| For internal or external use |
| Cameras may be housed in purpose designed housings which are built to an IP rating, typically IP 65. For external use they include a demister for minimizing the window of the housing from misting with changing environmental conditions. |
| For specific lighting levels |
| Different cameras are designed to operate at different levels of lighting. Because colour production is less capable of operating at lower levels of lighting, many cameras incorporate a facility such that when the lighting level falls below a certain lighting level, the camera switches from colour capture to black and white, known a monochrome. When the lighting level increases the capture reverts to colour. |
| Lighting can be assisted by using additional lighting, white light is required or infr-red from purpose designed lighting. |
| Infra-red Lighting |
| A purpose designed source of lighting which is often recognized as a red glow. The red glow may not be acceptable, say in domestic areas, in which case different frequencies of light source can be chosen so that the red glow is invisible. |
| Physical size |
| The size will be influenced by consideration of the aesthetics, whether the camera is to be used as a deterrent and therefore needs to be obvious or whether it is to be inconspicuous. |
| Cameras may be mounted in the shape of a dome whereby it is difficult for someone to see the area the camera is viewing. Alternatively the camera can be traditional in shape without a housing if it is internal or mounted in a box shape housing for external use. |
| Covert use |
| There are occasions when a crime is suspected and evidence is to be gathered for a persons or persons to be charged. |
| For detail to be collected by the camera |
| The detail is referred to as the resolution of the camera and more recent cameras with high resolution are known as mega-pixel cameras. |
| Whether the camera view is to be changed remotely |
| Cameras may be moved to view differing views and the control can either be by an operator using a CCTV keyboard or the system programmed to move and automatically view a number of specific scenes which is known as tours. |
| Vandal Proof or Vandal Resistant |
| Dependent on the environment the housing of cameras are designed to resist different levels of attack. |
| Camera Lens |
| The first need is to decide on the requirements of the particular camera to which the lens is to be fitted. |
| View - lens can be chosen for wide views or zoom views for close up views of objects some distance from the camera. |
| Motorised Lenses - these can be zoomed in or out and then refocused remotely. These are used where the camera direction can be changed. |
| Auto-iris - The iris like the human eye determines the amount of light entering the camera. The function is an automatic adjustment within the lens controlled by the camera. |
