let me say something which i know......BRIGHTNESS and CONTRAST. I explain the effect that these controls have on picture reproduction, and I explain how to set them. This note applies to computer monitors, studio video monitors, and television receivers.
Unfortunately, the labels BRIGHTNESS and CONTRAST are misleading with respect to their functions: The control called BRIGHTNESS mainly affects reproduced contrast, and the control called CONTRAST ideally affects only brightness! The misleading labels have led to a great deal of confusion about how to set up a monitor for good reproduction.
the BRIGHTNESS control, more properly called BLACK LEVEL. It adds or subtracts an offset, or bias, into the red, green, and blue signals. This control should be adjusted so that black picture content displays as true black on your monitor. Misadjustment of this control is the most common problem of poor quality picture reproduction on computer monitors, video monitors, and television sets. Later in this document, I will explain how to set this control properly. The setting is somewhat dependent upon ambient light. Modern display equipment is sufficiently stable that frequent adjustment is unnecessary.
the CONTRAST control, preferably called PICTURE. It applies a scale factor (gain) to the red, green, and blue signals. It affects the luminance (proportional to intensity) that is reproduced for a full white input signal. Once BRIGHTNESS is set correctly, CONTRAST should be set for comfortable viewing brightness