Can old TV shows be converted to HDR?

There's something your favorite old TV shows have in common. "Star Trek," "Dallas," even "M*A*S*H" were all shot on film. This may seem old-fashioned, but film was actually a great way to record content.

In fact, even in the 21st century, film still has better resolution and dynamic range than 1080p HD.

Today, with high dynamic range (HDR), it's possible to get the best picture quality yet on your TV at home. You can't, however, just watch those old shows and expect to see a difference. You need special HDR content to make your HDR TV look its best. So the question becomes: can old shows really be made into HDR?

Turns out, yes, actually.

From pipes to eyeballs

Believe it or not, the TV you've been watching your whole life has been "dumbed down" compared to what was originally recorded/filmed. I don't mean its intellectual level (that's a whole different debate). I'm talking about the color and dynamic range -- the difference between the brightest and darkest parts of the picture -- you've experienced on cable, satellite and broadcast. Even DVD and Blu-ray were only a portion of what was originally captured.

To get a show from a TV studio to your eyeballs takes multiple steps, but we'll reduce them to three: The camera, the transmission medium (cable or satellite, say), and of course, your TV. Imagine each step as a pipe.

The camera "pipe" is the largest. A lot of information can be captured. Lots of color, bright highlights, and so on. Producers and directors, generally, want to record their content in as high quality as possible.

Cable and satellite providers, though, have different priorities. They don't want to store it, or transmit it, at maximum quality. Instead, they want to keep the amount of data per show as low as possible. They have limited bandwidth, and they want to maximize the amount of content.

The result is that this big camera pipe gets squeezed down to fit into the transmission pipe, which reduces color quality, dynamic range, and so on.

Your TV, up until recently, was a similarly small pipe. It couldn't display all the colors and range of the original source, so there wasn't much reason to change anything. So even though most film stocks have vastly more dynamic range, color, and resolution than what your TV could do, it didn't really matter since no TV could show it.

But now, your HDR TV is a much bigger pipe than the transmission. Now it's big camera pipe>little transmission pipe<big TV pipe<your eyeballs. The need for more HDR content is unquenchable. HDR content is what makes the whole thing a "big pipe" so to speak.

New HDR content is being made all the time. That's separate. Using HDR cameras is easy. It's the old non-HDR shows that represent the vast majority of all available content. Back in the day you watched these shows on a 4x3 standard definition TV. If you were lucky, it'd have something approaching Rec. 601 color, far less than HD's Rec. 709 and way less than wide color gamut. Along the same lines, even though it was likely a CRT and had an excellent black level, it wasn't very bright. Even the worst of today's TVs are many times brighter.

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Since the classic shows were recorded on film, or more recently high-quality video, these shows can be remastered to show that extra range. Potentially greater color too. With 4K Blu-ray and HDR streaming services, you'll be able to see these shows looking better than you ever remember. Not, of course, as vibrant and detailed as new 4K HDR shows shot on 4K HDR cameras, but better than what you saw on your old 4x3 CRT, and better than the last time the same show came out on DVD or Blu-ray.

Real-world exceptions

What I've presented is an ideal case. The above is true, but not always. Some shows were shot on cheap video. Some shows were shot on cheap 35mm film. Many weren't stored on a medium that preserved the extra picture information.

For example, if a show was shot on film, but stored on basic video, all that extra data is gone. Just as it's possible for good 35mm film to look better when viewed on a 4K TV than a 1080p TV, cheap 35mm film might not offer any (or as much) visual improvement. The same is true of improvements, or not, with HDR.

Also, not every show will, or will be able to get this remastering treatment (and it will require remastering). Some shows were shot on video, and while broadcast quality video recordings are potentially better than what you got at home, the difference is far narrower. So it might not be worth the effort. Then of course there are the fondly-remembered-but-not-big-name shows. Sure, I'd love to see what an HDR "John Larroquette Show" would look like, but it was shot on video and… it's not exactly a big draw.

Then you have shows like "Babylon 5," which was shot on 35mm, but had its special effects done in 480i video to save money. This mismatch will be even more noticeable if the show is ever done in HDR.

Remaster/conversion

So let's say there's a desire to convert to HDR. There are two ways to get HDR from old content: manual, and automatic. Manual, as you'd expect, is a colorist going through scene by scene or shot by shot and making sure the new HDR image stays true to the original. Better than the original, ideally, but most importantly, not wrong.

The other is more of an automatic process. Computer software takes a look, and determines how each scene should look given the nature of the content. Most likely, though, a combination of both methods will be used.

Technicolor is one of the companies offering this kind of software, which we talked about in "Technicolor punches high-def video into higher dynamic range."

Making HDR lemonade from SDR lemons

But what about the shows that didn't, for whatever reason, have a higher dynamic range, even in the originally shot content? Companies are working on ways to convert SDR -- standard dynamic range, which basically means any content that's not HDR -- content to HDR, without messing around with the original film, video or anything else. B<>com, for example, has software that "exploits high dynamic range of the target display while carefully preserving the artistic intent of the source SDR video." As in, they make HDR out of SDR content.

This is likely going to be rather controversial. After all, with the other methods we've discussed, we're just seeing more of what was shot originally. Ideally, the conversion is done with someone involved in the original, or someone with a keen eye to do their best to match the director's intent. B<>com's software, however, is flat-out creating something that wasn't there. They're changing the original.

Technically, this isn't that different from upconverting 480i to 1080p (or 4K). New pixels are being created either way. With HDR upconversion, however, the result could drastically change the look and feel of the content perhaps in a way not intended by the original creator, despite the company's promises.

The sad fact is, though, if it's cheap to do, and companies see a way to make profit on it, they'll do it regardless of the creator's intent. 

If you've got an HDR TV, and are a bit tech savvy, you can download some 4K HDR clips converted from HD at isovideo's website. They're another provider of conversion software/hardware.

The worst case: fake HDR made by your TV

What you may have seen already, and will likely see even more of, is HDR conversion inside a television. As in, the TV does it itself. This is likely the worst looking of any conversion. It's not possible for a TV manufacturer to put in the processing prowess needed to do this as well as even the aforementioned automated methods. The result will often look worse than the original SDR version.

Use at your discretion.

Bottom line

To make your HDR TV look its best, you need HDR content. There's still not that much HDR content, especially compared to the decades of "SDR" content out there.

It's possible that older TV shows (and movies, for that matter) have as-yet hidden range of picture quality that was unused because the TV medium up to this point couldn't take advantage of it. With HDR, that can now change.

It's going to take some work, though, either by a computer-assisted human, or a human-assisted computer. There's no way to say what shows will look better in HDR until we see them. Even a show that seems to have potential (shot on film, stored on film), might not get the love it deserves, and a mediocre conversion leaves us with something that looks no better than SDR.

It's an interesting time for HDR, not unlike the early days of HD. There were lots of methods to show SD content on HD channels, and many looked terrible. Hopefully the industry has learned from that mistake and we'll get some good-looking HDR conversions right of the bat.

Maybe.

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.