8x
The wide angle provided by the Vortex Viper HD 8×42 allows you to spy a hummingbird in your backyard, but will make the blur of its wings appear eight times closer. To prevent fogging, engineers filled the two optical barrels with argon gas, then sealed them with rubber gaskets.
10x
You’ll want a bit more power when checking out soaring hawks from a summit. The components on Bushnell’s 10×42 Nitro have a protective layer that improves clarity, repels fingerprints, and resists scratches. They’re waterproof too, so don’t worry about that accidental puddle dunk.
20x
Cheap lenses refract light unevenly, shrouding everything in a purple halo. Nikon’s Monarch 5 20×56 sports dense optics with a coating designed to correct color, so striped zebras won’t look washed out. Adjustable eye cups let you catch the sights without removing your glasses. This story originally published in the Out There issue of Popular Science.
