So Just What IS HD?

[Rob Babcock]

It's a myth that HD is "in the eye of the beholder" somehow. HD is a legal definition. Period. To try to confuse the issue with discussions of screen size, etc is to obfuscate the issue, IMO. If your display can resolve the full resolution of a legally defined HD signal, it's HD.

Of course, if your screen is too small, if you sit too far away, if there's Vasoline smeared on your glasses...yes, all these things will prevent one from appreciating the majesty of HD. I say this not to be a smart-arse, nor to be mean, but to clarify the issue. Many manufacturers use similar smoke screens to try to sell any DTV as HD. It's very important to "keep our eyes on the ball," and be clear about what real HDTV is.

 

[MarkOcena]

HD concept vs definition

Both of you guys are right. I think there should be a definition for 'HD' in terms of resolution at least, otherwise there is not really other empirical way to compare the basic capabilities of TVs. On the other hand, resolution is not to be the be all and end all for TV comparison as there are too many other factors that effect picture quality. It is, however, one of the bigger factors. Obviously if one TV doesn't have a specific resolution capability then there isn't too much more that can be improved on. Right now, the term HD basically just refers to 1080i or 720p, which only refers to vertical scan rate. A complete, 2-D, representation of resolution would be a good start for a real explanation of what HD refers to.

It is debatible, though, if what we are calling HD right now should be called that in the future. It might be just TV intead of HD-TV, which I think as someone mentioned earlier, would be history repeating. So maybe a more succinct term is required to describe a higher quality TV system, but not necessarily the best quality you'll get (depending on where you sit from the TV).

 

[BMXTRIX]

The issue is that the industry is reusing a term that was used to describe NTSC many a year ago when it debuted.

Now we consider NTSC (480i) 'regular' tv. Then we go around talking about our HD sets, which may have 768 lines, or 1024 lines... But, everything is SCALED TO FIT! We call it 'true' hd... Even though it rarely is 720p native... and next to never is it 1080i native.

I'm not proposing a definition - I'm repeating what the definition is. The industry is, on the other hand, trying to convince you, that 1080i is HD or that 720p is HD. When all they are is part of the ATSC standards set.

What is funny - is page 10 of the aforementioned link says an HDTV will display between 720p and 1080i resolution... So what happens if you have a 1080p (better) display? Is that SUPER HDTV?

I accept the the industry has dubbed 720p and 1080i as HD. But, it sickens me that nobody knows that this term was used for 480i when it came out, and is really an ambiguous term. It is 100% measurable if you know the display size, resolution, and source. But, it changes as soon as you change one of those things. Anyone who wants to be an expert on the video side of A/V should know what HD means, vs. what the industry is dubbing it to be this day, week, or year.

30 years ago they wouldn't have believed a 1080p display was even possible. What would they have called it when 480i was already HD?

 

[Rob Babcock]

1080p is also a legal HD resolution. Adding another name for it naturally will merely obfuscate the matter even further for the end consumer. Grading it by what the native material is will also prove futile- what is film, on that scale? It's capable of more resolution than any current video device can muster.

Before there was any such thing as "hi def" as it know it now, companies were bandying about the term. How is than any different than audio? Many consider the LP "high res" audio- should we legislate that away, and make it retroactive to boot? It seems to me there's not a lot we can do about marketing pitches used in the 70's & 80's.

Again, I think a perfectly clear and emminently fair definition of HD would be than any resolution of 720p or better meets the standard. Few would say that isn't "true" HD. I'm referring to the legal standard the hardware must meet. As far as whether the network content must be produced to take advantage of that- well, that's a matter for the FCC. One would presume that when (and indeed if) Hi Def ever reaches the point of sufficient market penetration to trigger the federally mandated switchover, networks will be quick to ensure they have a competitive product out there.

Therein lies the problem: manufacturers are eager to tag products HD, but broadcasters don't want to broadcast HD til there's sufficient "installed base" to make it profitable. Consumers largely don't want to buy a new (and expensive) HD set until 1) there's something to watch and 2) they see a compelling demonstration of its benefits.

I don't disagree that viewing habits dictate the results you'll get, but I think we really have to resist the temptation to obfuscate the issue by insinuating 480i is HD at one viewing distance, 1080p is at another, etc etc. To keep the issue clear for consumers, manufacturers & broadcasters, I think it's essential to work from a definition of HD that's rooted in technical standards & regulatory codes. IMOHO, you can keep adding numbers & letters so long as they're at least 720p or better.

