Understanding Your HDTV’s Menus
In our monitor and HDTV reviews, we show you every product’s OSD and how each function affects image quality. While most features are the same on a desktop screen or big-screen TV, there are some important differences you should be aware of. Let’s take a look at the terminology so you can better understand what all those controls and sliders actually do.
Backlight – You know that a computer monitor’s backlight control is labeled brightness. But on HDTVs, it’s a separate adjustment. This is super-handy because you can set the brightness and contrast for maximum detail and dynamic range, and then adjust the backlight to your preferred output level.
Brightness – So what does brightness actually control? On an HDTV, it sets the minimum black level. This is important because if you lower it too much in search of deep blacks, you will likely remove fine shadow detail, giving the picture a “black blob” look. We’ll show you the proper test pattern to use in setting your TV’s brightness on page four.
Contrast – This control sets the white level and can be used to control your display’s maximum output. Again, you want to adjust it to your preferred level without clipping detail in the image’s brightest areas. Setting it too high can also cause a color tint in bright whites that isn’t correctable with the RGB sliders. Page four will show you the proper way to adjust contrast.
Color & Tint – Here is another mislabeled option. It really should be called color saturation and color hue. Color control increases or decreases the saturation level of all six colors simultaneously. Therefore, it should be used sparingly unless all colors are under-saturated equally. Tint, or hue, rotates the secondary colors closer to one primary or another. Again, since it alters three colors at the same time, it should be used carefully.
In most cases, if you are able to dial in the color temperature correctly, color and tint can stay at or near their default settings.
Color Temperature – We also refer to this as white balance or grayscale tracking. HDTVs typically have a few presets labeled warm, normal, and cool, plus a user-adjustable mode. It’s the most important adjustment governing color because it not only sets the white point, but also affects the color gamut as well. The best way to adjust it is with an instrument. However, we’ll show you how to get close without any gear.
Other Image Enhancements
Unlike computer monitors, HDTVs include many options in the category of picture enhancements. These should be used carefully because, in most cases, they degrade picture quality and create unwanted artifacts. In fact, the movie modes on many sets disable all of them in pursuit of a more pure image, unspoiled by display-added modifications.
Sharpness – Almost every HDTV we’ve seen comes with sharpness set to a medium level. To our eyes, the resulting edge enhancement (also called ringing) is obvious and reduces the picture's clarity. All sharpness does is attempt to highlight contrasting areas of the screen by drawing a white line around dark objects or a black line around light ones. We recommend lowering this control either to zero or to a point where the ringing disappears.
Dynamic Contrast – Even though LCD is the dominant technology in today’s HDTVs, it can’t even come close to the contrast levels offered by plasma or even CRT. To compensate for this, display manufacturers introduce an algorithm that manipulates white and black levels dynamically depending on content. When used subtly, it can enhance perceived contrast. But cross that fine line and detail is lost. Most sets have three or four levels available. Start at the bottom and work your way up, watching carefully for signs of crushing. Better yet, use a test pattern.
Frame Interpolation – Most HDTVs have this feature today. Since a lot of LCDs run at 120 or even 240 Hz, the extra available frames can be used to reduce motion blur in content originating at 24, 30, or 60 frames per second. It’s accomplished through sophisticated processes that create new frames by essentially filling in the blanks. Now that it’s been available for several model generations, the tearing artifacts plaguing early models are largely gone. It works quite well at creating smooth motion and maintaining resolution. Its only drawback is known as the “soap-opera effect”. Some people, me included, are not fans of the flat and phony look that results. Since it doesn’t change other image parameters, its use is a matter of personal preference.
Now we’ll move on to a brief discussion of the SMPTE standards we employ in all our reviews and calibrations.