3D test on Channel 4
 

I set my Topfield PVR to record a programme on Channel 4 which DigiGuide was
showing for 0405 last night (Sunday 11 October). What was broadcast wasn't
what was in the schedule but a test transmission for 3D television.

I find it difficult to take the idea of 3D television seriously, but it
looks as though somebody does!

André Coutanche

3D test on Channel 4
 

How were they doing it hough? I can recall those.. was it nintendo.. games
with fast switching lcd glasses which gave everyone a headache.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"André Coutanche" wrote in message
...
I set my Topfield PVR to record a programme on Channel 4 which DigiGuide
was showing for 0405 last night (Sunday 11 October). What was broadcast
wasn't what was in the schedule but a test transmission for 3D television.

I find it difficult to take the idea of 3D television seriously, but it
looks as though somebody does!

André Coutanche

3D test on Channel 4
 

Brian Gaff wrote:
How were they doing it hough? I can recall those.. was it
nintendo.. games with fast switching lcd glasses which gave
everyone a headache.

The pictures had colour fringes, so I assumed it was for viewing with
red/green glasses. I've kept the recording for now in case anyone is
interested in seeing it.

André Coutanche

3D test on Channel 4
 

"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo.. games
with fast switching lcd glasses which gave everyone a headache.

"Channel 4 will be using ColorCode 3D glasses, which use amber and blue
filters to produce the 3D effect."
http://www.pcpro.co.uk/blogs/2009/08...periment-work/

They claim to reproduce full colour, though I don't know how they work

I remember the old red/green glasses - the lenses were made of gelatin so
touching them made them go cloudy. You had to hold them up to your eyes and
they produced a black and white image. I think I only saw one film (Saturday
morning club at the local Gaumont), which mainly consisted of people
throwing things at the screen as I remember.

Then around 1982 ITV showed a few 3D programmes you watched through red/blue
glasses given away with TV Times - there was some colour in the image
viewed, but it was rather washed-out like early, experimental colour films.

Then more recently Doctor Who and a couple of other programmes were shown
using a system that required clear/tinted glasses given away with Radio
Times. This produced full colour, but relied on movement of the images in a
particular direction. It worked because the eye's optical system processes
dim images more slowly than bright ones.

--
Max Demian

3D test on Channel 4
 

These systems are all rubbish. Only Sky TV are doing it properly. Their
system uses glasses that are the same colour for each eye, don't need a
shutter or the associated heavy electronics in the frames of the glasses,
and shouldn't give anyone a headache. And they're getting Gucci to make the
frames so they're as much of a desirable fashion accessory as the headphones
for an iPod.

http://www.which.co.uk/reviews-ns/sky-3dtv/index.jsp

"TV manufacturers including JVC, LG and Sony are working on 3DTV sets, some
of which are due to arrive on the market in 2010. Sky said that you can
watch Sky 3D TV on a 26-inch screen, but the larger the screen, the better
the results. Does 3D TV cause headaches?
Sky blamed historical flaws in 3D TV on traditional 2D filming methods.
Depth, movement, panning and zoom all need to be considered in a new way
when shooting 3D, Sky explained, and individual shots need to last longer
than the fast-paced sequences we are used to with regular TV. When it's done
right, Sky said, you can watch hours of 3D TV without getting a headache. We
did not experience any ill effects from our time viewing Sky 3D TV".

"By pressing the 3D TV button on the remote control, the TV changes the way
the clips are displayed. In simple terms, the left camera's footage is
played on the odd lines that make up a TV picture and the right camera's
footage is played on the even lines. The two images are then polarised by
the 3D TV’s special panel so that after being filtered by the 3D glasses,
your left eye sees only the left camera's footage and your right eye sees
only the right camera's footage. As two images occupy the screen, resolution
is halved, so a 1920 x 1080 HDTV would show 3D TV in 960 x 540 resolution."

"Sky 3D TV verdict: We were all impressed by the clips that we saw, and if
Sky's 3D TV package follows in the footsteps of its high-definition
packages, it could see significant success."


"Max Demian" wrote in message
...
"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo..
games with fast switching lcd glasses which gave everyone a headache.

"Channel 4 will be using ColorCode 3D glasses, which use amber and blue
filters to produce the 3D effect."
http://www.pcpro.co.uk/blogs/2009/08...periment-work/

They claim to reproduce full colour, though I don't know how they work

I remember the old red/green glasses - the lenses were made of gelatin so
touching them made them go cloudy. You had to hold them up to your eyes
and they produced a black and white image. I think I only saw one film
(Saturday morning club at the local Gaumont), which mainly consisted of
people throwing things at the screen as I remember.

Then around 1982 ITV showed a few 3D programmes you watched through
red/blue glasses given away with TV Times - there was some colour in the
image viewed, but it was rather washed-out like early, experimental colour
films.

Then more recently Doctor Who and a couple of other programmes were shown
using a system that required clear/tinted glasses given away with Radio
Times. This produced full colour, but relied on movement of the images in
a particular direction. It worked because the eye's optical system
processes dim images more slowly than bright ones.

