An adjustable electronic shutter controls the light striking the CCD image sensor.
A closed-circuit television camera with an adjustable electronic shutter operation is referred to as a Sens-up, Sense Up or DSS-camera. This technology enables a CCD image sensor to receive enough light even in dark conditions. For surveillance, for example, an optimum image should display clarity and color with little blur or distortion.
CCD Image Sensor
In digital color cameras, the charge-coupled device image sensor is a layered semiconductor material that allows light detection. Adjusting a slow shutter speed adjusts the amount of light striking the sensor. The DSS communicates with the video sensor to control the right amount of light prior to transmitting the data for processing.
On-Screen Display
The on-screen display allows the user to adjust settings, such as the DSS parameter. Entering the programming menus controls the amount of light that strikes the sensor. Fox example, 2X refers to two times the normal light. This parameter is different from the shutter speed on still digital cameras.
Advantages
A CCTV camera with Sens-up does not require artificial light to transmit in low lighting conditions. Ambient light plus a low sense-up limit with a high resolution camera can produce better image quality than a high sense-up limit on a low resolution camera. During regular lighting conditions, the camera returns to normal settings. This camera type works best with still objects. For example, a person stopped at a barrier may be still enough while the video sensor accumulates light.
Disadvantages
If the subject moves before the CCD sensor accumulates enough light, the result may be a blurry image. For example, a vehicle passing through an intersection displays a blurry or streaking license plate. If the on-screen settings for sens-up are adjusted at a higher limit to allow more light, such as more than 8X amplification gain, the image quality suffers. An alternative technology is an infrared camera with a sens-up and low-light enhancement better suited for an environment with total darkness.
Examples of DSS-Cameras
The LG L5213-BN is an analog camera with a horizontal resolution of 620 TV lines and a digital zoom of 8X. This dome camera has a minimum illumination of 0.06 Lux with the Sens-up in off mode and 0.000001 Lux in black and white mode, with Sens-up in Auto 128X. The Monalisa VCM-24VFH features an ultra-high resolution of 600 TV lines. Minimum illumination is 0.005 Lux for black and white and 0.05 Lux for color. The OSD includes auto white balance. This camera works with a DC Iris Vari-focal lens. The AP-HD6 box camera features a Sony Super HAD CCD II sensor with on/off motion detection. Digital zoom ranges from 1X to 10X. The electronic shutter speed ranges from 1/60 second to 1/100,000 second. The minimum illumination is 0.1 Lux at f1.2 for color and 0.0001 Lux at Sense-up mode 256X.
Tags: amount light, camera with, electronic shutter, shutter speed, with Sens-up, adjustable electronic, adjustable electronic shutter
