Binoculars are widely used optical instruments and they are used for a myriad of different types of viewing. From concert or theater goers to hikers and campers, from hunters to mariners – binoculars are everyone’s best friends when it comes to viewing objects at large distances. But when you are out and about, can your binoculars survive rough terrain and stormy sea weather? What if you drop your binoculars into water or have to endure a dust storm, will you binoculars come out of the adventure unscathed?

There are many outdoor accessory providers that proclaim their binoculars to be dust and water resistant. That doesn’t mean that water and dust can do absolutely no damage to your instrument, but it simply means that the water and dust will not damage the instrument up to a certain point. For example, water proofing only holds up to certain levels of water pressure. Once that limit is exceeded, the water proofing can no longer hold up and protect your instrument from water damage.

How Water & Dust Proofing is achieved

When manufacturing a pair of binoculars, water proofing is achieved by the simplest yet most ingenuous tool called the “O ring”. The O ring ensures that there is an air tight and water tight barrier between the chassis, the objective lens and other internal parts of the binoculars. This keeps the insides of the binoculars dust and water resistant within certain situational and environmental constraints. This O ring keeps the binoculars water resistant on sea level and up to certain levels of water pressure and also keeps the binoculars dust resistant in dry and dusty environments by preventing dust and tiny debris from entering the body of the binoculars.

JIS Standard for Water and Dust Resistance

The Japanese Industrial Scale is a set of standards that rates the dust or water resistance of an instrument. The following scale will allow you to determine which grade of binoculars will suit your viewing needs best.

Dust Resistance Standards

• Grade 4: Protected against solid foreign objects 1.0 mm diameter and greater.
• Grade 5: Dust protected but not fully dust resistant.
• Grade 6: Fully dust resistant.

Water Resistance Standards

• Grade 0: Non-protected
• Grade 1: Protected against vertically falling water drops.
• Grade 2: Protected against vertically falling water drops when enclosure is tilted up to 15 degrees.
• Grade 3: Protected against water sprayed at an angle up to 60 degrees on either sides.
• Grade 4: Protected against splashing water.
• Grade 5: Protected against water jets projected at the instrument from any direction.
• Grade 6: Protected against powerful water jets.
• Grade 7: Protected against the effects of temporary immersion in water.
• Grade 8: Protected against the effects of continuous immersion in water.