What does binocular eye relief mean?
I’ll venture a guess that you want to get a set of binoculars but are unsure of what some of the features mean.
So, you’re now debating whether or not you ought to look for eye relief. You actually have no idea what it even is, though!
I can identify with it.
This is the reason I wrote a guide specifically about eye relief in binoculars.
We will talk about what eye relief is, whether it’s necessary, and what to look for if it is.
What is eye relief in binoculars?
You can only see clearly via a pair of binoculars if your eye is at the right distance from the eyepiece.
This separation is referred to as eye relief.
It is the greatest distance that your eyes can be from the oculars, which are the tiny lenses you use to perceive the world.
Imagine a hunter using a firearm. Take note of the space they leave between their eye and the scope’s eyepiece.
They require a long eye relief so they can see the entire field of view, as well as a buffer zone for gun recoil.
Birdwatchers are a unique group. The binoculars will be held in close proximity to your eye.
The gap between your pupil and ocular lens when the eye cups are resting on your face is known as the eye relief.
How important is eye relief in binoculars?
Unless you use glasses, eye relief is typically not a problem for binocular users.
Although if you have particularly deep-set eyes, that can also be a problem.
You can’t get your eye as near to the lens as you would like because of your spectacles.
Therefore, if you wear glasses, you are at a disadvantage because they limit your ability to get the eye cups near.
That gives you two issues:
Restrictions on Field of View
2. More perimetric light
Now let’s examine each problem.
Eye Relief and field of view
Your eye will see a fantastic image when it is at the proper distance from the lens.
Beyond this point, your field of vision starts to become more limited. In turn, you can lose out on spotting a bird because you won’t see all of the image through the binoculars.
Therefore, every time you use your binoculars, regardless of how amazing they are, you will be let down.
Eye Relief and Peripheral Light
When you hold your eye cups close together, peripheral light is the faint amount of light you can see at the side of your eyes.
You’ll see less peripheral light the closer you can get the cusp to your eyes. The quantity of peripheral light and vision you can see using binoculars is increased when wearing glasses.
Although you can’t completely avoid this problem when you wear glasses, you can lessen its effects.
When using binoculars while wearing glasses, you can reduce this problem by adjusting the eye relief. With fewer outside distractions, you’ll be better able to concentrate.
Should you wear glasses with binoculars?
Consequently, you may be considering whether it makes sense to quit wearing your spectacles when using binoculars.
You won’t need your binoculars if you solely use your glasses for magnification.
The issue with it is if you were given glasses to correct vision issues like astigmatism. Without your glasses, you’ll likely have poor eyesight.
But if you must keep your spectacles, don’t worry. Designers of binoculars have come up with a smart solution to this problem.
Eye Relief Feature in Binoculars
So, as you might have guessed, the purpose of the eye relief feature on glasses is to allow binoculars to be adjusted for people who wear spectacles.
An eye relief feature will be present on all high-quality binoculars. If they don’t, I’d wonder about the binoculars’ quality.
Those who don’t wear glasses won’t be impacted by the eye relief feature, but it might improve the comfort of the eye cup.
Examining the two categories of eye relief
Short Eye Relief in Binoculars
Anything with a short eye relief of less than 13mm.
Short eye relief is more of a feature seen on hunting scopes than on scopes used for birdwatching.
Binoculars with short eye relief are only appropriate for people who don’t wear glasses.
When purchasing binoculars, you should take eye relief into consideration if you wear spectacles. Then you must refrain from picking any model with a limited eye relief specification.
This is due to the fact that even the thinnest of glasses will require eye relief of more than 13mm. And ultimately, a portion of your field of view will always be lost.
Long Eye Relief In binoculars
Any eye relief length over 20mm is considered long.
It is necessary for those who wear glasses to look for binoculars with long eye relief.
This is due to the fact that binoculars with a lengthy eye relief may be adjusted to fit nearly all types of glasses, regardless of their thickness.
The difference between seeing the entire field of vision and missing something will depend on your ability to adjust the binoculars just a little bit more.
The last thing you want is to not be able to use your binoculars to their best potential after spending hundreds or even thousands of dollars on them.
What is a good eye relief for glasses wearers?
You may have noticed that binoculars’ eye relief can range from 5 to 24 mm.
If you use spectacles, binoculars with an eye relief of at least 16mm are perfect.
To be safe, I would advise looking for a spec of about 18 to 19mm.
The majority of people who wear glasses can safely use binoculars with eye relief of 20mm or more. The problem is that these models are frequently pricy high-end alternatives.
In reality, it will depend on how thick your glasses are.
If the eye relief on a pair of binoculars is inadequate, you might be able to gain extra room by turning the cushioning back or pulling the eye cups in.
Is Eye Relief the same as exit pupil?
The eye relief and exit pupil are not the same dimensions.
The size of the light exit pupil is the light leaving the lens. When closed, the image will appear brighter if this number is near to the size of your pupil. A bigger exit pupil will therefore always provide brighter images than a smaller exit pupil.
This is computed by dividing the objective lens by the magnification, and it is expressed in millimeters (mm). Therefore, the eye relief of an 832 binocular will be 32/8 = 4mm.
