base on the rifle with the ring screws.

What is the significance of eye relief?

Many shooters unwittingly take their guns, attach their scope, and set out for a day of target shooting. Some of these people return with bandages on their brows.

This is because they did not get the proper eye relief for their shooting type. It’s a good idea if you spend some time trying to understand your rifle and shooting purpose so you can get a good eye relief. This would save you from harm and minimize the chance of “scope bite.” Scope bite happens when your scope is placed in such a way that you must hunch up close to see clearly. When shooting a powerful recoil rifle, don’t go too near to your scope, the recoil will force your scope to crash into your eye. 

Good eye relief allows you to see the largest, sharpest, and brightest image possible. An unpleasant dark ring will appear around your image if the optic is too distant or too close. Don’t assume that you can just hold the optic at the right eye relief and that would be it. 

Another issue caused by poor eye relief is clipped visuals. This reduces your effective FOV and lowers the image quality of your scope. This can induce severe migraines and be quite distracting.

Other Important Scope Specifications

Field Of View

The ability to change your field of view is a beautiful thing. Most individuals find it much easier to obtain their sight picture, focus on their target, and nail the shot when they have a complete field of view and can see more of the surroundings of their target.  Field of view denotes how big the picture is via the scope. Although it is affected by magnification, yet, two scopes can have similar magnification but different fields of view.

Light Transmission

The amount of light that travels from the exit pupil into the eye socket is measured as light transmission. A few factors contribute to this, but the majority of them are the quality of the lens elements along with the size of the coatings and objective lens diameter.

Light transmission decreases as magnification increases, and you may need to adjust the eye relief if you want to shoot at the higher end of your rifle scopes’ magnification range. Depending on the type of shooting, this is a crucial issue. If you’re just going to the range during the day, a scope with little brightness is not a big concern.

However, if you’re shooting at dawn/dusk or in other low-light settings, being able to view the entire field clearly is a great move and should be at the top of the priority list. Is eye relief necessary? Yes, but so are many other things.

Image Quality

High magnification bends a lot of light and might make it difficult to see clearly. You’ve undoubtedly seen this before if you use binoculars or wear glasses. The image might become distorted, especially at the edge. High magnification can reduce eye relief. You should plan to adjust your posture based on the scope’s strength, especially if it is long range shooting. This can also have an impact on image clarity concerns such as chromatic aberration, color accuracy, and so on.

A long eye relief scope is ideal for heavy calibers with high recoil. Although you cannot alter the eye relief since it is the distance your eye must be from the ocular lens, you can however still measure the eye relief and adjust the location of the rifle scope lens on the gun. Adjusting the rings is a simple procedure.