A BREAKTHROUGH in technology now allows cameras to produce excellent picture quality under all conditions.
A constant challenge facing CCTV manufacturers is to develop a camera, which produces clear, well-defined images under all conditions, yet which can be sold at a price level, which allowed mass-market accessibility.
Modern cameras such as the new Philips Dinion range, available from Bosch Security Systems , incorporate special video processing devices that offer advanced picture enhancement techniques at a more affordable price.
These modern devices are much more than just general video digital signal processors. Combining Philips' expertise in Lens Wizard guarantees proper focusing.
An example of these modern techniques incorporated in Dinion is NightSense. As the name suggests, it detects when light levels are becoming too low to permit proper colour image reproduction, combining the signal from two pixels normally used to produce a colour image in monochrome to increase the signal and the signal to noise ratio.
The camera automatically switches to monochrome and the sensitivity of the Dinion is increased threefold, which corresponds to a 9dB improvement. The resultant picture shows clear detail and high contrast even when there is very little illumination present (e.g. at dusk or with street lighting).
Autoblack is a technique that has been used extensively in high-end monochrome cameras but needs extensive video processing to operate in colour.
Autoblack basically analyses all the grey levels in the image then 'stretches' them so the darkest one becomes black and the lightest one turns white.
This gives an extremely natural looking image with far more contrast. It is ideal under foggy conditions, when the camera housing window is dirty, if the scene is 'washed out' due to a heat haze - or any situation where contrast range is reduced.
Conventionally applied in outdoor situations it is also invaluable for indoor applications. Pubs, discos, clubs and other entertainment centres are notoriously demanding applications for CCTV cameras because of the dim lighting and the amount of smoke present.
Again this technique which improves the picture quality in virtually every situation is available in both monochrome and colour Dinion cameras.
Focusing the lens of the camera is one of the main obstacles to optimal image reproduction. Most cameras are set up during the day, when high ambient light levels cause the iris to close down, resulting in an increased depth of field.
But when it gets dark, the lens opens up and the depth of field reduces, often considerably, which can lead to crucial areas - such as the entrance to a building - being out of focus.
The Dinion gets round this by means of its Lens Wizard. During installation, the Lens Wizard allows the camera to simulate low lighting conditions by forcing the iris open, so the depth of field is at a minimum and the optimum focus can be set.
The camera's in-built intelligence means it is ready to operate with optimised 'out of the box' picture quality.