Technically called black level, an LCD's brightness control actually adjusts how dark the black sections of the picture appear. Excessive brightness can result in a two-dimensional, washed-out look with reduced colour saturation. Images with brightness set too low tend to lose detail in shadows, and distinctions between dark areas disappear in pools of black.

Play a DVD that has letterboxing bars above and below the image and find a scene that has a roughly equal amount of light and dark material -- preferably with some details in the shadows. Turn up the brightness control all the way, then decrease it until the letterboxing bars begin to appear as close to black as possible. If you notice a loss of shadow detail -- for example, when people's eyes disappear into the depths under their brows -- then you've set the brightness too low. You may also have to adjust the backlight and contrast controls to recapture lost shadow detail.

Use the Brightness control to balance deep-black
letterboxing bars with details in shadows.

Starting at the full-contrast setting, reduce the contrast
until details are visible in light-coloured objects.

Now set the contrast. High contrast can obscure details and distort lines in the image, causing eyestrain in dim rooms. Setting contrast too low robs the image of impact. Display a still image from a DVD of a white object with some visible details, such as someone wearing a white button-up shirt. Turn the control up all the way, then reduce it until you can make out all the details in the white areas, such as the buttons and creases in the shirt.

Tip

In general, LCD sets can handle a higher contrast setting than other types of televisions. You can often set it as high as 80 percent without obscuring detail.