EDTV Plasma vs. HDTV Plasma

Updated: June 2005
Reviewer: Phil Conner

There is approximately a 20% improvement in the picture quality when HD content is displayed on high resolution (HDTV) plasma televisions when compared with lower resolution (EDTV) plasma televisions- when viewing two plasmas by the same manufacturer.

Note: This article addresses the issue of ED ("enhanced definition") and HD ("high definition") as it pertains to the native resolutions of plasma displays. Plasma TVs are unique among fixed-pixel displays (e.g., LCD and DLP) in that similar-sized plasma displays from the same manufacturer can have entirely different native resolutions. A 42-inch flat-panel plasma display, for example, comes in at least two resolution "sizes": 854 x 480 (called ED) and 1024 x 768 (called HD). Not surprisingly, the reason is cost: It simply costs more to produce higher resolution plasma display screens due to the number of pixels included in the panel.

The purpose of this article is to explain the differences between ED plasma TVs and HD plasma TVs, and to address certain misconceptions surrounding them. To that end, I make the following observation: More pixels = higher manufacturing costs = higher price tags. But does it also equal a better picture on your plasma TV?

It's amazing how two identical-looking plasma TVs can come with such different price tags. The actual price disparity between an EDTV plasma and an HDTV plasma from the same manufacturer can be upwards of $1200. Welcome to the sometimes confusing world of fixed pixel displays, where things are not always what they seem, and one letter (an "h" instead of an "e") can make all the difference, money-wise at least. You'll pay about a thousand dollars more for a plasma unit bearing the "HDTV" distinction, but is this money well spent? Here are some of the more relevant facts in the ED/HD debate: All plasma displays contain a set number of pixels (picture elements), with which they generate on-screen images. The exact number of pixels depends on the size of your TV screen as well as its native resolution. The native resolution of a given plasma TV = the total number of pixels comprising its display element. A plasma TV with a resolution of 854 x 480 has exactly 409,920 pixels.

Therefore, everything you watch on a plasma television will be converted to its native resolution (thereby forcing the video content to "fit" onto the screen itself). This process is called down-conversion or up-conversion. The video content you watch on TV, whether its regular programming, VHS, DVD, or HDTV, has its own resolution, too. If a plasma TV has a native pixel resolution of 1024X768 (XGA resolution) and you are watching a DVD in progessive scan 480p then the internal processing of the plasma is up-converting the signal to match its native pixel resolution. Almost all incoming signals to a plasma TV are either down-converted or up-converted. This naturally places a premium value on plasma displays that do the best job with conversion techniques.

If the incoming video source has a higher resolution than your display's native pixel resolution, some degree of detail and sharpness will be lost in conversion, though it is doubtful you will actually be able to "see" this decline in detail/sharpness. There is approximately a 20% improvement in the picture quality when HD content is displayed on high resolution (HDTV) plasma televisions when compared with lower resolution (EDTV) plasma televisions- when viewing two plasmas by the same manufacturer.

If, on the other hand, the incoming video source has a lower resolution than your plasma monitor's native resolution (e.g., DVDs, most broadcast TV, etc.), then the lower resolution plasma (EDTV) will actually align better with the signal and may outperform the high resolution (HDTV) by a small margin. WHAT?? You mean I pay a higher price for a plasma with higher resolution and it doesnt look as good as its less expensive counterpart? Yes, is the answer. This occurs because the higher resolution plasma must do extreme up converting of the incoming signal to match its native pixel resolution. It can certainly occur between brands. For instance a Pioneer plasma EDTV may have a better picture with the same incoming DVD or cable feed than an HDTV from Vizio. How? The video chip processing engine in the Pioneer coupled with a better picture element (i.e. glass) for streaming video can certainly create a better picture image in the lesser resolution plasma. The lesson: Be brand conscious when contemplating a plasma purchase.

It's All In the (Vertical) Resolution.

Think of resolution as picture detail. Standard-definition (SD) TV -- the sort most of us have been watching for years -- has 480 visible lines of detail, whereas HDTV has 1,080i visible lines of detail. This is the number of horizontal lines found on your TV screen. Remember, TVs are measured on the diagonal: The width of the screen changes, while its height remains more or less constant. Thus, it is the number of pixels on the vertical axis that really determines how much detail is visible.

Theoretically, higher resolution plasma TVs should always look better with an HD signal, but with video picture signals - signal processing, interpolation, conversion and contrast(i.e., how an image is displayed) has more to do with picture quality than resolution does.

Case In Point: At past Consumer Electronics Shows (2001 and 2002), manufacturers would stage "plasma shoot outs", often pitting earlier-generation HD sets against ED ones. The outcome? A Panasonic 853X480 plasma beat several other manufacturers with higher resolutions (1024X768 or 1024X1024) even with an HD signal displayed. Contrast, video processing, and conversion have much to do with plasma technology.

So, is it really worth it to shell out extra for an HDTV?

Certainly there is more and more HD content available out there - and it will only increase from this point in time. There are dedicated HD channels. There are upconverting DVD players. And As you decide whether you want (or need) an High Resolution plasma, you might want to consider the following:

(1) DVD material may look better on an a good brand of EDTV 853 X 480 than it would on a third tier brand in a 1024X768 resolution. At DVD quality resolution, the image output quality depends more upon the manufacturer than it does the resolution.

(2) 80% of the content available to viewers -- whether on TV or on DVD -- is NOT high definition. However, this story is changing.

(3) If deliberating between a 1st tier EDTV resolution plasma purchase compared with a 1st tier HDTV plasma resolution purchase, consider that you will likely get around a 20% bump in picture quality with the HD unit when watching a good incoming HD signal. An EDTV plasma can display and HD signal, but only at its native pixel resolution after down conversion.

(4) The manufacturer quality should be of more concern than the resolution of the plasma display. Purchasing a plasma from a quality manufacturer can make the biggest difference of all. I would rather have an EDTV 853X480 plasma TV from Sony, Panasonic or Pioneer than an 1024X768 HDTV plasma from lesser Taiwanese, or Korean manufacturers even for the same cost.

(5) The best case quality scenario is an HD plasma from a 1st tier manufacturer.

(6) Displaying computer images will look much better on the higher resolution display (50%) than lower res displays. This is especially the case for static images. The extra expense of the higher resolution plasma display will be well worth it for these uses.