All About Waterproof and Fogproof Binoculars

June 7, 2010 | Posted by Best Binocular Reviews

The Waterproof Fogproof Binocular

Many binoculars are either waterproof, fogproof or both where as some manufacturers call their optics weather protected or even weather proof. But what exactly does it all mean, do you really need it and just what do they do to make a pair of binoculars waterproof and fogproof?

Waterproofing

Waterproof binoculars and spotting scopes are sealed internally using O-rings to prevent moisture as well as dust and other small debris from entering the inside of the unit.

Fogproofing

Fogproofing means that the optical barrels are filled with nitrogen or argon gas to prevent internal fogging caused when subjecting the optic to temperature extremes, especially in high humidity. Fogproofing is sometimes referred to as nitrogen-purging. This term is probably more descriptive of the actual process; O2 (oxygen) is purged from the barrel(s) and replaced with an inert gas (usually nitrogen) which doesn’t condense.

A pair of binoculars or can be waterproof without being fogproof. This merely means that the instrument is sealed, but the oxygen inside the barrels haven’t been purged and replaced with an inert gas. But if an optical instrument is fogproof, it has to be waterproof (sealed) as well.

Today even fairly inexpensive binoculars and scopes are both waterproof and fogproof. Just look out for manufacturers that claim that their optics are “weather protected” or “water protected” this usually means that they are not 100% water or fog proof, but they should survive a little moisture. If you think that you will need to use your binoculars in a wet environment, make sure that they are 100% waterproof.

Applications

Whilst it is never a bad thing, but if you are choosing between two binoculars and the one that is more expensive is water and fogproof you need to decide if you really need it. Having used fogged up binoculars I can tell you from experience that it becomes very annoying and any optical device that becomes compromised by moisture will obstruct your view and may ultimately become damaged from mold growing on the inside the barrels.

Marine Binoculars: If you plan on using your optics in any marine or water environment, I would highly recommend getting water proof binoculars as no matter how careful you are, mistakes will happen! If you are using your binoculars on a boat take a look at my article on choosing marine binoculars that are purposely designed for life on the water, that will not only handle the weather, but some will even float, have built in compasses and rangefinders and are optimized for stability.

Waterproof and fogproof binoculars are also highly recommended if you plan on using them anywhere where the humidity is high in like, rainforests, or if you’re around water like a wetland. Some of the best birdwatching can be experienced during inclement weather and one of the main reasons birdwatchers go with binoculars that have both of these features. Whilst not essential, waterproofing is also a good idea if you are taking your binoculars on safari, hunting or most other wildlife viewing as I have often taken guests out in the bush whilst it is raining with some of my bet experiences occurring during wet weather.

Dry and Sandy Environments

It is not only watery and humid conditions where water and fog-proofing can help: in an extremely dry and dusty climate, the O-ring seal will prevent dust and tiny debris from entering the unit.

Water Repellent Lens Coatings

Another feature to look out for and one that is often found on high end optics are special lens coatings that are actually water repellent or sometimes known as “hydrophobic coatings”. These water and dirt repelling properties, not only repel water, but they are have more resistance to abrasions and make it much easier to remove your fingerprints and dirt particles from the lenses. Lenses treated with the hydrophobic coating allow water to just roll off them. Take a look at the LotuTech® coating on Carl Zeiss Binoculars or the AquaDuraTM-Coating on Leica Binoculars.

Categories: Buyers Guides, Marine Binoculars | Tags: Buyers Guide, Fogproof, Waterproof Binoculars | No Comments »