4K detail looks great on a huge Ultra HD screen, even up close

Ultra HD TVs have the highest resolution of any consumer TV yet, 4K, which means that images have more detail than even 1080p high-def content. The illustration here shows you what we mean. It's blown up, but it gives you an idea of what's happening on the screen.

That doesn't mean the overall picture quality is necessarily better, because factors such as brightness, contrast, and color accuracy play a big part. Our TV Ratings illustrate that point perfectly. The best 1080p TVs have picture quality as good as—and in a few cases better than—some Ultra HD TVs.

The difference is in the detail

The more pixels in a given space, the more detailed an image looks. As a screen gets bigger, you need more pixels for sharp detail. The apples above represent a half-inch worth of pixels from a 60-inch screen. From left to right, they represent standard definition, full HD (1080p), and ultra HD. The HD image has six times as many pixels as SD, and ultra HD has four times as many as HD. The difference is obvious up close, at normal reading distance. From farther away, it’s hard to tell HD and ultra HD apart, but SD still looks coarse.

—James K. Willcox

Read "Ultra HD TVs: Best Picture Yet" for the 10 things you need to know before you spend a bundle on a UHD TV.

If you get too close to a TV, you’ll see the tiny dots making up the images rather than smooth, natural detail. With a UHD TV, you can sit much closer than to an HDTV without seeing the pixels. That means you can get a larger set without having to move your sofa farther from it. So at a normal distance of 8 feet or so, you can trade up from a 55-inch 1080p set to an 85-inch UHD TV—assuming you can afford it. With the larger screen filling your field of vision, you may find that it creates a more theaterlike experience. That's especially true with a super-large screen like Samsung's new 105-inch UHD set (shown).

But before you spend a bundle on any UHD set (even one that costs less than $120,000), check out our expert's take on the value of 4K resolution. Prices have already dropped considerably since that was written, so we may be getting closer to the point that UHD will make sense for more consumers. We just finished testing several of the newest Ultra HD sets and will be adding them to our TV Ratings next week, so come back to see how well they did.

—J.K.W.

This article also appeared in the September 2014 issue of Consumer Reports magazine.