Explaining Camera Features

Introduction

What do all those features on that camera you’re thinking of buying do? This article will explain the most common features for your benefit. The back of a Sony SSC-E453 camera featuring dip switches for control of special features.

Auto White Balance

AWB allows your camera to remove unrealistic color casts so that objects which appear white to the eye are rendered white by your camera. An incorrect white balance can cast orange, blue, or green hues onto your image.

Automatic Gain Control

AGC adjusts the video so that a more consistent level of brightness is achieved. The signal is fed back to adjust the gain to a median level for a range of input signal levels. If the brightness is weak, AGC boosts it. If the image is too bright, AGC reduces the brightness.

Back Light Compensation

BLC is useful for adjusting the brightness of an image. It is specifically video gain used to correct the exposure of people or objects in front of a bright light source which causes the subject to appear as a silhouette. The prime example of when this feature is needed is when a person is entering through a doorway and the light from behind him makes his image dark. With BLC, his image is corrected for proper illumination.

CCD imager

A charge coupled device is a specialized type of integrated circuit located behind the camera’s lens. The lens focuses a small image of the scene onto the CCD imager, which scans the image and, with the help of other electronics, converts it to a video signal for use by a DVR or Monitor.

CS Mount

CS mount is the industry standard lens mount. It differs from a C Mount in that a CS Mount has a flange focal distance (FFD) of 12.5 millimeters while a C mount has a FFD of 17.5 millimeters. An FFD is the distance from the mounting flange (where the lens comes in contact with the camera) to the focal point. A C Mount lens is compatible with a CS Mount camera with the addition of an adapter ring, called a C ring.

Infrared

IR is the spectrum of radiation just beyond red light in the visible range and below microwave radiation. Nightvision cameras come equipped with IR lights which allow the camera to “see” without any light source.

Lux

A lx is an International System of Units for illumination equal to one lumen per square meter. It is a measure of apparent intensity of light hitting a surface. A lumen is the measure of perceived power of light.

Wide Dynamic Range

WDR doubles the exposures per frame and controls the length of time that the Automatic Electronic Shutter is open. A short exposure and a long exposure image are taken by the camera. The resulting two images per frame are then combined so dark and bright areas are reproduced clearly, with detail in both bright and dark areas. In this way, the bright areas are not too washed out and the dark areas are not too black.