What makes HD....HD?

[HueyFilms]

This may be a simple/stupid question but I as I delve further into the roam of HD ive started wondering, exactly what is hd?

Is it only a matter of resolution, or is it a certain type of chip-set?

I'm very curious

[ProfessorU]

It is a resolution measurement. SD is usually considered anything up to 720x480, HD is higher.
The ccd/cmos in the camera are specific to HD, too.

Should be careful with the noob questions. ;) Don't forget to check 'search'

[HueyFilms]

I know its a noob question but I've noticed that there are plenty of people on this forum who seem to just not really get it....

I did actually answer my own question by looking up HD on wikipedia...

I ask because I think a lot of people here HD and don't really know what it is, but there is so much hype about it they have to have it for the sake of having it (Thats what happened with me)

The article on wikipedia is very informative http://en.wikipedia.org/wiki/High-definition_video

[ProfessorU]

I think 99% of anyone who spent $10,000 for their first day using the HVX200 probably has at least a rudimentary understanding of HD.

[HueyFilms]

I think you'd be suprised ;)

[Luis Caffesse]

To be fair - have you ever tried searching for 'HD' using the search function?
Doesn't work too well.





Sorry - no matches. Please try some different terms.

The following words are either very common, too long, or too short and were not included in your search : HD

[ProfessorU]

Hmmm, I guess I never thought of that.
Google has an excellent definition search option
just put
define:HD (or whatever else)
in the search box

[HueyFilms]

Yeah, before posting this I typed in "HD" also "High Def" and "HD Resolution" all of them yielded results other than what I was looking for.

Google got it though, no worries.

[Joe Kocsis]

this thread made me LOL!

[Arson]

HD stands for Hard Drive.

[gunleik]

OK, I'll give it a stab as this is a VERY legitimate question IMHO

HD, as of today is actually... nothing very specific, as opposed to SD

So I'll start there:
SD is a 720 x 576 (PAL) or 720 x 480 (NTSC) pixel TV image which is displayed interlaced. There is a big "debate" as to how many of these lines and pixels are effective or real, and one could argue something like 320x180 (or even less) effective pixels for a 16:9 image displayed on a 4:3 SD TV.

Still the SD standard is pretty clearly defined compared to HD. And any SD camera I know of relates to these specs, independently of recodring format, be it digibeta, DV, hi8 or even VHS -;)

SD is pretty coherent as an description for a recording, editing and display format as to technical specs.

Whearas HD...:
Let's start on the Easy End and define HD as TV-broadcast specifications, because beyond that you're basically free to add as many pixels in any aspect ratio you can eat... By some, these formats are reffered to as "ultra HD", starting with 2k, even though the pixel-spec for 2k is a close resembling twin to 1080p...

I'll start on the display side:
One currently have 2 "standard" HD "sizes"
1920 x 1080 (by some confusingly dubbed "real" or "full" HD), called 1080
1280x720, called 720

720 is always described as a progressive format, while you have both interlaced and progressive descriptions of 1080 (which I've always found very confusing, as none of the panels capable of actually displaying 1080, are interlaced afaik...)

So what do you watch this on?
As of today, either a computerscreen or pretty much nothing at full raster....

And we all know that computerscreens suck for watching and check'ing TV-images...

There are panels, but they are few and expensive or realley bad...


Then to the recording side:
Please name one of the common recording formats that complies to the specifications, except HD-CAM SR...

Right!
These days there are some fullraster formats pop'ing up, most noteworthy (IMHO) are SI's solution when recording fullraster to Cineform. Panasonics AVC-I looks very promising, too.

But the "common" formats, like: DVCPRO HD, HDV, HDCAM (not SR) all record til less than fullraster. (which sorta makes kinda sense as none or very few displays can display anything like fullraster) -;)

So I'll quickly wrap up:

Currently HD is pretty-much any video-signal with higher pixelcount than SD, up to 1920x1080.

Makes sense? Right?
Not!


Gunleik

[HueyFilms]

Great post Gunleik, very informative- thanks.

Huey

[Sam Davies]

HD stands for Hard Drive.
HDD stands for Hard Disk Drive - people sometimes shorthand that by just saying HD (but they shouldn't).

HD, in this context at least, means High Definition.

And while I agree with most of what gunleik says (and was interested to learn some of it, thanks mate!) I find that HD is split up into to fairly firm standards, 720 and 1080. I have heard there are some in-betweens, but none that I have ever seen taken seriously.

720 is always Progressive (AFAIK), but as above, 1080 is both 'i' and 'p'.

