Gimme some o' that!

December 27, 2008 6:54 PM

Why does HDTV look so good in the ads?

So, I'm watching a Comcast commercial about HDTV. They are showing a television running in HDTV and I think to myself, "WOW! That picture looks great. The color is awesome, the clarity is fabulous, I should really save my nickles and get me some o' that!"

But wait. I am watching this great picture of HD on my crappy-ass 14 incher and I dont have HDTV. Why, then, does it look so good? If a picture of HD looks that great on my regular TV, why dont they just make my regular TV look like it did when they showed me HDTV?

posted by Acacia to technology (6 answers total)

Maybe they're degrading the rest of the picture (the area outside of the HDTV in the commercial) to heighten the effect.
posted by nitsuj at 7:16 PM on December 27, 2008

Optical illusion. When you see a TV on TV, you expect to see the picture on that TV look worse than the picture on your own tv. Your brain is correcting for the picture quality of your TV. When you see the HDTV, it is noticing the difference between what it expects and what it actually sees.
posted by gjc at 7:17 PM on December 27, 2008

I've started, and discarded, six answers now.

You're not seeing what you think you're seeing.

They are playing with the video in such a way to make you think that the television on the screen looks better than you expect. The "you expect" part is key. Perhaps they're lowering the quality of the other video in the commercial; perhaps they've worked out a hack to play with the interlacing on your tv. I'm absolutely *certain* that they're desaturating the non-"HD" portion of the video so that the colors from the HDTV "pop" more.

As for the sharpness. The biggest thing is probably that the television you're seeing on the screen isn't taking up your whole screen. If you shrink anything, it looks sharper. If you have a 100x100 pixel display, and you scale down a 1000x1000 image, it's going to look just *awesome* (no pixelation, for instance). But there's physically less information available. If you get in close enough, you may discover that the Mona Lisa has no eyeballs, for instance.

Next, making your SD look like HD...

Not possible. In order for Scully and Mulder to look "high def", you'd have to pull the same shenanigans. Shrink it so that it only takes up, say, 70% of your screen. Put a border around it, and desaturate that. But, no matter how different it looks, we haven't added information, we've subtracted it. We disappeared some pixels to make it fit in 70% of the screen.

Now, you *can* get a better picture from your television by purchasing HD content and then downscaling it. It's going to look way better than something originally shot for SD. Why? Because there's WAY more information in the initial video stream, so when when we downsample it, we still reap the benefits of that higher information density.

I'd actually say that this last point is perhaps the more powerful one. If you take two identical videos, one with an SD video camera, and one with an HD video camera, and then downsample the HD version to SD, it will look better. This is because the SD video stream itself is set up for SD televisions, including all sorts of quality-destroying effects like interlacing. Perhaps you're seeing nothing more than a commercial filmed in SD with a window or HD inserted into it. The contrast between the two is what's convincing you that you're seeing a better picture, rather than an actual better picture.

But, in essence, Comcast is fooling you. You aren't seeing a better picture. There is no more information in a frame of the Comcast commercial than there is in a frame of Starsky and Hutch.
posted by Netzapper at 7:40 PM on December 27, 2008 [5 favorites]

I don't know the specific ad, but they could also be using better, sharper, highly saturated and contrasty source material. By doing so, they create an approximation of HD when compared to other ads and content that are not created specifically to "look good."

Also (and someone with better technical knowledge will surely correct me) I think something created in high definition may look better than the same thing created in normal definition, when shown on a regular screen. The first time I watched Enron: The Smartest Guys in the Room, from a regular DVD on a regular DVD player, and on a regular TV, the picture clarity was noticeable. I found out later it was produced by HDNet, and filmed in HD. Maybe I just liked the cinematography, so I'd be interested in some scientific answer as well.
posted by Fuzzy Skinner at 7:45 PM on December 27, 2008

Also, what was the content they chose to put on the HDTV in the commercial? Was it full of blues and violets? Was the background or letterboxing black? Blue stimulates the eye more strongly than longer-wavelength light; black increases contrast for bright backgrounds.
posted by Netzapper at 7:47 PM on December 27, 2008

Audio plays an element also. Heighten the high frequencies and it convinces your there's more clarity. And audio CAN make you think you're seeing more too.

I work in the industry, and know what goes on behind the scenes of commercial production. First, Standard Definition TV can look beautiful. If you look at digital tape on a professional grade monitor (just a well made TV) you'd be surprised at how nice things will look. But most people's TVs aren't made with all the best parts...

But before it even hits your TV, even if you bought a nice one, it goes through some terrible things. Most TV commercials are delivered on BetaSP tapes, the professional brother of BetaMax. This is the product that competed and failed against VHS. Yes, it's better than VHS, but it's still not even close to DVD quality, and most in the industry know even DVD quality isn't great. The stations themselves make tape transfers, which suffer generation loss. Some stations use old, crappy, unmaintained equipment, which makes things worse.

So while there's a few good answers above already, I just wanted to add some of my knowledge. It's possible that the commercial you've seen has just taken precautions to avoid some of these short falls. It's also likely they've done the visual trickery discussed above.

All that said, my new HD does look beautiful. I would say it's certainly worth it if you NEED a new TV. Worth it if you spend a lot of time in front of the tube. Might not be worth it if you're having to be inspired by commercials.

Oh, one more thing. Before my old TV kicked the bucket, I bought one of those digital converter boxes. I must say, just the over-the-air digital signal on my old TV was far superior to what the cable company was sending down the line. So you should definitely consider the source.
posted by toekneebullard at 2:50 PM on December 29, 2008