Basic Info

Dynamic Range

In gerenal, dynamic range indicates the difference or the ratio of the smallest and largest signal that can be handle by a device. The dynamic range of the video signal is 100 - 110 percent. In contrast, video cameras with 2/3-inch CCDs, for example, can handle a wide dynamic range of approximately 600 percent. (Dynamic range decrease depending on the camera setting.)

KNEE is a function which compresses the signals in the highlight areas so they fall within the video signal's dynamic range (approximately 109 percent: white clip point). In most cases, KNEE POINT is set between 85.0 to 100.0, which is approximately the luminance level of human skin.

In Sony video cameras, increasing the KNEE SLOPE to a positive value (making the angle of the KNEE SLOPE gradually increases the compression ratio so a greater range of the camera's dynamic range is used.
However, it's important to note that the image color of such compressed highlight areas can look pale and "washed out" with a larger KNEE SLOPE value. This is because the color difference (R-Y, B-Y) signals are compressed together with the luminance signal. To avoid this, the combined use of the KNEE function and the KNEE SATURATION function is recommended.

Some Sony cameras have a DCC(Dynamic Contrast Control) function, also called Automatic Knee Control, which adjusts the knee point and knee slope automatically.