Are motorised Pan/Tilt/Zoom (PTZ) cameras best for these systems?
There is a strong bias towards favouring fixed cameras since they ‘guarantee’ viewing their detection field. However, PTZ cameras clearly can be used, though they should be regarded as multi-position fixed cameras for purpose of event viewing, each with text annunciation of detector or area of view. They are not to be seen as a camera which may be manually operated to scan & search a protected site to ‘hunt out’ intruders. Where PTZ cameras are used, it is important not to expect too much of them by having many alarm driven presets. They can, after all, only look in one direction at a time and therefore risk missing a vital situation. Is there any particular issue to consider over lighting? BS8418 states that there should be sufficient lights on site to illuminate the camera’s field of view. In instances where permanent illumination is not an option, systems can be configured to turn lights on automatically when there is an alarm or they can be relay driven such that the monitoring cen
