In brief: a camera meant to deter is specified differently from one meant to identify someone. Decide what each camera is for before you buy it. That one decision prevents most CCTV disappointments.
Start with the purpose
Most CCTV conversations start with cameras and end with a price. The systems that work start with a different question: what is this camera for? Deterring, detecting and identifying need different lenses, positions and distances. When they’re mixed up, the footage lets you down at the moment you need it.
Deter
Visible cameras change behaviour before anything happens. For deterrence, presence matters more than image detail. Active deterrents go further: a light, a warning tone or a spoken message can intervene as something happens.
Detect and identify
The industry measures detail with a scale called DORI: Detect, Observe, Recognise, Identify. Each level needs a certain number of pixels on the target. A camera that can detect someone crossing a car park may be nowhere near sharp enough to identify their face or read a number plate. Topic 9 explains the levels.
Alerts and remote viewing
Modern systems can tell a person or vehicle apart from a passing cat. They can alert you as something happens and let you check the site from your phone. None of this replaces good camera positions. It makes good positions more useful.
The question worth asking first
A system specified around a clear purpose outperforms one specified around a budget alone. Agreeing each camera’s purpose takes one short conversation, and it prevents an expensive rework.
Electronic security for over a decade, after an early career in IT networks.