I recently finished a side-by-side comparison of two new, 240Hz 1080p LCD TVs for a major TV brand. Both TVs employ LED-backlighting technology, and both should be quite popular during the upcoming holiday buying frenzies at big box stores.

The larger (55") set uses clusters of white LEDs mounted directly behind the screen. It’s not as thin as the smaller (46") set, which employs edge illumination and is so skinny it could disappear behind the couch cushions.

Both sets can produce dazzlingly bright images. Some of the factory brightness settings exceeded 400 nits, which is over 115 foot-Lamberts! Try watching that in a darkened room at night and see how long it takes before you reach for a pair of sunglasses, a bottle of Excedrin, or a tube of sunscreen.

Both models also employ active (dynamic) LED dimming, tied to the average brightness level of the video content. This process results in huge swings in brightness readings, not to mention black levels. Unfortunately, it also results in dim white titles on a black background, or washed-out blacks in scenes with strong highlights.

And that 240 Hz processing sure cleans up motion judder and blurring from filmed and live HD content! In fact, it works so well on both sets that movies take on the appearance of live TV. I’m still undecided as to whether this is a good thing, or a bad thing.

As I wrapped up my tests and began documenting the results, it occurred to me that there are plenty of band-aids and patches being applied to LCD TVs these days to "fix" a host of image quality issues. Black levels are one of them to be sure, and it certainly can’t hurt TV sales to push contrast levels higher and higher. And LEDs can display larger color gamuts then ever before, provided that someone actually authors video content to support those wider gamuts.

Yet, even with these new levels of brightness, color saturation, and contrast, there are still major problems with LCD TV off-axis viewing and the corresponding shifts in black levels, contrast, and brightness that result. And neither of these cutting-edge models addresses any of these problems adequately.

The 46" LCD set had a noticeable color shift towards magenta when the horizontal viewing angle was shifted by just 30 degrees. Not only that, black levels around the edge of the TV had a blotchy, uneven appearance. The 55" model also exhibited washed-out blacks at the same horizontal viewing angle, and a color shift towards cyan was seen in dark grays as that angle increased.

The effect was most pronounced when viewing an 11-step grayscale ramp. Viewed head-on, each level of gray had the same color tint: None. But as soon as I started moving left or right, the middle gray bars took on a magenta color cast, while low grays moved towards cyan. Watching TV shouldn’t be this tricky.

Will these problems make a difference to the average buyer stalking the aisles at Best Buy or Wal-Mart? Probably not, as they’ll be focusing on other stuff like screen sizes and discounts. And that’s too bad, because image quality really should be #1 on anyone’s list when considering the purchase of a new TV, particularly one that costs a couple thousand bucks.

After finishing and filing my report, I walked downstairs to my family room and turned on a football game on my year-old, 42-inch 1080p plasma TV, a product that may soon make the endangered species list in California.

Imagine that - no color shifts, no brightness uniformity issues, no motion blur, nice deep blacks, saturated colors, and excellent contrast…no matter where you sit in the room.

Sigh…