Do you need a 4K TV for HDR?

HDR, or High Dynamic Range, is one of the latest TV technologies, even newer than 4K resolution. HDR can, on the right TV and with the right content, look pretty impressive. Most of the time it comes with Wide Color Gamut, or WCG, which adds more realistic colors to the mix. These help the TV create an image that's got more punch and vibrancy than non-HDR/WCG TVs .

So far these two technologies have only been available in mid- and high-end Ultra HD "4K" TVs. But is 4K required for HDR?

The answer is a rather strange "yes, but not technically."

High Dynamic Range

Just so we're all on the same page, HDR is a TV technology that lets directors and filmmakers show brighter details and (when used with Wide Color Gamut) a broader range of colors. Because this is embedded in the content itself, it's not an artificial enhancement, but rather more of what the creators intended.

Though it shares its name with the HDR photo mode on your phone or camera, TV HDR is completely different. Photo HDR is an attempt to "fake" a wider dynamic range. TV HDR actually is a wider dynamic range. For more info, check out What is HDR for TVs, and why should you care?.

The short version is, done right, HDR content on an HDR TV will make your favorite programs look even better.

HDR and Ultra HD '4K' TVs

Right now the only TVs with HDR capabilities are Ultra HD "4K" TVs. So the narrowest of answers to the question posed by the article is yes, you need 4K TV to get HDR.

However, technically you don't. I mean, you do, but, OK, it's sort of complicated.

HDR has nothing to do with resolution. 4K resolution refers (rather inaccurately) to the number of pixels on your TV -- the number of the individual dots that make up the image. HDR and wide color affect the range of brightness and colors those dots produce; the "quality" of the pixels, if you will, not the number. That's why some people refer to HDR as "not more pixels, but better pixels."

Right now all TVs with HDR and wide color are Ultra HD TVs. But because the technologies themselves are separate, a non-4K HDR isn't impossible.

This separation of resolution and HDR/WCG isn't just theory. Netflix and other services will stream non-4K HDR under certain circumstances. When you first start streaming an HDR show, often the video quality will start out lower and ramp up to 4K resolution -- but it's HDR the whole time. If your Internet bandwidth can't sustain 4K video, they'll send a lower resolution like 1080p or 720p -- but it stays in HDR. If your Internet is really bad, you might even get standard-definition HDR(!).

It's super soft and doesn't look that great, but the idea amuses me that somewhere, at some point, someone could be watching 480p HDR. The HDR data only requires slightly more bandwidth than the non-HDR or "SDR" feed.

So if a manufacturer wanted to make a 1080p TV with HDR, sure, it's possible.

Don't hold your breath

It's highly unlikely this will ever happen. The TV industry is already well on its way to making Ultra HD "4K" the standard, not the exception. There's more and more 4K content, and the price of Ultra HD TVs continues to drop. So there isn't much room at the budget end of the market to squeeze in a non-Ultra HD HDR TV.

The only niche where a TV like this might fit would be a high-end small TV (32 inches or smaller). But in the US, this market doesn't really exist. In other countries this good-but-small category is quite popular, but even so, it's doubtful TV manufacturers will dump money into making a TV that small with HDR or WCG. That's actually too bad, since HDR and WCG would be far more noticeable than increasing the resolution in those screen sizes.

It's important to note that just because a TV accepts HDR, doesn't mean it can do anything with it. Without local dimming and technology to show wider colors, HDR and WCG won't look much (if any) different than non-HDR/WCG content. Certainly not compared to a TV with HDR-compatibility AND local dimming (or OLED). We will see companies (most recently Sony) touting HDR compatibility in 1080p TVs, but this is like having a speedometer that goes up to 200 mph in a Kia. Just because it's there, doesn't mean you can use it. So be wary of this kind of misleading marketing.

So while a budget HDTV with HDR seems like a cool idea -- and is theoretically possible -- it's not likely to actually happen. Oh, well. With the prices always falling on Ultra HD "4K" TVs, it's time to embrace them.

Got a question for Geoff? First, check out all the other articles he's written on topics like why all HDMI cables are the same, TV resolutions explained, LED LCD vs. OLED, and more. Still have a question? Tweet at him @TechWriterGeoff then check out his travel photography on Instagram. He also thinks you should check out his best-selling sci-fi novel and its sequel.