CNET Reader Doug Hagemeister asks:

Hello! I was watching a movie on Blu-ray the other day filmed in the 21:9 aspect ratio and I realized that it technically wasn’t “1080p” since about 1/4 of the screen was taken up by the horizontal black bars (called “letter boxing,” correct?). Anyway, I was just wondering how many pixels were being used on the TV. Thank you!

Ah, letterboxing, how I love you.

Curious about the difference between active 3D and passive 3D? So was I. So I wrote this.

By now you’ve probably heard about OLED, or organic light-emitting diodes. LG and Samsung both revealed potential models at this year’s CES, with the LG winning CNET’s Best of CES Award.

Make no mistake, this is the most important advancement in TV technology in more than a decade, and a vast improvement over both LCD and plasma.

Here’s why.

The latest TV technology buzzword is “4K.” This magical alphanumeric represents a quadrupling of the now-standard 1080p resolution found on Blu-ray and most HDTVs.

Have no doubt, manufacturers are going to start pushing 4K (some already are).

The thing is, though, you don’t need 4K, because in the home, 4K is stupid.

Don’t listen to the hype. Ignore the commercials. Leer skeptically at the salesman. There is no such thing as an LED TV, and “LED” doesn’t mean it’s any better than other TVs.

LED is just a type of LCD, with strengths and weaknesses that make it better in some ways, worse in others, and rarely worth its price premium over other technologies.

Based on some comments in my recent article on LCD brightness uniformity, it seems fair to do a piece on that big bugaboo of plasma HDTVs: burn-in.

So what is it? Is it something to be concerned about? Can you fix it?

Cutting through the hype and fearmongering in 3…2…1…

Nearly every LCD TV on the market has a problem: uniformity. Certain areas of the screen are going to be brighter than other areas. On dark scenes, this can be visible and sometimes distracting.

So what causes it? What can be done?

Contrast ratio is the most important aspect of a TV’s performance. More than any other single metric, a set’s contrast ratio will be the most noticeable difference between two TVs.

That is, if you could juxtapose them. Which you can’t. Or if you could compare their claimed specs. Which you can’t.

Understanding what contrast ratio is and how to judge it will help you determine the best TV for your dollar. But it’s a lot harder than it sounds.

There’s lots of money in cables. Your money.

Dozens of reputable and disreputable companies market HDMI cables, and many outright lie to consumers about the “advantages” of their product.

Worse, the profit potential of cables is so great, every retailer pushes high-end HDMI cables in the hopes of duping the buyer into spending tens, if not hundreds, of dollars more than necessary.

Here’s the deal: expensive HDMI cables offer no difference in picture quality over cheap HDMI cables. CNET has mentioned this before, but here’s the science of why.

Some interesting comments still aren’t convincing. 4K resolution in TVs is still a dumb idea. Read this blog post by Geoffrey Morrison on TV and Home Theater.