What Are Dielectric Prism Coatings on Binoculars?

Spread the love

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

Prism has been an integral part of all the binoculars and other optical tools. However, the manufacturers have tried their best to get maximum output and performance from the prism by applying coatings on them. One of those coatings is dielectric coating.

But what is dielectric coating in the binoculars? Actually, the thin layer of dielectric material (Silicon dioxide and titanium dioxide is applied on the surface of the prism to increase the transmission of light and reduce the reflection. This thin layer is called dielectric coating which helps in enhancing the performance of the binoculars.

Almost all the binoculars users usually don’t have much information about the interior parts and their role. Don’t worry, I will keep things very simple so that it gets easier for you to understand.

Related Article: What Is BAK-4 Prism in Binoculars?

Purpose of Dielectric Coatings on the Prism of Binoculars

As you know, the role of prisms is very important in binoculars. But the dielectric further uplifts the standard and the performance of those prisms. The thin layer of dielectric material is applied to the prism to increase the transmission of light. 

When the objective lens captures the light, then it focuses all the light on the prism. The prism reorients the image, but in the process, some amount of light gets lost which certainly affects the visual quality. But the manufacturers have found a solution.

To minimize the loss of light, the manufacturers apply a thin layer of dielectric material on the surface of the prism. These coatings are very effective in reducing internal reflection and increasing the transmission of light.

As you know, when the light passes through the glass of the prism, some amount of light gets lost. However, the dielectric coatings reduce the reflection of light so that a minimal amount of light gets lost. They also increase the transmission so that the user gets maximum light at the eyepiece.

When there is no loss of light, it means more light reaches the eyepiece, and the user ends up getting brighter visuals without any chromatic aberration. This is why the manufacturers use the dielectric coating in the binoculars as they enhance the performance of the binoculars.

Efficiency of Dielectric Coatings on the Prism

Well, the efficiency of the dielectric coating depends on the dielectric material, and the thickness of the coatings. However, a high-quality coating can improve light transmission up to above 90%.

The performance of the dielectric coating also depends on the manufacturer. For example, almost all the Chinese manufacturers focus on reducing the price of their products so they use cheap coating which does not improve the performance of the binos significantly.

On the other hand, the brands that work in the USA usually love to provide more value and sell their products at higher prices. So, they use high-quality dielectric coatings to ensure that the user gets the best performance from the binoculars.

The thickness of the coating also plays a crucial role in the performance. Keep in mind that the manufacturer uses specific thicknesses depending upon a particular range of wavelengths. In usual cases, the dielectric coating enhances the transmission of light above 90%.

Also Read:  Why Are Prisms Used in Binoculars?

Are Binoculars with Dielectric Coating Expensive?

Yes, dielectric materials are usually expensive, so applying the thin coats on the prism is surely an expensive process and it adds to the overall price of the binoculars. You will need a handsome budget to buy a binocular with dielectric coatings.

It is important to note that different people have different spending powers. This is why binoculars with different prices are available in the market. However, the price has a massive impact on the performance of the binoculars. 

For example, expensive binoculars with dielectric coating will provide you with brighter, shaper visuals with ideal optical performance. But the cost of these binoculars would be on the higher side. If you have a tight budget, it would not be easy for you to afford these binos.

On the other hand, some binos don’t have such coatings on the prism, so their optical performance is massively compromised. But these binoculars are cheap and you will be able to afford them quite easily. As long as the binos with dielectric coating are concerned, they are super expensive.

Are Binoculars with Dielectric Coating Worth it?

Yes, I truly believe that the binoculars with dielectric coating are worth your attention and investment as they uplift the optical performance of the binoculars. But if you are someone who does not use binos much, then you can overlook this feature.

Keep in mind that the dielectric coating in the binoculars improves the transmission of light which ensures that you will get brighter visuals. This feature is also helpful in giving you decent visuals in lowlight conditions such as in cloudy weather, before dawn, or after dusk.


There is no doubt that the dielectric coating plays an important role in giving you brighter and sharper visuals. They improve the transmission of light and ensure that you will see brighter images even in low-light conditions. If you are considering buying binoculars, I highly recommend you try binoculars with dielectric coating and enjoy the crisp visuals.

Spread the love

Leave a Comment