Camera Placement

Cameras Placement in Video Surveillance System

This article points several practical aspects of positioning cameras of video surveillance system. Camera placement is the key point of any video surveillance system. Any property has several key zones for monitoring such as entry and exit areas, doors, windows and access ways, to mention just a few of them. In the schematic Outdoor Surveillance below, you see an example of positioning two cameras for monitoring the access to the house and also the entrance to the house.

When positioning the cameras, always pay attention for obtaining a record of the most relevant information on intruder such as face, size and eventually other particular features that will further help to its finding. A good suggestion is for using colour cameras instead of black and white cameras. Skin colour, eyes colour and sometimes cloths colours might help a lot in identifying a person. There are situations such as video surveillance of babies, small children, and also in small businesses, when audio recording can be very useful, too. Some comments on main parameters of video surveillance cameras as shown in the Surveillance Camera Positioning schematic can be helpful.

The lens of most video surveillance cameras has 3.6mm focal length and 67 degrees view angle. Typical cameras can see clear images without adjusting the lens, from 2m away from the lens up to infinity. For 3.6mm lens, Camera Distance to Scene table shows horizontal dimension DH and vertical dimension DV of the scene for several values of Distance between the camera and the scene. This table is for evaluation purposes only, to estimate where you should place the cameras. The table helps you also for positioning multiple surveillance cameras. However, for final positioning of each camera, you must use the camera image displayed by the surveillance system monitor.

Sometimes you must do surveillance of a wide scene, such as shown in Multiple Cameras Layout schematic. In this case, the surveillance must cover an area much wider than a single camera can handle. Obviously, you must use multiple cameras with reasonable overlap of their viewing scenes. Avoid gaps between the viewed scenes for having the full coverage of the area under surveillance.

You must be aware to not mount the camera at more than 10m or 30ft from the scene. Most of surveillance cameras such as Foscam FI8910W Pan & Tilt IP/Network Camera have 640×480 pixels (300k pixels over entire image). This pixel count does not provide clear enough pictures for objects located at more than 10m or 30ft away from camera. For objects located up to this distance, the pictures have reasonable clarity, as you can see below in Mounting Wireless Surveillance Camera schematic.

Mount your camera as shown in the diagram above pointing to the door, but avoid targeting a bright background. If the camera targets a bright scene such as a window, as shown below in Camera and Light Sources schematic in the right hand side, is difficult to identify the intruder face. Obviously, this is not the purpose. The best position for the camera is with the window behind, such as shown in the schematic below, on the left hand side. However, the camera must avoid targeting the bright sources.

Surveillance cameras are equipped with infra red LEDs for illuminating the scene appearing in total darkness to the human eye. Video recordings made in total darkness do not not have the same clarity as the scenes recorded in visible light. However, they give a good idea about the human faces, as you see in the Surveillance in Total Darkness schematic below. Ideally, the camera must be positioned at a convenient height, for having a good record of human faces, too. Be aware that very often, the thieves wear either a hood or a baseball cap, for making their face hard to identify.

We hope that this article provided you some useful tips for installing yourself the surveillance cameras at home and also at your small business.

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