How Many CCTV Cameras Does a Business Actually Need?

The question we are asked most often is "how many cameras do I need?" It is a reasonable question, but it is not the one that produces a good system. The better question is: what do I need to be able to see, and in how much detail?

Detection, recognition, identification

There is a practical difference between seeing that someone is present, recognising someone you already know, and identifying a stranger from footage. Each demands progressively more pixels on the subject. A camera that comfortably shows a person walking across a yard may be useless for identifying who they were.

This is why one well-placed camera at a doorway is often worth three placed high on a wall for general coverage.

Start with the list, not the count

Write down the places where something you care about actually happens: every entrance and exit, the till or cash area, the stock room, the server room, loading bays, the car park, the perimeter gate. For each one, decide whether you need detection or identification.

Then check the obstacles

• Lighting — what does the area look like at 2am, not at 2pm?
• Backlight — a camera pointed at a bright doorway records silhouettes.
• Distance — coverage width and identification distance work against each other.
• Cable routes and power — the best position is only the best position if you can reach it.

What a typical answer looks like

A small shop is often well served by four to six cameras: entrance, till, stock area, and a wide view of the floor. A warehouse with a yard usually needs more, because the perimeter and loading bays each need their own treatment. An office building depends almost entirely on the number of entrances and floors.

Do not forget storage and power

Two decisions quietly determine whether the system is useful months later: how long footage is kept, and whether the system keeps recording during a power outage. Retention comes from camera count, resolution and drive capacity. Backup power is what stops the recording gap forming at exactly the wrong moment.

If you would like a camera count with reasons attached rather than a number from a price list, we are happy to carry out a site assessment.