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HD TV 101 — A Quick Glossary

April 10, 2017 | Comments

Odds are pretty good you’ve seen the alphabet soup describing modern flat-panel televisions — especially now that plasma sets have gone out of production. But what do all those numbers and letters mean?

We’ve taken a few entries from our larger guide, Translating Tech-Speak into English, to help you navigate the jargon that goes with the sets you can purchase right now. (Note that all of these terms primarily apply to the images these sets deliver, not the audio. We’ll cover that in a separate entry.)

Something to note if you’re in the market for a new television: Does the person who’ll be installing your set know how to calibrate it? Even the most expensive TVs are set at the factory to make the picture look good in a big-box store under screamin’ fluorescent lights. Having a pro calibrate the set can reduce energy consumption and extend the life of your TV considerably — not to mention making your favorite movies and shows look much, much better. (Find a CEDIA pro near you here.)

1080p: That’s a common resolution currently available for high-definition televisions. It’s one aspect of the amount of pixels that give a hi-def image: 1,920 wide by 1,080 high. CEDIA’s Director of Technical Curriculum David Meyer adds: “The ‘p’ is for progressive scan, where a whole frame is presented in a single pass, as opposed to interlaced where only every second line is presented per pass.”

4K Ultra HD: The next step up from 1080p, it’s four times the number of pixels you’d get on a 1080 display. The terms “4K” and “Ultra HD,” when used together, are a little redundant: they’re essentially interchangeable. Even though there’s not much content out there in 4K yet, the library’s growing fast. Also, 4K TVs can “upconvert” a 1080 signal to make the picture a bit sharper (when the converter’s working properly).

Aspect Ratio: The ratio of the width to the height of an image. Analog and standard-definition digital television uses a 4:3 (1.33:1) ratio (slightly wider than it is tall), while high-definition television uses 16:9 or 1.78:1 (almost twice as wide as it is tall). Even wider aspect ratios are available in projection systems, such as 2.35:1 — similar to most widescreen motion pictures, like those shot in the format called “Cinemascope.”

There are new versions of LED becoming available, OLED and QLED.

Color Gamut: The range of color a screen or display presents to your eyeballs.

Color Saturation: A term to describe how vivid and intense colors in the display appear, independent of brightness. If the color saturation is too low, colors appear washed out, but if the color saturation is too high, colors may appear too vivid.

Contrast: The relationship between the lightest and the darkest areas on a display device or picture. A small difference means low contrast and a large difference means high contrast.

LCD television:  A video display technology that uses a liquid crystal display — generally, when you see a TV that’s denoted “LCD,” the crystals are being lit with fluorescent lighting.

LED television: For these TVs, light-emitting diodes are providing the illumination of the liquid crystals, usually from behind. They’re clearer and thinner than LCD TVs, and as a result, are now pretty much the dominant format when it comes to flat-panel televisions. (There are new versions of LED becoming available, OLED and QLED. See below.)

OLED TV: Organic light-emitting diode TV. This version of the LED technology allows displays to become super-thin and, at times, flexible. CEDIA’s David Meyer goes deeper: “OLEDs are the only type of TV currently available that actually uses the LEDs to produce the image. Every individual pixel is a separate LED cluster, and each can be turned off to achieve true black. That’s why OLED blacks are so much better than edge-lit or even 'local dimming' LED backlit LCD TVs.” The downside? They’re pricey, and there are still concerns about these sets’ longevity.

QLED TV: Quantum-dot light-emitting diode TV. A quantum dot is a kind of “nanocrystal” (which means it’s really, REALLY small), and some manufacturers are touting QLEDs as superior to OLEDs. Meyer adds: “The quantum dots augment the LED backlighting to give more brightness but also much better colors, as the nanocrystals literally light up in different colors. Still uses LCD as the imager.”