But, yeah, to answer your question as simply as it was stated - HD is about resolution, yes. There are plenty of codecs and formats used for HD, but as far as I'm aware everything called HD is done so because of its resolution.

[gunleik]

The specs (as for TV) are seemingly quite firm, trouble is that except for the abovementioned formats (SI/HDCAM SR/AVC-I) none of the common formats actually record the pixels that are specified.

And the p/i confusion just adds to the soup.

DVCPRO HD 1080, is 1440 x 1080 in PAL, and 1280 x 1080 in NTSC land
HDV/XDCAM/HDCAM IS AFAIK 1280 X 1080
etc, etc, etc

The point is that all SD recording formats I know of relate to the full raster full image, some doing it better (like digibeta) than others (like hi8 -;)

HD is so much in its infancy, that very few recording devices or panels are actually capable to show the image the "standard" describes.

I mean, someone must have had a plan to roll out 1080i panels, as this is part of the specs (a really bad idea btw), but so far noone has bothered.

But lots of cameras still record to this more or less useless format.

This kind of mess will end, but at the moment...

And then we could go on to rants about compression techniques -;)

Cheers!

Gunleik

[ramuno]

2K and 4K resolutions are still in the HD disussions. Maybe, in the future, they will get their own generic description "Super High Definition" or some other name?

For now, I include them in the HD category which means the top resolution of HD, in my mind, is not 1080.

[frubsen]

I mean, someone must have had a plan to roll out 1080i panels, as this is part of the specs (a really bad idea btw), but so far noone has bothered.



HD CRT television native resolution is 1080i.

[gunleik]

Yes, I actually know that -;)

But AFAIK they weren't many and not generally available (some sit in high-end studios) AND all HD-CRTs went out of production the last year, and noone are making them even for the studios to grade on anymore. The reality is plasma/LED/LCD and all of them are progressive in nature.

Thus I stand by my statement:
A really bad plan. But I could modify myself to: Not really available...
Shooting 1080i gives you de facto nowhere to screen your material as shot.

AND

1080i has a dataflow = 720p

I'd rather use 720p and have the option to get p stills any day -;)

As for TV, in EBU-land they have decided to go with 720p 50 ---> 1080i 50 ---> 1080p 50

The only reson I can see for this route, is to try to prove that internet will not kill TV as we know it (high datarates) and to give the panel makers a nice little upgrading route over the next few years.

And I've said enough about the i50 step....

As of now, the encoding is still the biggest concern for quality, NOT pixels.

So I stand by my claim:
For NOW, HD is not even close to being a "standard", but more of a not too well defined "common goal"

On the camera side, one could do a rather interesting comparison to the more mature SD standard.

Almost all SD cameras have imagers with substantially HIGHER pixelcount than what the standard specifies (even most DV cameras) so that the image is not diminished too much after filtering and treatment before recording.

In HD-land very few cameras even have imagers in a 1:1 number.

I don't doubt that the HVX "really is 2k internally", but I don't care too much either...
I know its images look better in 1080 than 720 and that I get a less noisey 1080 image out of the component port than through firewire, but compared to SD technology, it is still fair to say that the image is upsampled through pixelshifting.

Mind you, I really like the cam, but again, compared to how SD cameras make their images...

SI have made much halo by using "actual" 1080 chips, but still have to lose info in the filtering process.

Viper has taken the SD approach (and thus a lot of stick from Red and others): starting with higher rez sensors and downsampling them to 1080 (or is it 2k?)
But technically, I think this will be the way to go in the future. But who can afford a Viper anyway?

As to Red, Dalsa et al, I have a Red on order, but that doesn't change my rant or make me really believe I'll screen a lot of material in 4k the next year...

And I don't think my lovely 42" Pioneer plasma will be able to screen even 1080 anytime soon...

I really like it, though. It just isn't 1080.

This goes for all things HD:
I really like it. It's fun. And it's the futur, BUT:
Generally spoken, HD as of now is pretty much comparable to SD in the late 1940's.
We know where we're going, we just haven't really seen it yet.

Cheers

Gunleik

[PaPa]

are you perhaps asking the difference between HDV and REAL HD ?

[gunleik]

so what is "real hd?
Strictly spoken, only hdcam sr, at the moment...

Edit:
If you take into account ALL aspects of the standard. (Pixels, colour, framerate)

And even when recording HDCAM SR one could argue that what is recorded doesn't "really" meet the specs, depending on whitch camera you record from.

G

[HueyFilms]

I had a feeling this was a very gray area topic....

[andypaintguns]

delete this immediatly

[HueyFilms]

delete this immediatly

ehh?