How to Focus Binoculars Correctly

How to Focus Binoculars Correctly?

A hunting binoculars are not the same binoculars that you used to play with when you were just a kid. But just like a toy, they are fun and exciting to use, especially if you know how to use them right. Knowing how to focus binoculars is part of learning how to use them.

This post will go through how to adjust your binoculars and the various types of focus systems available. We will also discuss factors that influence focusing like eye relief, exit pupil, and IPD distances. Some of the consumer’s questions were also answered in this article. By the end of this post, you will know how to focus on the gadget correctly.

When Do I Need to Focus My Binoculars?


Every new binoculars require focusing. Before you can use them on hunting or birdwatching, you need to make sure that you can accurately see the object on target. If not, you might not be able to get your target. Some people are having a hard time focusing their binoculars while others are not. The best thing to do is to familiarize yourself with the different parts of the binoculars and their functions so that you can focus your binoculars accurately.

Why can’t I focus my binoculars?


Some binoculars don’t have diopters, particularly the cheap models, do not settle for these types as you will never get a sharp image from them. Our eyes are not the same, no matter how we think they are. You will always find some difference between the right and left eye. One reason for having a hard time focusing your binoculars is that the diopter was not correctly calibrated. Make sure you have followed the steps on calibrating the diopter before you try to focus your binoculars.

Factors that influence focusing


Eye Relief

This refers to the distance between the end surface of the eyepiece lenses and the eye at which the complete field of vision is seen without vignetting using binoculars. If the eye relief distance is long, even those who wear glasses will not have a problem using binoculars.

Exit Pupil

When viewed from around 30 cm away from the eyepiece lenses, the pupil of binoculars looks like a brilliant circle. This is referred to as the “exit pupil diameter.” The exit pupil diameter is determined by dividing the effective diameter of the objective lens (mm) by the magnification (x), and the relative brightness of a pair of binoculars is represented in terms of “exit pupil diameter (mm)”2. The brighter the picture in the binoculars, the greater the exit pupil diameter.

IPD, or Interpupillary Distance

The distance between the pupils of both eyes is measured as the interpupillary distance. Adults have an average spacing of about 65 mm. The binoculars’ interpupillary distance may be changed by sliding both parts of the binoculars outwards or inwards.

Steps on How to Focus Binoculars


Selecting the proper and compelling binocular is critical. Binoculars are often used for a variety of purposes. As a result, manufacturers designed binoculars based on what it is used for. So, you have to consider your purpose for buying the binoculars. Then, find and select the most accurate binoculars for your needs. Once you get hold of your binoculars, you can focus them. Follow the steps below on focusing the binoculars.

Step #1 Focus the Binoculars on an Object

Look at a stationary object with a distance of around 30–40 feet (9.1–12.2 m) away. If the image is fuzzy when viewed in the binoculars, the focus has to be adjusted.

Even though the object is clear, you should calibrate your binoculars to get an even sharper image.

Step #2 Cover the Right Lens

Cover the binoculars’ right lens and focus with your left eye. To cover the right lens, place your palm over it. If the picture is fuzzy when you look through your binoculars with your left eye, you need to adjust the focusing ring in the middle of the binoculars.

The focusing ring focuses on your primary target, while the diopter on the right eyepiece adjusts for variations between your left and right eyes.

Step #3 Adjust the Focusing Ring

The focusing ring in the middle of the binoculars should be adjusted. The focusing ring is the wheel located in the middle of your binoculars, between the two barrels. Rotate the ring right and left until the object in your left eye is clear.

Remove your hand from the lens once you’ve finished focusing the left eyepiece.

Step #4 Cover the Left Lens

Cover the left lens and focus using your right eye. Close or cover your left eye and concentrate on the image using only your right eye. If the image is blurry, you should adjust the diopter on the right eyepiece.

If your vision is the same in both eyes, you may not need to change the diopter on the right eyepiece.

Step #5 Adjust the Diopter on the Right Eyepiece

The diopter on the right eyepiece should be adjusted. The diopter is the eyepiece’s wheel. This compensates for variations in vision in each eye. To adjust the diopter, check the object if you can see the object clearly with your right eye as you keep the left lens covered. If not, continue rotating the diopter until you can see the object well.

Calibration of your binoculars will be easier if you focus on one eye at a time.

Step #6 Check the Binoculars with Both Eyes

Look into the binoculars with both eyes. You should feel comfortable doing this, and the item should be in focus. The diopter on most binoculars will be marked. In case you need to adjust them again, take note of where the diopters are.

Keep in mind the following:

  • You shouldn’t have to adjust the calibration when you get it right the first time.
  • If the picture is still fuzzy, you may need to adjust the diopter in the binoculars’ center.


Frequently Asked Questions


a) What is diopter focus?

The diopter measures the refractive power of lenses on binoculars. It is usually measured in millimeters, and the higher the diopter, the stronger the lens and the more the correction required to focus our vision.

The diopter is used to focus the object that we perceive when we look through the lens. Others get confused and think the diopter and the focus wheel are mixed up. While they both aid in adjusting our image’s focus, they do it in very distinct ways. There are two types of adjustable diopters on binoculars: central focusing and individual focusing.

b) Does diopter affect focus?

Yes, the diopter affects focus. The diopter is an adjustment ring that adjusts the focus of one barrel independently of the other and is thus used to correct any discrepancies on your right and left eyes. The diopter is usually found on your optics‘ right or left barrel, close to the eyepiece, labelled – 0 +.

Take note some binoculars have a diopter in front of or behind the central focusing wheel built-in or in a separate ring.

c) How do you get crystal clear focus with binoculars?

To get a clear focus with your binoculars, you need to adjust barrels, eyecups and set the diopter correctly. In adjusting the barrels, make sure that the binocular barrels are properly lined up with your eyes. It will help you get your sight on a single image when you see thru your lenses.

Next, you need to adjust the eyecups. This will depend on whether you are wearing or not eyeglasses. For those who wear glasses, it is vital to keep the eyecups down. If you prefer using your binoculars without the eyeglasses, you need to roll up the eyecups. It will have fewer distractions and easy to control time.

Then you need to set the diopter by following the steps above. Make sure you set the diopter correctly to get a crystal clear focus.

Final Thoughts


Your binoculars are useless if you do not focus them properly. Knowing how to focus binoculars is part of learning how to use them. Factors that influence focusing include eye relief, exit pupil, and IPD distances. Binoculars’ interpapillary distance may be changed by sliding both parts outwards or inwards. The focusing ring is the wheel located in the middle of your binoculars, between the two barrels. The diopter on the right eyepiece adjusts for variations in vision between your left and right eyes.

Some people are having a hard time focusing their binoculars. The diopter is used to focus the object that we perceive when we look through the lens. Make sure you follow the steps on focusing your binoculars. If you have questions or want to share your ideas about the topic, feel free to comment below.

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