On Fri, 22 Jun 2001 22:45:36 GMT, "Alexander Ibrahim"
>About National Geo..
>I ain't doubting you, it is just what they told me themselves and what I
>read in Videography. I only know you guys from here, so I have to lend a
>little more credence to those other well known sources. I hope you
>understand that.
To clarify, Nat Geo produces not only TV specials, but
a bunch of other material (kids videos, etc.). It may well be
that for the TV specials, film is generally used, but for
the bulk of their productions (overall...), video is used...
>About progressive video,
>
>Computer monitors can provide a non-interlaced or progressive image these
>days. There are also progressive TV's now, though I do not have one. Finally
>there are plenty of HD devices coming that can show progressive scan images.
>
>On any of those, frames will look better in progressive scan, because they
>have all their pixels scanned at the same time. Progressive video can look
>better too, but only slightly. A still extracted from video is actually two
>fields. A video frame is two fields, each with half the vertical resolution
>of the screen.
>
>So, those jagged edges that appear in interlaced video don't in progressive
>video, if you can display it. Instead you have clean edges. Progressive has
>a higher spatial resolution.
>
>It does not come from pixel count though, which I think is what you guys
>keep saying to me. It comes entirely from how the image is created.
>
>The problem is that most TV's can't use that. They effectively create the
>problems that are not present in the source footage.
>
>Then again, a lot of TV's can't make use of component or even y/c signal
>enhancements. That hasn't stopped you from shooting in a high quality
>component format has it ?
>
>In other words, I think we are quibling about semantics, not technology.
Yes. Basically, most video is viewed in such a way that
interlaced-mode is the preferable way, technically, to
shoot the video (TV is generally interlaced, computer-viewed
video is often deinterlaced in the process of compressing it
for computer-monitor viewing, and film transfers can use
the interlaced fields to better make the transfers...).
Shoot in the mode appropriate for the viewing method
intended (which, generally, favors interlaced-mode).
If you make an aesthetic decision that PS-mode looks
better to you, that is fine - but PS is technically
inferior for most uses (it cuts temporal [and sometimes
also spatial] resolution - hardly an advantage, for me...).
Personally, I prefer the ability of video to show sharpness
during motion, and do not value motion-blur (I consider
this a defect in film-rendition, not an advantage, so
I feel no desire to try to duplicate it in video,
especially when in the process of doing it, I would
technically damage the potential resolution of video...).
>Now, current progressive scan cameras don't impress me much, not even the
>XL-1 which is the best progressive camera until you look at DVCPRO P
>cameras. One problem is that with the XL-1 you can't combine 1/30 shutter
>and progressive scan. Adding in the motion blur of a slower shutter really
>would help smooth out the images you get in progressive.
But it would probably add other artifacts that would not be
appealing...
>Also, typical pro video use can't acommodate slower temporal resolutions. We
>need 48 frame progressive before it becomes acceptable for common ENG usage.
>60 is probably better
Yes, of course - let's all go to HDTV, non-interlaced!
We can all agree on that! ;-) But, for now, for the
majority of current uses, video shot in interlaced
mode is technically superior to video shot in PS
mode...