[mythtv-users] OT: 3D TV

Daniel Kristjansson danielk at cuymedia.net
Mon Jan 11 22:32:51 UTC 2010


On Mon, 2010-01-11 at 19:14 +0000, Nicolas Will wrote:
> We better get used to the glasses, they will not go away. Systems
> without glasses can be seen here and there, but the system that
> separates the images for the left and right eyes is very imperfect and
> is very limited in the angle of vision before it gets ugly and you get
> sick. Optics and physics are so that not much can be expected there;
> stereo requires a clean separation of both images.

I worked on the eye tracking for one no-glasses display. It only worked
for one person at a time and the screen had to be pretty thick. It
worked on the shutter principle, it just moved the zones in the LCD
in front of the image plane so that through persistence of vision you
didn't see the big black stripes that prevented one eye from seeing
an image meant for the other. We still needed a non-polarized image
plane, so we used DLP projection. When I left the project they were
working on a screen that would work like a lenticular so multiple
people could see stereo, that technology relied on many projectors
so you would only see it applied in heavy corridor on street
advertising or a data visualization room (for oil/mineral prospectors).

Stereo in a TV or theater screen will always cause additional eye
strain for most people. There is great variation in the distance
between people's pupils. By necessity these systems must pick some
average distance. So for some people the stereo will appear flattened
and for others it will appear too deep. It's like an aspect ratio
problem except every individual has a different one, so you can't
possibly get it right if the output is to be viewed by more than one
of the world's six billion inhabitants. In practice this imposes
limitations on the cameraman, just like pans in 24 fps film must be
slow -- you must keep all the action at a distance, with no prolonged
closeups, when filming stereo. So it may be great for football, golf
and some types of nature shows, but you wouldn't want to see a drama
or romantic comedy in stereo.

I don't see any multi-person non-glasses technology happening in the
home in my lifetime for TV. It's not impossible to do, but you would
basically require us to produce LCD sized screens with virtually no
defects in CPU grade process, and get all at heat away from the
substrate and have energy be cheap enough that pumping a few kilowatts
into the TV would be a trivial thing. When you have that in place, you
just generate a hologram*. I think if you want to see that you need to
spend your time/money on cheap safe and practical in-home fusion
reactors, the display tech and many other wondrous things will
follow. ;)

*Yes there are zoned stereo screens out there, but if you use one
for about 10 minutes you'll be wishing for those glasses back so
you can say lean back in your chair once in a while, and they don't
scale to letting a family watch something together.

-- Daniel



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