The Display Calibrator Assistant starts by helping you set the display's contrast and brightness. (This step applies to external monitors only; it does not apply to iMacs or notebooks.) You will need to access your monitor's built-in controls, which vary from manufacturer to manufacturer. There may be an onscreen display system that lets you make brightness and contrast adjustments, or there may be dedicated control surfaces on the monitor for these adjustments. Check the monitor's manual for guidance, if needed.
Display Calibrator Assistant: Display Adjustment
The Display Calibrator Assistant starts by asking you to turn your display's contrast adjustment to the highest setting. For LCD displays, this may not be a good idea, because doing so will increase the brightness of the backlight, consume more power, and age the backlight more quickly. I've found that it's not necessary to crank contrast up to achieve an accurate calibration. You may also find your LCD display has no, or very limited, contrast adjustments.
Next, the Display Calibrator will display a grey image that consists of an oval in the center of a square. Adjust the display's brightness until the oval is just barely discernable from the square.
Click 'Continue' when done.