 

[BMXTRIX]

Ah, now I get it.

Rob, you are confusing BROADCAST HDTV to what screen HD means.

The government has defined specific broadcast standards as being dubbed HDTV. These include 720p, and 1080i. It most DEFINITELY does not include 1080p as a broadcast standard at this time. There is no question that 1080p or 2160p is better than 1080i, but at this time, it is not part of the defined broadcast standards.

What you are talking about is completely separate from whether a screen is HD.

What I have been addressing is screen resolution and what makes a television HD, not whether the broadcast to it is actually HD. These are two very separate and distinct items and issues and are not related at all. For example, just because a projector can display resolutions up to 1600x1200 pixels, does not mean that the projector itself IS 1600x1200 - it may only be 1024x768, which means it is processing the heck out of the native resolution. This affects quality and definition greatly. The same happens with plasmas and projectors all the time. Send a 1366x768 plasma 480i, 480p, 720p, or 1080i is all gets processed to show on that display. Not one of the HD, ED, or SD formats remains in it's native form.

A display showing an HD broadcast does not have to have 720 lines or more. Yet, it can still be an HD display device dependant on the size and viewing distance. This is completely separate and irrelavent to what the broadcast is.

 

[Unregistered]

So BMXTRIX contends that 'High Definition' is in th eye of the beholder - depending on how far away one sits and how good an image is perceived to be. If it looks good, then it is Hi-Def.

Sorry but what is HD or not is defined by the FCC. Its the same story as video standards for computer graphics. Would you say that Super VGA (SVGA) really isn't 'super' or that X(tended) VGA really isn't 'extended'?

Granted, as resolutions increase and picture quality improves, what is defined today as HD won't be considered HD in the future, just as SVGA isn't so super anymore. But lets not confuse one's subjective idea of the quality of an image as HD vs the legal definition of HD.

 

[Rob Babcock]

BMXTRIX, I guess is starting to sound like "if a tree falls in the forest, and no one is there to hear it, does it make a sound." In my view, a signal is flatly HD or it's not- you confuse your perception of that picture, how far you sit from the screen, whether your glasses or contacts are clean etc, with what the signal is. I think you're chasing down a blind alley. I don't recall what all 18 DTV specs are, nor whether 1080p is one of them, but again HD is a legal definition. At the risk of simply repeating myself, that's the most informative way to view HD IMO. To try to have a sliding scale of distances & circumstances where a given image will be HD under one viewing condition and not under another is simply bizarre.

Certainly one should calibrate ones set, view from the proper distance, etc. And you won't get the full benefit of HD if you don't (although the same can be said of NTSC). I think you're confusing manufacturers claims & the ability to scale images.

AGAIN- I would submit that the actual display device itself should be capable of displaying the full resolution of a "true" 720p signal. Since the FCC was "thoughtful" enought to include a dozen and a half specs that can all be considered HD & all might conceivably need displaying, a good many sets will have to scale the image (how many native rates do you suppose a fixed pixel display will support? )

If your point was that many TVs that claim to be HD are really only scaling/downcoverting HD signals to their native rate, I agree. As would probably everyone that reads this site. Is that what you mean by the screen vs the broadcast? If so, I guess maybe I did misunderstand your original post.

 

[BMXTRIX]

So you are saying a 853x480 television showing HD broadcast is flatly not HD?

Or is it HD?

The FCC does NOT define hardware - they are defining the broadcast. The FCC flatly says that 1080i and 720p broadcasts are called HD.

The perfect quote: "Its the same story as video standards for computer graphics. Would you say that Super VGA (SVGA) really isn't 'super' or that X(tended) VGA really isn't 'extended'?"

IT MOST DEFINITELY IS NOT! A 1024x768 monitor will not properly display 1600x1200, 1280x1024, 800x600, or any number of other resolutions! Why do you feel your 1366x768 FPD can be called HD when it is not 720p OR 1080i? This is total lunacy to make such a claim! Anyone (and I mean everyone here) can sit down with a LCD monitor, or their laptop, and see what happens to interpolated and scaled UXGA video when piped to a 1024x768 screen. The image goes to hell! But, step far enough away from it and it is impossible to tell. Hmmm... maybe there is something there.

