🚀 go-pugleaf

In article <sa0KhqO00Uh7M2R25C@andrew.cmu.edu> bas+@andrew.cmu.edu (Bruce Sherwood) writes:
>At the risk of stating the obvious:
>
>Some of this discussion of HDTV implies that there will always be a need
>for another generation of standards with even higher resolution.  That
>isn't necessarily the case.  The human eye has limited resolution, and
>higher resolution than that in the picture is literally useless, if you
>are talking in terms of a "typical" screen size viewed from a "typical"
>viewing distance.
>
>The analogy with audio is that a CD with frequency response out to 10
>MHz would not sound better than one with frequency response out to 20
>KHz, because the human ear can't hear the higher frequencies.

If you move closer to a loudspeaker, you don't need better frequency
response - your ear's limits are the same at any distance.  You can
make the same argument for colour and brightness resolution, but not
spatial resolution, in an image.  I.e. beyond a certain point, using
extra bits for brightness or colour resolution just doesn't produce
a noticeable improvement in the picture, no matter how close you get.

But the analogy is all wrong for resolution.  If you move closer to an
image, so it fills more of your field of view, you need better spatial
resolution.  And somebody will always want to sit closer than the
current standard is designed for, at least for the forseeable future.
NTSC was designed for a viewing distance of 10 times the picture
height, HDTV for 3-4 times the picture height.  I want an image that
looks sharp from 2/3 the picture height - that gives me a 90 degree
field of view (with a 4:3 aspect ratio).

What you say would be true only if there was a "typical" screen size
and a "typical" viewing distance.