Why Are Binoculars Filled With Nitrogen? Argon VS Nitrogen Gas Purging

By Richard

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Almost all of us don’t bother about weather conditions and feel happy to carry our binoculars with us. We don’t stop using them during the rain.  Have you ever wondered why rain or moisture does not damage your binocular lenses? The protection of your binoculars is possible only due to insert gasses. In this guide we’ll talk about the binoculars’ protective gasses and answer your query: Why are binoculars filled with nitrogen?

Why are binoculars filled with nitrogen? Nitrogen and other inert gasses are filled in the binoculars for purging purposes. When moisture or water goes inside then these dry gasses act in such a way that they remove all the moisture and make binos safe from harsh weather and the environment. Only one gas either nitrogen or argon can be filled in one binocular.

It was a short answer to give a kind of summary of this article. But we have got something more detailed for you. Keep reading!

Also Read: Can You Use Binoculars with Contact Lenses?

How Is Nitrogen or argon gas Purged Inside Binoculars?

There are many glasses that are present in our environment which is very beneficial. From those glasses, nitrogen dioxide and argon are used for purging purposes, making the binoculars protected against moisture and water. 

At very low pressure, these glasses are filled inside the binoculars and then eyecups are sealed completely to avoid any escape of these glasses. Keep one thing in your mind one gas either nitrogen or argon can be filled in one binoculars. You can use both gasses in a single binocular. 

Also Read: Why Are Binoculars Not Allowed in Egypt?

When dry gas either nitrogen or argon is filled then all the rubber sealings are closed. Now, the moisture comes and tries to enter inside, then the dry gas immediately performs its functions and removes the moisture and any other impurities. 

When the purging process is complete, then you carry your binoculars in the water while bathing or in the rain while having fun in rainy weather. Your optics will be protected against water and you won’t have to be worried about their protections. 

Point to Ponder: Gas that is filled in binoculars must be inert and should not be reactive to any other gas or chemical.

What Are The Benefits Of Nitrogen?

Nitrogen is a dry gas that is used for the purging of binoculars. It is filled in them at very low pressure to make binos resistant to moisture and other impurities. Nitrogen gas purging has the following advantages

  • Nitrogen purging makes your binoculars water and moisture-proof and you will be able to use them in rain or watery places.
  • Not only moisture, but nitrogen gas also protects optics from other impurities like dust, debris, and other contaminants.
  • When your binoculars are mishandled and are not working due to any reason then you have to store them in rice or any other moisture repellent places where chances are high that fungus will attack your binoculars. So the nitrogen gas also marks your dinos safe from fungus and doesn’t allow it to contaminate the inside of your binoculars. 
  • Sometimes you go out to places where water and moisture is common. No one likes to witness the beauty of nature and you won’t like to stop using binos because of moisture. So nitrogen gas helps you enjoy the scenes in moist places.

Are Non-Nitrogen-Filled Binoculars Worth Your Money?

No, not at all.

The binoculars that are not purged with nitrogen or any other dry gas do not deserve to be shopped. Such binoculars are a headache as you will have to take extra care of them and let them not get moisture or wet. We don’t recommend buying binos without gas purging.

Also Read: Why Do Binoculars Have Red Lenses?

What is better binocular filling: Nitrogen or Argon?

Argon is certainly premium and very least reactive to any other gasses. The purging of argon gas makes it literally impossible for moisture to go or stay inside the binoculars to fog up the lenses. But argon being premium gas is more expensive and those binos that come with argon purging are very expensive. 

Note: Binos that are argon gas purging is perfect to be used in heavy rain and you won’t have to be worried even if you put them in a water tub for half an hour.

In contrast, nitrogen gas is not very premium but does a decent job to make your binoculars secure from moisture. With nitrogen purging, you will have to take a bit of care. Nitrogen purging is less expensive as compared to argon gas.

What is better binocular filling: Argon gas purging is definitely a better way to go as you will be 100% sure about the security of your binos. Spending a little more on argon gas will give you peace of mind.


We buy binoculars for outdoor activities. Weather and moisture both are not out of control. Your outdoor fun can be affected by rain or moisture if your binos are well protected by dry gas purging. 

No matter whether you choose nitrogen or Argon, your optics must be purged to give a kind of confidence to go out and have fun. Buying optics that lack gas purging is like a waste of money and time. 

In the end, our aim was to educate you about nitrogen gas filling and why it is important for the protection of binoculars from rain, moisture, debris, dust, and other contaminants. We hope that our efforts will bring value to your life.

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