How to Calibrate a Video Display

Take your display as far as it can go toward full performance potential by performing TPV’s basic “front-panel” calibration

Guidelines for where CONTRAST is set properly on your display will vary, but the above procedure is your best guide. Trust your eyes. As a point of reference, after adjustment it’s relatively rare in my experience with typical consumer displays for CONTRAST to be set above the 50% point in the possible range of contrast settings, so don’t be nervous if the “correct” setting is quite low.

Back in Black

From the CONTRAST pattern chapter, skip forward and you’ll come to the BRIGHTNESS/SET-UP pattern page. BRIGHTNESS is not the most logical name for the adjustment on your display that affects black level; nonetheless, that’s what it’s called. The purpose of this pattern, and others like it, is to present areas of an image that are just above, or just below, the threshold of absolute black in the signal itself. How you use this pattern depends on whether your DVD player can display signals below black. Whether it can or not, the idea is that you should be able to distinguish between the charcoal-colored areas of the pattern near absolute black and absolute black itself. If you can see the difference between absolute black and 2% above black, you’re going to see all of the shadowy details that you’re supposed to see in the dark scenes of movies—and just as importantly you won’t see the parts of the image the film-makers intend to be shrouded in darkness. In other words, black level should be low enough so that black is black, but not so low that details near black are “crushed” or obscured.

When you play this test, the center of the pattern is a charcoal-gray THX logo. Turn the BRIGHTNESS adjustment on your display up high enough so that the “drop shadow” behind the letters is revealed. If you can’t see the drop shadow, check your DVD player settings to make sure that the player is adjusted to display below-black information. Unfortunately, manufacturers use different words to describe this adjustment, and those words seldom are: “Pass Information Below Black.” Some players will offer a choice between a 7.5 IRE and a 0 IRE black cutoff; some offer a “lighter” or “darker” setting. Choose the setting that makes the blacks blackest. If your player doesn’t show the drop shadow no matter what you do, don’t panic. The THX pattern allows you to set black level correctly whether or not your player displays “blacker-than-black” information.

In cases where you can see the THX drop shadow, lower the BRIGHTNESS control until the drop shadow just blends into the black background of the pattern, disappearing entirely— and you’re done. If you can’t see the drop shadow, look at the rows of black boxes at the top and bottom of the screen. There are seven of them. Lower the BRIGHTNESS control until you can just barely make out the seventh box. (This box is just slightly above black.) When you can just make it out, you can be confident that you’re seeing the distinction between barely-above black and your DVD player’s absolute black, which is now represented by the black background of the pattern. You’ll also be seeing as much shadow detail as your DVD player and display can extract from the signal they’re being fed. As a guideline, most displays will be properly adjusted for black level at BRIGHTNESS control settings well below 50% of the range. Some displays will be adjusted much lower. Again, let the pattern and your eyes be your guides, not an arbitrary presupposition about which number setting you think should be right.

Black and white levels are interactive. After you’ve set the black level, chapter-skip backward and re-check the white-level adjustments you made, and if you touch that up, also touch black level up again before moving on.

In Living Color The next item in the THX Optimizer set of video test patterns is the COLOR AND TINT SET-UP. Your set’s COLOR control adjusts the intensity (amplitude) levels of the primary colors of red, green, and blue, while TINT/HUE adjusts the intensity of the complementary colors (yellow, cyan, magenta). These two adjustments are likely to be named correctly in your display’s menus. To set these adjustments properly with this pattern, you need a blue filter, which you can purchase from a photography store, or a pair of blue goggles, which you can buy from THX.com. An easier way—and a way you may inclined to follow if you’re particular enough about picture quality— is to buy a copy of one of the dedicated test-pattern discs now available, such as Joe Kane’s Digital Video Essentials (my choice). This disc comes with a set of red, green, and blue filters.

If you’re willing to buy the blue filter, the instructions are simple. Looking through the filter run the COLOR control on your display up and down until the “color” words in the pattern are a uniform blue (see illustration). Do the same with TINT. Done deal.