AF (Autofocus)  Available in cameras equipped with motorised focus, this feature provides automatic adjustment of the focus. AF operates by varying the focus to maximise the high frequency content of the central area of the picture by reference to high luminance and strong contrast elements. In some cameras, AF can be set to High or Low sensitivity modes. AF mode is not recommended for continuous 24-hour operation. See also One-push AF, Interval AF, Zoom triggered AF.

 

ATW (Auto Tracking White balance)  In ATW mode, white balance is continuously being adjusted according to the colour temperature of the scene illumination.

 

CCD Iris  Special operating mode of the electronic shutter of a CCD camera. The shutter timing is automatically adjusted to maintain the same video output level, irrespective of the scene illumination. Can only reduce the camera sensitivity. Allows the use of a fixed iris lens under variable lighting conditions. Often combined with AGC.

ExView HAD CCD Technology  CCD technology that use a specific doping to provide enhanced sensitivity compared with conventional CCD, lower smear, improved antiblooming and improved spectral response in the near infrared.

 

Horizontal Resolution   Number of equally spaced vertical black-to white or white-to-black transitions that the camera is able to reproduce, divided by the aspect ratio (usually 4/3) to make a comparison between horizontal and vertical resolution easier. Usually expressed as TV lines per picture height. Indicates the amount of horizontal details that can be perceived. Horizontal resolution is limited by the number of pixels in one line and by the type of colour filter used, if any.

 

Lux (lx)  The SI measurement of light intensity taken at the surface which the light source is illuminating. The measure of the total lumens falling upon a unit of area. 1 lumen per square metre. One Foot-candle equals 10.76 lx.

Minimum Illumination   Minimum light level needed to achieve a 50% or 100% video output level when the camera is at maximum gain and the lens iris fully open. Can be computed from the nominal sensitivity, lens characteristics and maximum gain.

One-push AF (One-push Auto Focus)  Focus hold mode, that can be automatically readjusted as required by the user (One-push AF Trigger), assuming that the required subject is within the focusing limits of the camera lens.

 

One-push WB (One-push White Balance)  Fixed white balance mode that can be automatically readjusted as required by the user (One-push WB Trigger), assuming that a white object, in suitable lighting conditions and occupying more than half of the image area, is seen by the camera.

Pixel  Picture element.

 

Privacy Zone Masking  Function superimposing masks on the video output, to mask unwanted or prohibited areas of the picture.

RGB (Red, Green, Blue)  The primary colours of light that produce a colour video image. In video, RGB refers to a system in which these three primary colours are kept isolated and delivered from the source to the display device over separate wires. This system results in high quality pictures. RGB signals are used in some broadcast video equipment and computers.

WB (White Balance)  In a colour camera, white balance is the process of adjusting the values of its colour differences signals so that a white object in a scene illuminated by a particular source of illumination is displayed as a white or grey (i.e. no chrominance). The normal colour reference illuminant has a colour temperature of 3200 K, equivalent to a halogen lamp. The human eye is a subjective device, constantly readjusting its colour balance according to the lighting context (our eye knows what must be seen as white). Unlike the human eye, a camera is an absolute measurement device, and its colour balance has to be adjusted to suit the colour temperature of the light illuminating the scene, for example sunlight is different from 3200 K. Several adjustment modes are available, fixed values (pre-adjusted), One-push, automatic tracking. See also One-push WB and ATW.