How to Focus Binoculars with Diopter in 6 Simple Steps

  • By: Michaela King

Binoculars are fairly simple to use and that is one of the reasons why they are so popular. To use binoculars, you don’t need to be an expert.

Even a beginner can enjoy the view offered by binoculars without any complications. But sometimes it happens that the focus and calibration of a binocular seem to be off and the image quality is not up to the mark.

Many people don’t have any clue about how to focus binoculars with diopters. For clear and synchronized view binoculars need to be adjusted using binocular diopters placed around one of the ocular lenses in a shape of ring usually.

Some people think that diopter adjustment is a complicated task which is not true. In fact, it is a fairly simple process and once you understand the process, it takes a few minutes to adjust both lenses.

In this article, you are going to learn how to focus binoculars with diopter easily so that you can get the maximum out of your binoculars.

How to Focus Binoculars with Diopter Video Guide

How to get crystal clear focus with your binoculars

Central Knob

Almost every binocular include a central control knob that is situated right at the centre of both the lenses. It is hard to miss a central knob.

A central knob or a flywheel is used to focus both the lenses on any view or object you wish to see. Using central knob you can move the lenses according to your visual needs.

Also read my complete guide on choosing binoculars for beginners

What is Diopter Ring?

Usually, people don’t know that their binoculars have an option to calibrate the lenses. Diopter knob is in the form of ring wrapped around the right lens usually. Look for the +, – sign around the lens to spot your diopter ring easily.

Our both eyes have different viewing range which is why adjusting binoculars according to one’s own viewing capacity is very important.

And for those people who have nearsightedness or different eyesight in both eyes, adjusting focus according to their vision is very crucial so they can get maximum clarity out of their binoculars.

While central knob can be used to set focus on both lenses, it doesn’t calibrate the binoculars according to the one’s viewing capacity.

For that diopter, rings are used and you need to know how to focus binoculars with the diopter.

Follow this simple step by step guide to easily calibrate your binoculars.

Step 1 – Find a Stationary Object

Find a stationary object like a tree, a pole and focus both the lenses on the object using the central focusing wheel until the image in both eyes is sharp and clear.

Step 2 – Adjust Diopter Ring 

Find the diopter adjustment ring which is usually located at right ocular or in some cases around the central wheel. Set the ring to zero or move it to the centre.

Step 3 – Cloak the Lens

Cloak the lens that has a diopter ring which is usually the right one. You can cover it with a lens cap or simply tape it up so no light can pass through it.

Step 4 – Use One Eyepiece

Look through binoculars with your left eye using the left barrel. Remember to keep both eyes open because squinting can totally alter your viewing angle which can lead to unclear viewing. Now focus on the object that you first spotted using the central knob. Adjust the knob to get the clearest view possible for your eye.

Step 5 – Uncover the Covered Lens

Uncover the right lens and cloak the left one similarly. Place your right hand on diopter ring and place your right eye on right barrel. Move the diopter ring left or right to make the image as sharp as possible for that eye.

Step 6 – Uncover both Lenses

Uncover both lenses and look through binoculars with both eyes. View through calibrated binoculars feels clear and sharp as well as comfortable for eyes.

Some binoculars have diopter rings located on the central knob. In that case, the method is the same. Just follow the above guide closely for an enhanced view.

Once you have calibrated your binoculars using diopter adjustment ring, you don’t need to set it again unless your eyesight changes or you lend your binoculars to someone who has different eye range than you.

Lockable Diopter Rings

Some high end and expensive binoculars are equipped with a diopter locking system. By locking the diopter, the setting cannot be turned or moved accidentally.


We hope that by following this guide, you have come to understand how to focus binoculars with diopter.

Have a great view, folks!

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