Published: Aug 19, 2014 5:48 PM EDT
Updated: Aug 19, 2014 6:21 PM EDT

(Consumer Reports) Just when you thought you had the sharpest picture possible on your high-definition television, manufacturers are promoting ultra high-definition, also called ultra HD, UHD or 4K. It takes picture detail to the next level.

Should you buy an ultra high-def TV? Consumer Reports just tested some of the latest sets.

You can't miss the ultra high-definition televisions on display at this store. But you might wonder what sets them apart from other high-definition TVs.

Consumer Reports has tested several 50 to 60-inch UHD sets from big names like Samsung, Sony and Panasonic. Television expert Jim Willcox says ultra high-definition TV has a lot to offer.

"Ultra HD TVs have four times the number of pixels as regular high-definition sets, so they're capable of razor sharp detail, especially if you stand up close," said Jim Willcox of Consumer Reports.

But here's the rub: from farther away, say, the distance you might be sitting in your living room, the difference between ultra high-def and high-def can be difficult to detect.

Another issue is what to watch.

"Right now there's not a lot of 4K content to watch, so that means you'll be watching a lot of regular HD content on your ultra HD TV," said Willcox.

How does that look? Actually, quite good testers say, because the ultra high-def sets can "upconvert" regular HD programs to the higher resolution, making details look smoother.

"How well a TV performs this upconversion process is one of the things that differentiates sets," said Wilcox.

So, should you buy an ultra high-definition TV?

"If your TV breaks, you might want to consider an ultra HD TV. But for most people, a regular high performing, 1080p high-definition TV is still a great option," said Wilcox.

Those ultra high-definition sets Consumer Reports tested cost between $2,000 and $8,000.

A great 60-inch 1080p high-definition TV costs far less. Three to look for are the Sharp Aquos LC-60EQ10U for $1,300, the Samsung UN60H6350 for $1,400 and the LG 60PB6600, a plasma TV, for $850. All three are Consumer Reports Best Buys.