I bought a pair of the 15X50 Viper HDs. I only kept them about 3 weeks. Their main problem was the focus was very touchy and the focus wheel was gritty. It was damn hard to get a good focus at 500+ yards. This was of course from a tripod. I called Vortex and discussed it with them. They agreed that the Viper is "challenging" to focus easily at different ranges. They gave me a screaming deal to upgrade to the 15X56 Kaibab binos. The Kaibabs were much better but still were lacking in crispness and clarity. I sold them recently. I'll probably try the Meoptas next. I do not recommend the Viper HDs!
Bob
