A Guide to HDTVs
[Page 7] Viewing Angles
If you're the sole viewer of an HDTV, then for most intents and purposes the viewing angle is not a major issue, as long as you can situate yourself directly in front of the TV at the optimal position and keep yourself there at all times. If however your viewing position is such that you can't always be centered and exactly perpendicular to the screen surface, or if there are multiple people who will be viewing the TV at the same time, then viewing angle becomes a greater concern.
The comparison is relatively straightforward: plasmas allow for viewing the screen from any angle (i.e. up to 180 degrees vertical or horizontal) with virtually no deterioration in black level, brightness, color reproduction or crispness of the image. The AR filters on plasmas can result in a slight reduction in brightness at wider viewing angles, but this is usually not major.
LCD TVs - and here the use of LED backlighting makes no difference to this issue - all suffer from a noticeable degradation of the image when viewed at progressively larger angles to the side or above or below dead center. This is simulated in the images above. The viewing angle within which image quality remains optimal can be around 30 degrees from center at best. Once again, this is due to the way the technology works. On a plasma, each individual pixel directly casts its own light from the screen. On an LCD, the source of light is the backlight behind the twisted liquid crystal, so light is not emitting directly from the pixel but from slightly behind it. This results in lower brightness at an angle.
The precise way the LCD technology works, and hence the exact viewing angle capability of any particular LCD TV, depends on the panel type. The three most common panel variants are:
Variants of the IPS panel are the preferred choice for good quality LCD screens.
Regardless of which panel type is used however, LCD TVs still cannot provide anywhere near the viewing angles of a plasma. Viewing angle cannot be altered by changing any settings or by any other method, since it's a physical limitation based on the panel technology used. Be certain you check the viewing angles for any TV in a store before purchase if this is of any concern to you.