Using advanced computer design, combinations of low dispersion and high refractive index optical glasses and durable multilayer deposition coatings, Explore Scientific 100deg. 20mm Nitrogen-Purged Waterproof Eyepiece is optimized to produce high contrast, high resolution and superior flat field characteristics. And yes, this eyepiece is indeed ruggedized and waterproof to withstand the outdoor environment.
The visual effect of this eyepiece with its long eye-relief and 100deg. apparent field is an extreme full-immersion experience. You have to try it understand the visual impact that this eyepiece can produce.
The lens elements of this eyepiece are meticulously cleaned and aligned before being installed in its precision machined lens barrels. Each lens and lens grouping have EMD (Enhanced Multilayer Deposition) Coatings and are edge-blackened to eliminate light scatter and maintain image contrast. Contrast is further enhanced with baffles that mask and deflect unwanted stray light.
This Nitrogen-Purged Waterproof eyepiece is internally sealed and purged with inert, dry nitrogen gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus and to maximize the life of the internal coatings. To make sure, this eyepiece is tested by submerging it down to 1 meter of water for 30 minutes.