March 09, 2017 | Miles Durie

The 411 on 4K

Advancements in screen resolution come at a cost. Is it worth it?

When it comes to television, more pixels are always better, right? Higher resolution, higher definition, bigger numbers are good. It seems so obvious.

Yet, as is often the case when talking about technology, it's not quite that simple.

The newest advancement in TV video resolution is 4K, also known as Ultra High Definition (UHD). It's been on the consumer market for about four years. But what does it mean?

To understand 4K, you've got to take a trip back in time. As recently as 10 to 15 years ago, the standard home theatre setup included a comparatively massive TV that displayed its analog picture on a Cathode Ray Tube (CRT) screen, usually with an effective resolution of 640x480 pixels. That was the standard for more than
50 years.

By the mid-2000s, widescreen digital TVs were slowly taking over, obsolescing CRT's horizontal scan lines and offering increased resolution of 1280x720 (720p) or 1920x1080 pixels (1080p).

Fast-forward to today. 4K TVs now double older HDTV resolution by displaying 3840x2160 pixels.

The first public HDTV broadcasts in North America took place in 1996, and within a few years, cable and satellite providers were offering HD channels.

DVDs looked pretty good on an HDTV, but the launch of high-capacity Blu-ray format in 2006 really enabled high-definition screens to reach their full potential.

The difference between HDTVs and the CRT televisions they replaced were obvious. At normal viewing distance, the image is as clear and crisp as a photograph, sharper than most cinema screens.

Viewing distance is where it gets interesting. Because of the way human vision works, higher picture resolution is more apparent closer to the screen, explains audio-visual technology writer Carlton Bale (carltonbale.com).

People generally view screens from approximately eight feet away. At this range, for someone with average vision, the benefits of high definition over standard definition are noticeable, assuming the screen size is about 42 to 50 inches. Smaller screens show less of a difference, and of course the old, sad CRT isn't even in the contest.

Now consider 4K TV. With a 50-inch screen, you'll have to sit less than four feet away to truly appreciate the higher pixel density, according to Bale's calculations. Sony recommends an optimal viewing distance of five to six feet for its 55- and 65-inch 4K TVs.

From the typical eight-foot-plus viewing distance, you'd need to invest in a screen of around 130 inches to see all the available detail, Bale says.

But there's more to it than just counting pixels, explains Murray File, audio-video manager at London Drugs' 130th Avenue S.E. store.

"It's true that to notice the difference in pixels you have to sit closer, but there are some other advantages to 4K TVs," File said. "Your colours and brightness are more accurate, your black levels are stronger, and those kinds of factors really improve the viewing experience at any distance."

The average screen size sold in the last year was 55 inches, File says, and at that size "you won't even find a 1080p television anymore."

On the other hand, for 32-inch and smaller screens, the effective pixel density at 1080p, or even 720p, is enough to make 4K seem like overkill.

With 4K source material becoming more available – on Blu-ray, from Netflix and YouTube, and from conventional TV providers – it's inevitable most people's next TV will support the format.

Should you rush out and buy one? Sure, if you're in the market for a new TV anyway, it's smart to get the best one you can afford.

"It's total future-proofing," File says. "Flat screen or curved, 3D or not, if you get a great TV, it's going to last you the longest."

Be aware that 4K video also packs a lot of data. A two-hour movie will total around 20 gigabytes, so if you're streaming, know your Internet provider's bandwidth policy. You'll also need a reliable download speed of 15 megabits per second at minimum.

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