Rob, a signal IS flatly HD or it is not. I agree. But you say "I would submit that the actual display device itself should be capable of displaying the full resolution of a "true" 720p signal." What in the world does that mean on a 1024x1024 plasma? Or a 1366x768 plasma? How much worse does it look on a 853x480 plasma?

You keep talking about HDTV broadcasts, which I am not, not, not talking about! I am talking about what actually makes a television HD, and it has nothing to do with the signal being sent to it. You take your 1080i signal and send it to a 1366x768 screen and to a 853x480 screen and at about 15 feet you will NOT be able to tell me which screen is which. That is the bottom line on what makes a DISPLAY HD and it has nothing to do with the HD broadcast.

The FCC defines HD as (only) 1080i and 720p. 1080i can come in a few flavors as well as 720p. A display that is 100% ATSC compliant will display (only by processing!) 480i, 480p, 720p, and 1080i. It does not have to display 1080p, and no broadcasters are using 1080p.

You say any TV that shows 720p natively is HDTV... Well, tell me which plasma shows 720p in it's native format WITHOUT processing it first. There may be one or two out there... But where does that leave 1080i? A FPD can't show both 720p and 1080i, in fact no FPD is currently capable of showing 1080i natively. It is all processed - all of it - which means that no matter how much you scream that 1080i is HDTV, what matters is the display it is being viewed on, not the 1080i that is coming into it.

 

[BMXTRIX]

Actually - let me make a quick comparison which may be easier for some to understand.

AUDIO:
You have a DVD with THX encoding, you are playing it on THX labelled audio equipment, with THX rated cables, on speakers that are THX certified.

Are you listening to true THX audio if the room you are in is all hardwood with hard floors and an open back while sitting out of the primary listening position and the speakers placed in the incorrect location?

Of course not - any audiophile will tell you that it takes more than the SOURCE being THX to make the listening experience the way THX is supposed to be. So, THX actually covers a lot more than the original source material.

Likewise, HDTV is more than the source material, and is more than the display that presents it.

Finally - if your audio room is set up for THX, it is properly acoustically treated, and you have a complete THX setup everywhere and are playing a THX source... But, your speakers are NOT THX certified... Does that mean you are NOT listening to THX audio the way it was meant to be heard?

Once again, of course not! If the speakers are of very high quality then they would be indistinguishable from their, typically higher priced, counterparts.

The same is true with HD. It is more than the display being a specific resolution, it is more than the source material. It is the combination of all factors that make the video experience HD. Just as it is more than just the encoding the makes THX an audio experience.

 

[docferdie]

"The FCC does NOT define hardware - they are defining the broadcast"
"The FCC defines HD as (only) 1080i and 720p"

I have to disagree with you there. The table on page 10 of the link I previously provided shows that a "television type" named "high definition television" has a "vertical resolution from 720p to 1080i"

This actually clearly answered the question I had in a previous post in that a display device merely had to have a "vertical resolution from 720p to 1080i" to legally have the HDTV logo in an analogous manner to the CD logo. This is why devices such as those with a pixel resolution of 1024x1024, 1024x768, and 1366x768 can legally display the HDTV logo while a device with a pixel resolution of 854x480 can not.

 

[BMXTRIX]

Apparently I stand corrected on this issue.

The CEA has made it clear that the only way you can enjoy HDTV is by purchasing a plasma priced several thousand dollars more than a 480p set (EDTV) which of course has nothing to do with marketing and sales... But, definitions. The original definition, which is now obsolete I imagine of actually looking at what you are purchasing is no longer accurate.

Feel free to spend away and know that is all the matters.

 

[MarkOcena]

Expensive TVs

I want to try putting something simply:

The HDTV logo is one way of recognizing that, when watching the TV with a HD receiver providing the signal, you will be able to get a clearer, more realistic picture without standing a long distance back like you would for a TV without the HDTV logo.

Since this is very simplified, there are factors that will make this statement less 'observable'. The fact is, when there is more picture information present, one can be positioned closer to the display then a situation where there is less information and one must be positioned further away.

I am aware that this is a vague and subjective approach, but we already saw where the discussion of exact resolution and such went. Sure, the term 'high definition' may have been used before - I don't remember, I wasn't around even when 'high-rez' vinyl was huge.

I'm pretty sure the people that have bought expensive plasma TVs didn't do so to watch it far across the room, but to instead be up close to watch and marvel at the amazing thinness, etc., with a similar quality.