Simple and easy to use, this CCTV Lens Calculator calculates the lens required for a CCTV camera. Enter distance from the scene, horizontal distance of scene and height of the camera, then click 'calculate'. Results show lens required, angle of view and pixels per meter(feet). It also indicates if the object or person can be: Identified, recognised or detected only. Clicking the 'identification' button shows horizontal distance to achieve 'identification' based on resolution of camera selected. Same applies for the 'recognition' and 'detection'. The app is iPhone only compatible (5s or higher).