Both during the day and at night, your pupil size fluctuates. If you use your binoculars in poor light, a wider exit pupil will be beneficial for bird watching.
The eye relief for binoculars is determined by the exit pupil, which causes misunderstanding in this area. Additionally, some manufacturers, like Zeiss, would specify the exit pupil diameter and the exit pupil distance as the eye relief.
The point at which the exit pupil size reaches your eye is what determines the precise eye relief distance.
Are 8x or 10x magnification binoculars better for eye relief?
Magnification alters eye relief.
This is due to how magnification alters the exit pupil. Therefore, a 10x binocular will provide a smaller exit pupil size than an 8x (based on the calculation above).
Longer eye relief distances are possible with larger exit pupil sizes.
Any binocular model’s 8x version will provide more eye relief than the 10x version, as you’ll observe. Typically, there is a 1-3mm difference here.
Let’s look at a few instances:
Canon EOS 1D X
While the 1042 version provides 18mm of eye relief, the 842 version provides 19.5mm.
a Diamondback Vortex
Both the 832 and 1032 versions provide 14mm and 16mm of eye relief, respectively.
Endeavor Vanguard ED
Both the 842 and the 1042 models provide 16.5mm of eye relief.
These examples demonstrate that there is no set magnification that must be used to provide eye relief. However, an 8x binocular will be more effective in helping you achieve a larger eye relief.
The choice of binocular magnification is entirely subjective. If you wear glasses and prefer a 10x magnification, you may need to do a little more research.
To Save For Later
Can I adjust the eye relief power in binoculars?
Yes is the clear-cut answer
The eye cups of high-quality binoculars should be adjustable. Even more eye cup positions might be available from some brands. To get closer to the lens, you might even be able to take off the padded cups.
Fully retracted
An eye cup that has been pushed all the way in is fully retracted.
If you wear glasses, you should use this one because it will help shorten the eye relief and bring your spectacles closer to the ocular lens.
If you have deep-set eyes, you should choose this option because it may be more comfortable for your eyes.
Simply use caution when handling the lens in this position because it is more vulnerable to dirt and lens damage.
Fully Extended
The maximum distance that an eye cup can be pulled out will be reached.
Only people with deep-set eyes or those who don’t wear glasses should truly be in this environment.
You can improve your ability to focus by reducing peripheral light by fully extending the eye cup.
The extent of the eye cup’s extension could somewhat narrow your field of vision.
Also, be warned that extending the lens all the way may cause your lens to fog up. Warm air that has been trapped in the eye relief area is the cause of this.
Middle extension
Between fully stretched and totally retracted is an intermediate extension.
If you don’t wear glasses, this is the perfect compromise. Even if you use thin glasses, this environment can be appropriate for you.
By doing so, you obtain the advantages of lessening peripheral light and lowering the possibility of lens damage.
Eye relief Explained
6 Best Binoculars For Eye Relief
1. Zeiss Victory SF
19mm of eye relief are provided by this 832 version.
2. Vanguard Endeavor ED
19mm of eye relief are provided by the 8x42mm version.
3. Nikon Monarch 5
19.5mm of eye relief is offered by the 842 version.
4. Nikon PROSTAFF 3S
20.2mm of eye relief are provided by the 842 version.
5. Vortex Viper HD
20mm of eye relief is provided by the 842 binoculars.
6. Pentax DCF ED
22mm of eye relief are provided by the 843 version.
Final thoughts
When purchasing binoculars, you should be aware of the eye relief feature.
especially if your eyes are deep set or if you wear spectacles.
Finding a pair of binoculars with the proper eye relief can determine whether you get a decent view or miss out on some of the scene.
You should be able to select a nice set of binoculars with enough eye relief to get a fantastic view of the birds by utilizing the advice in this post.
If you use glasses, please tell me which binocular I should get or which one I should stay away from in the comments section below.
FAQ
What is a good amount of eye relief?
Make sure you buy a scope with at least 3.5 inches of eye relief to keep things simple. Go for even greater eye comfort if your weapon has a strong recoil. Having said that, check out the entire selection of top-notch riflescopes from Bushnell if you’re seeking for cutting-edge optics with exceptional eye relief.
What is eye relief distance on binoculars?
Eye relief is the distance between the eyepiece’s outer lens surface and the point at which the exit pupil forms (eyepoint). From the eyepoint, using binoculars, you can see the entire field of view without vignetting.
How important is eye relief in binoculars?
They only see the center of the image if the eye relief in the binoculars is too short. The nice stuff that’s around the margins is hidden. The problem is that every binocular is designed to have an optimal distance between your eye and the eyepiece glass.
How is binocular eye relief measured?
Eye relief can be expressed in millimeters (mm) or inches (in), and it varies according on the model, the manufacturer, and the kind of optic. For instance, a rifle scope may have long eye relief at 4 inches whereas a binocular’s acceptable eye relief is 15 mm.
What is considered good eye relief?
Eye relief is the distance your eye has to be from the rear lens in order to see the entire scene. A fixed-power scope typically has a diameter of 3 1/2 inches. For the majority of variables, you’ll start out there at lesser power and roughly 2 1/2 inches at maximum magnification.