Start With the Objective
Good CCTV design is not about counting cameras. It starts with what each camera must accomplish. Before you place a single device, write down the goal for that view. The common framework sorts goals into three levels:
- Detect: confirm that activity is present.
- Recognize: tell a known person or vehicle from an unknown one.
- Identify: name an unknown person from the footage alone.
Each level demands more pixels on target. Identify at a doorway needs a tight view. Detect across a yard can run wide. Mixing the two on one camera usually fails both.
Translate the Objective Into PPF
Once the goal is set, convert it to a pixel density target on the subject. Detect lands near 25 pixels per foot, recognize near 50, and identify near 80 to 100. Calculate PPF at the farthest point the subject can be in that camera’s view, not at the centre. This single discipline prevents most disappointing installs.
Survey the Site
A design done from a floor plan alone will miss things. Walk the site. Note these items:
- Mounting heights, surfaces, and sightlines.
- Glare sources, windows, and backlighting through the day.
- Lighting at night, including dead zones.
- Cable paths, conduit, and power locations.
- Obstructions like signage, columns, and seasonal foliage.
Photograph each proposed location. In Canada, account for the season. A clear summer sightline can be blocked by snow load or bare-versus-leafed trees, and a camera on a cold exterior wall needs an enclosure rated for the local low.
Placement and Field of View
Set each camera to meet its PPF target across the required field of view. Mount low enough to capture faces, since a high ceiling camera often gives you only the tops of heads. Watch the angle. A camera aimed too steeply at an entrance reads foreheads, not faces. Cover the approach, the choke point, and the exit as the situation calls for.
Lighting and WDR
Cameras need usable light. Where scenes mix bright and dark, such as a glass entrance with daylight behind people, use cameras with wide dynamic range (WDR) so faces are not lost to silhouette. Plan supplemental illumination, infrared or white light, for dark areas. Confirm infrared reach against the actual distance to target, since rated range often assumes ideal conditions.
Network and Storage Sizing
Sum the camera bitrates and confirm the switches, uplinks, and PoE budget can carry them. Size recording storage from bitrate, camera count, retention, and RAID overhead. Build in headroom for added cameras and longer retention. Keep recorders on a network segment that isolates them from general traffic and applies current cybersecurity guidance.
Commissioning and Acceptance
A design is not finished until it is verified.
| Check | What to Confirm |
|---|---|
| PPF | Measured density meets the stated goal at the far point |
| Focus and exposure | Sharp across the scene, day and night |
| Field of view | Matches the design intent, no gaps |
| Recording | Frame rate, retention, and motion settings correct |
| Time sync | All cameras share an accurate clock |
Test against the written objectives, document results, and walk the client through the live and recorded views. Confirm ONVIF interoperability with the recorder, and keep signage and privacy practices in line with applicable Canadian rules.
References
Last updated 2026-06-14.