Digital Video

On Sat, 19 Jun 2004 21:25:38 -0700, Big Bill wrote:

On Sat, 19 Jun 2004 18:20:03 -0300, "Duram" wrote:

Is there any digital video camera that records videos
in a 800*600 pixels resolution or more? the maximum
I found until now was 640*480 pixels resolution.
I need that for high quality DVD recording films.

Here in the US, we use NTSC (Never Twice Same Color).
NTSC is 740x480; my video camera does this.

Actually, NTSC is analog, it's not based on pixels, but on analog
transitions. DV and DVD have selected 720x480 (not 740) as how they're
like to represent standard definition video. High end digital title
generators for analog gear often go to 1400 or 2000 pixels across.

Here's the difference: a digitally based video output can resolve some
exact number of pixels, such as the 720 mentioned. These show up on
analog sets as precise transitions in the analog frame, and they're
slow enough to work well with television (though it's quite possible
you'll not get all of the information on a plain old NTSC set).

But a pixel and color change can occur ANYWHERE on the analog scan
line. The analog limit is bandwidth, which is expressed as "where can
the next change occur". You can make nice, smooth edges with a
2000-pixel titler, but you can't actually display 2000 pixels across.
After a pixel changes, you'll have to wait awhile for the next change.
That's a simplified explanation of the analog limits.

Recording to DVD, you can't use more pixels than the TV will display;
the fact that all the cameras where you are use 640x480 would lead me
to believe that's what the TVs use.

Nope. 640 x 480 is basically a popular approximation of a
representation of "TV resolution" in digital form, using square
pixels. TV's don't use square pixels, which is why your 720x480 fills
that 4:3 format on SD sets, and the same 720x480 will fill the 16:9
format on a widescreen set.

VHS and DVD both use 740x480 with NTSC; it's the compression level
that accounts for the difference in quality.

Not even close. VHS is analog, there are no pixels. In terms of line
resolution, VHS is about 1/2 the resolution of DVD. It's DVD's digital
color and higher bandwidth that account for the difference in quality.
Compression is simply necessary to fit all of that perfect digital
video using today's cheap storage media.

Assuming that you have a decent video camera, the number of pixels is
only relevant for some features, not for the actual quality of the
output.

Unless you have an HDV camcorder, you probably have no control over
the pixel count of the medium. Your imager, perhaps, but yeah, for
camcorders, it's nothing to worry about.

In other words, the same camera will give you a video file that can be
processed to both DVD quality and VHS (or other) quality. (it's in the
editing software where this is determined)

Well, if you shoot in DV, you probably want to run an NTSC color
filter before output to VHS.

Dave Haynie | Chief Toady, Frog Pond Media Consulting
| Take Back Freedom! Bush no more in 2004!
"Deathbed Vigil" now on DVD! See http://www.frogpondmedia.com

On Wed, 30 Jun 2004 17:50:41 GMT, (Dave Haynie)
wrote:

On Sat, 19 Jun 2004 21:25:38 -0700, Big Bill wrote:

On Sat, 19 Jun 2004 18:20:03 -0300, "Duram" wrote:

Is there any digital video camera that records videos
in a 800*600 pixels resolution or more? the maximum
I found until now was 640*480 pixels resolution.
I need that for high quality DVD recording films.

Here in the US, we use NTSC (Never Twice Same Color).
NTSC is 740x480; my video camera does this.

Actually, NTSC is analog, it's not based on pixels, but on analog
transitions. DV and DVD have selected 720x480 (not 740) as how they're
like to represent standard definition video. High end digital title
generators for analog gear often go to 1400 or 2000 pixels across.

Here's the difference: a digitally based video output can resolve some
exact number of pixels, such as the 720 mentioned. These show up on
analog sets as precise transitions in the analog frame, and they're
slow enough to work well with television (though it's quite possible
you'll not get all of the information on a plain old NTSC set).

But a pixel and color change can occur ANYWHERE on the analog scan
line. The analog limit is bandwidth, which is expressed as "where can
the next change occur". You can make nice, smooth edges with a
2000-pixel titler, but you can't actually display 2000 pixels across.
After a pixel changes, you'll have to wait awhile for the next change.
That's a simplified explanation of the analog limits.

Recording to DVD, you can't use more pixels than the TV will display;
the fact that all the cameras where you are use 640x480 would lead me
to believe that's what the TVs use.

Nope. 640 x 480 is basically a popular approximation of a
representation of "TV resolution" in digital form, using square
pixels. TV's don't use square pixels, which is why your 720x480 fills
that 4:3 format on SD sets, and the same 720x480 will fill the 16:9
format on a widescreen set.

VHS and DVD both use 740x480 with NTSC; it's the compression level
that accounts for the difference in quality.

Not even close. VHS is analog, there are no pixels. In terms of line
resolution, VHS is about 1/2 the resolution of DVD. It's DVD's digital
color and higher bandwidth that account for the difference in quality.
Compression is simply necessary to fit all of that perfect digital
video using today's cheap storage media.

Assuming that you have a decent video camera, the number of pixels is
only relevant for some features, not for the actual quality of the
output.

Unless you have an HDV camcorder, you probably have no control over
the pixel count of the medium. Your imager, perhaps, but yeah, for
camcorders, it's nothing to worry about.

In other words, the same camera will give you a video file that can be
processed to both DVD quality and VHS (or other) quality. (it's in the
editing software where this is determined)

Well, if you shoot in DV, you probably want to run an NTSC color
filter before output to VHS.

Dave Haynie | Chief Toady, Frog Pond Media Consulting
| Take Back Freedom! Bush no more in 2004!
"Deathbed Vigil" now on DVD! See http://www.frogpondmedia.com

The OP was asking about *digital* video cameras.
The answers fit what the OP asked.

Bill Funk
Change "g" to "a"