Fogproof | Optics Trade Debates

  • Polona 


Fogging occurs when optics experience a rapid change of temperature. If there’s air on the inside of the optics that contains moisture, internal condensation will occur. The moisture starts forming small fog droplets inside the optics. So if the optics aren’t fogproof, they will not be usable in winter or in other situations where they would encounter substantial temperature differences.

Fogproof optics contain no moisture that could cause fogging. This is usually achieved by replacing the air with argon or nitrogen.

All premium riflescopes, tube red dot sights, binoculars, and monoculars are fogproof. Nitrogen is used in most cases and the use of argon is quite rare. All optical products that are fogproof are also waterproof.

The only types of optics that can’t be made fogproof are extendable monoculars and spotting scopes.

Argon atoms are bigger than nitrogen molecules, so it’s harder for them to escape. If there is a normal sized leak, both gasses would escape and air would replace them. Both work the same and there isn’t a „better“ one, because they don’t affect optical properties.


Explanation of the term on our website:




Products mentioned:
Fogproof riflescopes:
Fogproof binoculars:
Fogproof spotting scopes:

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