Dahua SD4D425MB-HNR PTZ IP camera 4 MP, 25× zoom, IR 100 m, PoE

A 25× optical zoom really changes the focal length of the lens instead of stretching pixels the way digital zoom does. From one mounting point you can watch a wide yard and also a person or vehicle far away. The 1/2.8″ STARVIS CMOS sensor delivers a 4 MP picture at 2560 × 1440 and up to 25/30 frames per second, so movement stays smooth even when zoomed in.

Starlight technology means the camera keeps showing a colour image in very low light for longer than an ordinary camera. In total darkness two light sources take over: IR illumination gives a black and white image at up to 100 m, and the warm light gives a colour image, also at up to 100 m. Colour night footage shows the colours of clothing and cars, which is valuable when an incident is investigated later.

WizSense is Dahua's AI series, which uses a dedicated AI chip and deep learning algorithms and concentrates on people and vehicles. SMD 4.0 smart motion detection filters out much of the movement caused by leaves, shadows and rain. Perimeter protection alerts you when someone crosses a defined line or enters a zone, and face detection marks faces in the recording so the moment you need is found faster.

IP67 means a dust-tight housing that also withstands temporary immersion in water. The camera operates from –40 to 70 °C and at up to 95% relative humidity, so Estonian winters and damp autumns are no obstacle. It is designed for ceiling mounting, weighs 2.4 kg and measures 160 × 160 × 270.4 mm. There is no Wi-Fi: the connection is wired, with power over PoE or from a DC adapter.

According to the manufacturer, the camera supports cloud management, so it can be administered even when you are away from the site. That is convenient for companies with several locations or for installers who maintain a client's system. PoE power simplifies installation: one network cable carries both video and power, so there is no need to run a separate mains outlet to the camera.

Industrial and warehouse sites, car parks, fuel stations, construction sites and larger properties where one pan-tilt camera has to cover a big area and there is little light at night. It also suits a municipality or housing association that needs to watch a wide courtyard or a stretch of street. Installation and PTZ setup call for network and surveillance know-how.