Multi-Camera Security System Planning

Volume I  ·  May 2026  ·  371 words

Planning a multi-camera security system requires designing overlapping coverage zones — each entry point should be visible from at least two cameras with different angles — while ensuring the NVR has sufficient channels, processing capacity, and storage for the planned camera count. Under-specifying the NVR at the time of purchase constrains future expansion: adding a fifth camera to a 4-channel NVR requires replacing the NVR entirely.

Channel count. NVRs are sold by channel count: 4, 8, 16, or 32 channels. Each channel supports one camera. The NVR must be sized for the eventual camera count, not the initial deployment — expanding from 4 to 8 cameras requires an 8-channel NVR from the start. The Reolink 8-channel NVR and Ubiquiti UniFi NVR are representative models. The NVR's incoming bandwidth — the total bitrate it can process from all cameras simultaneously — is a separate specification from channel count. An 8-channel NVR may support 8 cameras at 2K resolution but only 4 cameras at 4K because the processing capacity is exceeded. Check the NVR's total incoming bandwidth rating (typically 80–160 Mbps for consumer NVRs) against the sum of all cameras' bitrates at the desired resolution and frame rate.

Coverage design. Each entry point (front door, back door, garage door, ground-floor windows) should be covered by at least one dedicated camera. Critical choke points — the driveway entrance, the front walkway — should be covered by two cameras with overlapping fields of view from different angles, so that a subject approaching from one direction is captured face-on by one camera and in profile by the other. Camera height significantly affects identification capability: a camera mounted at 8–10 feet looking down at a 30–45° angle captures the top of a person's head and shoulders — poor for facial identification. A camera at 6–7 feet with a shallower downward angle captures the face directly, which is the goal for entry-point cameras. The trade-off is vandalism risk: lower cameras are more accessible to tampering.