Peter198

Hi everyone, I'm new here. I have to build a video surveillance system for a friend's house. The house has a square plan of 11 meters x 11 meters, the cameras (8) will be mounted 4 meters high, 2 on each side, crosswise. I just have a doubt better 2.8 or 4 mm the focal length, to distinguish a face? Camera model DS-2CD2385G1-I https://www.hikvision.com/en/products/IP-Products/Network-Cameras/Pro-Series-EasyIP-/DS-2CD2385G1-I/. Thank You very Much. .