Basic Info

GAMMA

Gamma is a numerical value that indicates the relationship between the input and the output signals of a camera/monitor, as illustrated in the graph below. Generally, the straighter the gamma curve becomes (y=1), the more natural the image appears to the human eye. Because monitors have a gamma curve with a value of 2.2, the camera is usually set up with a reverse 0.45 gamma so the resultant curve is close to a straight line. The lower area of the curve affects dark colors while the higher area determines the colors close to white. The middle area represents colors in-between. The GAMMA function mainly corrects the color of middle areas of the curve.

Sony video cameras offer a variety of convinient gamma functions. These are STEP GAMMA (F900R / 790)or COARSE (F900/3) for defining the area of the curve that needs to be corrected, MASTER GAMMA which corrects the entire curve, and GAMMA tables (STD and FILM) which offer a set of present gamma values. For example, you can deepen colors by setting MASTER GAMMA to a + value, then correct specific colors areas using STEP GAMMA, and finally select FILM from the GAMMA tables, creating images with rich colors and unique depth. However, because colors can be over-emphasized depending on the setting, it is necessary to check the image on your video monitor as you use these functions.