Is the Objective Lens of a Binocular Convex or Concave?

By Richard

This post may contain affiliate links which means I may receive a small commission for purchases made through the links. Read More

Binos, no matter what purpose you use for, provide excellent help and make you able to see distant objects in full detail.  But many people don’t have much knowledge about the technical aspects of this wonderful aspect. 

So, in this blog post, I will take into depth exploring the anatomy of binoculars and let you know what kind of lens binoculars use. Before going into the details, here is a brief answer for those who are in a hurry.

Most binoculars use convex lenses in their objective lens. The reason is that the usage of these lenses the binoculars to capture more light and redirect it to the eyepiece to give users brighter visuals

It was a brief introduction, but I have a lot more information to share with you. What are objective lenses and why do they consist of convex lenses? If you want to know, stay connected till the last word.

Related Article: How Do Binoculars Work?

What is an Objective Lens in Binoculars?

Before we go into details, you must know the basic information. Actually, the objective lens is a glassy part located at the front of every binocular and it is used to capture the light present in the environment. 

Have you ever used binoculars? If you have used it you will have the idea that a binocular has two barrels through which light enters into the binoculars. At the front of these barrels, two lenses are present, which are called objective lenses.

Note: The objective lens is usually represented by its diameter, expressed in millimeters.

Role of the Objective Lens in Binoculars

I’m sure that you now better know how about the objective lens of binoculars. Let’s talk about its role and functionality. This lens plays a crucial role in determining the quality of the image seen through the binoculars. 

Actually, objective lenses capture the sunlight present in the surroundings. When you use binoculars having a very smaller sized objective lens, then it captures very less light and gives you a very dimmish image having very low quality. 

On the other hand, when you use a binocular with a bigger-sized objective lens then it captures more light from surroundings and it gives you better visual quality. In short, the objective lens is used to capture the light from the surroundings and give you a better image with excellent brightness.

Also Read: Are image stabilized binoculars worth it?

Is the Objective Lens of a Binocular Convex or Concave?

The objective lens of all the binoculars is always convex. If you don’t know what a convex lens is, it is a lens that is thicker at the middle or center and its edges are relatively thinner. It usually bulges outwards. The curved surface of the convex lens helps to gather light from the surroundings. Why binoculars use convex lenses will be explained in the next headings.

Why is a Convex Lens Used in Binoculars?

A convex lens is used in binoculars for several reasons. These lenses are good in many ways and the reasons of their usage are listed below;

  • These lenses allow for a wide field of view, making it easier to locate objects in the distance.
  • The curved surface of the convex lenses helps to reduce chromatic aberrations.
  • Its curved surface also helps the binoculars to capture more light and give you brighter visuals.


In short, all modern binoculars use the convex lens in their objective lens as it provides many benefits. The important help that convex lens offer is the capturing of light. Keep in mind that when your binoculars capture more light, you get better visuals. Let me say that a convex lens indirectly improves your visual quality. I hope that this guide will be helpful to you.

Leave a Comment