That way, you're not bombarded by alerts, but you don't miss anything important, either. The Nest Hello $199 succeeds by continuously recording video, so you never have the frustrating experience of firing up the app just to see video of someone walking away. Facial recognition lets you know who's at the door by name, and it can also distinguish between people and cars. What's more, you can separate the field of vision into multiple zones, which helps you customize the notifications. Design and InstallationThe Nest Hello video doorbell is sleek and slim, at 4. 6 x 1.