If 720 and 1080 are HD..
 

...then what defines HD? Why not just cram a ton of pixels into a 640x480 and make it HD? I know it's a dumb question, but I had to ask it.

j i m

There are 2 HD standards set by the IBU(?) One is 1080, the other is 720, so that's the official line. There are those that call 720 extended definition though, as it's only a smallish jump up from SD (particularly if you come from PAL land).
Steve

My understanding is that 720p and 1080i are HDV, 1080p is HD. In my experience, and I have a fair amount in the HDV world, 720p is slightly better, resolution-wise, than 1080i. Of course, someone will disagree, it's not my intent to start a format argument, simply from a technical standpoint.

To break it down further, since the designations are ambiguous, 1280x720p and 1440x1080i are HDV. 1920x1080p is considered HD.

Hi there, please see link regarding different HD Formats and applications.

http://www.videoscope.com/pdf_files/...mats_Guide.pdf

Anything with 720 lines of resolution or greater is considered HD. There are many flavors, HDV is a compression method, just like MPEG-2

If you squeezed more pixels into it then it wouldn't be 640x480 anymore. ;)

HDV is HD just like DV, VHS, or DigiBeta are SD. They are formats based on standards. For example, HDV, HDCAM, and XDCAM HD are all 1440x1080. The "true HD" tag that I've seen floating around a lot recent is just a marketing gimmick.


-A

There are no dumb questions here, Jim.

The term "640x480" itself is an expression of a number of pixels. By doing the math (640 times 480), you get 307,200 pixels. If you cram in more pixels, then it's no longer 640x480. For example if you cram in 614,400 more pixels, then you get 1280x720, which is defined by the Advanced Television Systems Committee as HD.

Sorry Bill but that's incorrect. All of those resolutions are HD. 1920x1080 is just the maximum resolution HDTV allows (any larger than that and it's no longer HD -- it becomes UHD or Ultra-High Definition, but that's another subject).

In addition to being HDV format resolution, 1280x720 is also a DVCPRO HD format resolution. Likewise, in addition to being an HDV format resolution, 1440x1080 is also an HDCAM format resolution. Point being that HDV isn't any "less" HD than DVCPRO HD or HDCAM. The fact is that they're *all* HD, up to 1920x1080. Beyond that, it ain't HD anymore but something else.

HDV is as much of an HD format as HDCAM or DVCPRO HD. In other words, HDV isn't any "less" High Definition than any other HD format. Try not to get hung up on numbers or marketing gimmicks. The Advanced Television Systems Committee defines 720p, 1080i and 1080p as High Definition.

All of this is as defined by the ATSC. These are facts -- opinions have nothing to do with it. These are standards. There's nothing to argue about or disagree with here. Hope this helps,