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How to Focus Binoculars Correctly: Diopter Adjustment Guide

How to Focus Binoculars Correctly

Learning how to focus binoculars?

You’ve probably seen a pair of binoculars lying around your house. After all, binoculars are a perfect tool for stargazing, hiking, and sports-watching.

But if you’re not using it properly, instead of seeing a clear image of an object, you might end up seeing blurred-out images instead.

As it turns out, there’s a RIGHT WAY on how to focus your binoculars!

And we’ve come up with this review to show all you newbies out there to know how to focus a pair over any distance!

Steps on How to Adjust Your Binoculars

Let’s prepare to focus and calibrate your binoculars.

Divided into just two simple steps, there’s no way you’re ever going to have to tolerate seeing a blurry focus and view anymore.

To get started, bring your binoculars up to your eyes.

Step 1: Focus the Central Knob

Step 1

Also referred to as center focus, this general step sets up the foundation of your view.

  • Find a stationary object. Something at a faraway distance would be great for central focusing.
  • Adjust the central knob until you see the clearest and sharpest image in both of your eyes.

Step 2: Calibrate the Diopter

Step 2

We will be breaking this step into four categories for easier retention:

  1. Cloaking the lens
  2. Through the left eyepiece
  3. Through the right eyepiece
  4. And uncovering both lenses

But before we go into the specific step-by-step instructions, make sure that you set the diopter to zero or move it to the center.

Cloaking the Lens

This part of binocular calibration is the first step in making the general adjustments more specific.

Cloaking the lens simply paints the idea of seeing the world through one eye only.

  • Cover the front of the lens on the barrel with the diopter scale. That is to say, the one on the right! You can cover the front with a lens cap or simply tape it up.
  • Read the central knob to make sure that your left eye sees a center focus image at an interpupillary distance.

Through the Left Eyepiece

At this point, remember to keep both your eyes OPEN, even if we’re just focusing on one. This is since each eye has different eye strengths.

Squinting can lead to a distorted reality because it alters the viewing angle of your eyes and focus system.

Be sure you don’t close your left eye.

  • Look through the binoculars’ focus system with your left eye using the left barrel.
  • Move the diopter’s ring left or right to ensure that your left eye sees an even clearer and sharper image than before.

Through the Right Eyepiece

This reiterates the previous section, but now we do it for the other eye. Remember, do not keep any eye shut!

And as much as possible, do not put your binoculars down. This is to ensure that all things remain constant throughout the binocular and diopter calibration process.

Follow these tips for easy adjustment:

  • Uncover the right lens and cloak the left one the same way you did a while ago.
  • You should now be looking through the binoculars with your right eye using the right barrel.
  • Adjust the ring left or right to make sure that your right eye sees an even clearer and sharper view than before.

Uncloaking Both Lenses

This is a mere reiteration of the binocular cloaking of lenses in the previous section.

  • Uncover the left lens. Make sure both lenses remain uncovered.
  • You should now be looking through the binoculars with both eyes.
  • The sharpest and clearest view should now be visible to you.

After accomplishing each step, you shouldn’t strain your eyes at all. Your vision should be clear, and you should be comfortable enjoying the view.

The viewing experience should be great!

Otherwise, you may have done something wrong. Try to check if you’ve been squinting your eyes while accomplishing Through the Left and Right Eyepieces. Or maybe you could also adjust your eyecups.

TAKE NOTE: In most binoculars, accidental knob and diopter ring adjustments could happen.

Hopefully, that won’t be a problem when you set your own diopter adjustment wheel setting since you already know how to central focus binoculars and calibrate them to your liking!

Moreover, calibrating and focusing binoculars would only be necessary if your eyesight changes or you lend your pair to somebody else.

Vision is specific to different people! That’s why the way you use your center focus knob matters.

Focusing vs. Calibrating Binoculars

People often confuse the terms focus and calibration with each other.

But trust us when we say that they are different from each other!

Simply, when calibrating, whether it be for your monocular or binoculars, you are making a series of small adjustments to have your device better focus on a subject.

But for you to appreciate this differentiation, you first have to understand the anatomy of your binoculars.

Central Knob

Central Knob

This one is hard to miss. This is the bridge between the two barrels of your binoculars!

Sometimes, the knob is called the ” central focusing wheel” to refer to its functional use. Adjusting this knob allows you to focus binoculars through your barrels.

Focusing isn’t that easy, though.

There would be times when the most focused view is still too blurry for your liking. When this happens, know that your pair of binoculars isn’t defective.

You simply haven’t calibrated it yet!

Diopter Ring

Parts of binoculars

These rings are the real binocular GAME-CHANGERS!

Specific to each barrel, the ring calibrates your lenses so that you can see a clear and crisp image. Or to focus on one object, if that helps differentiate between the two!

To understand why this is so, you have to remember that our left and right eyes are independent of each other.

This makes diopter adjustment essential to address nearsightedness or any visual acuity difference in eyesight in people.

Also, the diopter may be found on the central knob. Should this be the case, it is safe to assume that it affects the right barrel.

Despite their differences in diopter location, this guide holds true for each type.

You will learn more about how to use the diopter and the diopter settings later in this guide.

Essentially, we are learning about how to focus binoculars on a certain object to account for the betterment of our own vision.

Also, think of the central knob as the general step because the specifics are only provided after setting your diopter adjustment ring.

If you’ve made it this far, then you more or less have a good grasp of the anatomy of your pair of binoculars.

A Must-Have: Lockable Binos

Must Have

To avoid focus and diopter readjustments, you should consider getting yourself one of these.

Lockable binoculars have the special feature of having a lockable diopter adjustment ring.

As the name suggests, this has the advantage of setting your diopters in place. You don’t have to worry about accidentally moving the rings while you work.

And no matter the added locking mechanism, the same process in focusing binoculars still applies.

The one difference is that you have to lock the diopter adjustment ring after going through each side.

These diopters sound awesome, right? It saves you lots of time, too.

Lockable diopter adjustment rings are usually featured in binoculars with diopters found on the center knob, as described in the first half of this article.

Final Thoughts

Final Thoughts

Knowing how to focus binoculars on an object is important when you’re out there on the field.

With this knowledge, go find your own adventure and experiment with your binoculars! You might just surprise your eyes with just how beautiful your field of view is.

Indeed, you literally see the world from another perspective. The viewing experience should be great.

You can also check out our article on your must-have hunting gear to get you ready for a day outdoors.



July 6, 2022 - Minor content edits
May 30, 2022 - Added 1 new article link
September 8, 2021 - Reviewed and updated article links

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