Big, clear glass does not come cheap, which is why 80mm and 85mm spotting scopes often retail for well over $2,000. But for a serious big-game hunter, birdwatcher, or long-distance precision target shooter, that big glass is necessary to resolve distant targets in low-light conditions. Vortex has brought to the market a full-size, full-featured spotter for about half the going rate, but without sacrificing optical quality or substandard controls. We compared the Viper HD against big spotters from Zeiss and Swarovski, and while those Euro brands outperformed the Asian-sourced Vortex, they didn't win by as much as you'd expect considering the thousands of dollars in price differential. The Viper has a very crisp center-ring focus and smooth power changing in the interchangeable eyepiece.