🚀 go-pugleaf

In article <5461@bgsu-stu.UUCP> searcy@bgsu-stu.UUCP (todd Searcy) writes:
>
> Have anyone heard about a study put out by the M.I.T. Media Lab
>concerning people perception of HDTV?  The study stated that relatively
>speaking, people can not tell the difference between HDTV and NTSC.

>I have seen HDTV and I`ve seen NTSC.  Believe me there is a big difference.
>Or is there? :).
>Or is there? :)    Thanks again. Searcy@barney.bgsu.edu


There is a difference between NTSC and HDTV - if you sit close enough
to the screen.

NTSC television is intended to be viewed from a distance of about 10
times the picture height.  At this distance, one scanline pair is about
1.5 arc minute high as seen from the viewer's eye - not bad,
considering that the eye's resolution limit is around 1 arc minute.
The horizontal luminance resolution is somewhat worse than this, and
horizontal colour resolution again worse.  Still, an off-the-air NTSC
signal (or one from a video disc) displayed on a good NTSC monitor will
look pretty close to sharp when viewed from 10 times the picture
height.  At that distance, a HDTV picture will appear wider, but not
much sharper.

However, HDTV is intended to allow you to view from about 3 times the
picture height.  At that distance, the resolution difference between
HDTV and NTSC will be readily visible.  (HDTV has only about twice the
resolution of NTSC, so I can see where moving up to 5 times picture
height is justified, but not 3 times).

To really compare NTSC and HDTV side-by-side, you need to use an HDTV
screen that is 2-3 times as large as the NTSC one, or place the HDTV
screen a factor of 2 or 3 closer to the audience.  You want to
demonstrate how much larger an HDTV image can be and still retain
acceptable sharpness, not that HDTV looks sharper at "normal" viewing
distances.

I've seen a NTSC vs. HDTV demo put on by the CBC that suffered from
just this flaw.  Both CRT's were located in the same plane, so the
viewing distance was the same for both.  The NTSC image was actually
slightly larger than the HDTV one, and most of the audience was far
enough away from the screens that the resolution difference was not
very significant.  In addition, the NTSC set was brighter than the HDTV
one.  Thus, it's not too surprising that I preferred the NTSC image
half the time or more - not what the demo was intended to demonstrate,
I'm sure.

	Dave Martindale