--
Max Demian

3D test on Channel 4
 

"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo.. games
with fast switching lcd glasses which gave everyone a headache.

It sound to me from what people are saying that this is a similar system
as was used in the early 80's for a week or so, with the two pictures
displaced
laterally much like a static convergence error and coloured spectacle lenses
used to
separate them.
This is a very unnatural way to view, because your eyes have to learn to
diverge
slightly, quite literally causing eye muscle strain. I am sure I read at the
time a
suggestion that permanent damage could result, perhaps to children's
developing
eyes, intuitively I would suspect this is a real issue.

--
Graham.

%Profound_observation%

3D test on Channel 4
 

Graham. said the following on 11/10/2009 11:26:
"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo.. games
with fast switching lcd glasses which gave everyone a headache.

It sound to me from what people are saying that this is a similar system
as was used in the early 80's for a week or so, with the two pictures
displaced
laterally much like a static convergence error and coloured spectacle lenses
used to
separate them.
This is a very unnatural way to view, because your eyes have to learn to
diverge
slightly, quite literally causing eye muscle strain. I am sure I read at the
time a
suggestion that permanent damage could result, perhaps to children's
developing
eyes, intuitively I would suspect this is a real issue.


I think the Victorian style laterally placed images with the centre of
each image being close to the average viewing centre of each eye being
the most natural (i.e., looking straight ahead). If the images are
large, say 6*4.5 standard landscape prints then what can be used is a
binocular prism or front mirrored setup at the viewing end. That's
what I've been using for years.

3D test on Channel 4
 

"Graham." wrote in message
...


"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo..
games with fast switching lcd glasses which gave everyone a headache.

It sound to me from what people are saying that this is a similar system
as was used in the early 80's for a week or so, with the two pictures
displaced
laterally much like a static convergence error and coloured spectacle
lenses used to
separate them.
This is a very unnatural way to view, because your eyes have to learn to
diverge
slightly, quite literally causing eye muscle strain. I am sure I read at
the time a
suggestion that permanent damage could result, perhaps to children's
developing
eyes, intuitively I would suspect this is a real issue.

--
Graham.

%Profound_observation%

Don't worry. The separation of the two complementary coloured images
(red-cyan or whatever) has to be adjusted at source to ensure that the
viewer's eyes are focused and converged at a comfortable distance. This is
usually arranged so that the image of the nearest object in the scene is at
or just behind the apparent window defined by the TV screen-surround. The
image displacement is not quite like a static convergence error, the
separation being a function of distance within the image. Also, since the
coloured specs have no optical power, there is no danger of mis-convergence
from the specs themselves.

TrevM

3D test on Channel 4
 

"Graham." wrote in message
...


"Brian Gaff" wrote in message
...
How were they doing it hough? I can recall those.. was it nintendo..
games with fast switching lcd glasses which gave everyone a headache.

It sound to me from what people are saying that this is a similar system
as was used in the early 80's for a week or so, with the two pictures
displaced
laterally much like a static convergence error and coloured spectacle
lenses used to
separate them.
This is a very unnatural way to view, because your eyes have to learn to
diverge
slightly, quite literally causing eye muscle strain. I am sure I read at
the time a
suggestion that permanent damage could result, perhaps to children's
developing
eyes, intuitively I would suspect this is a real issue.

--
Graham.

%Profound_observation%

Don't worry. The separation of the two complementary coloured images
(red-cyan or whatever) has to be adjusted at source to ensure that the
viewer's eyes are focused and converged at a comfortable distance. This is
usually arranged so that the image of the nearest object in the scene is at
or just behind the apparent window defined by the TV screen-surround. The
image displacement is not quite like a static convergence error, the
separation being a function of distance (depth) within the image. Also,
since the
coloured specs have no optical power, there is no danger of mis-convergence
from the specs themselves.

TrevM

3D test on Channel 4
 

"Stephen" wrote in message
...
These systems are all rubbish. Only Sky TV are doing it properly. Their
system uses glasses that are the same colour for each eye, don't need a
shutter or the associated heavy electronics in the frames of the glasses,
and shouldn't give anyone a headache. And they're getting Gucci to make
the frames so they're as much of a desirable fashion accessory as the
headphones for an iPod.

http://www.which.co.uk/reviews-ns/sky-3dtv/index.jsp

"TV manufacturers including JVC, LG and Sony are working on 3DTV sets,
some of which are due to arrive on the market in 2010. Sky said that you
can watch Sky 3D TV on a 26-inch screen, but the larger the screen, the
better the results. Does 3D TV cause headaches?
Sky blamed historical flaws in 3D TV on traditional 2D filming methods.
Depth, movement, panning and zoom all need to be considered in a new way
when shooting 3D, Sky explained, and individual shots need to last longer
than the fast-paced sequences we are used to with regular TV. When it's
done right, Sky said, you can watch hours of 3D TV without getting a
headache. We did not experience any ill effects from our time viewing Sky
3D TV".

"By pressing the 3D TV button on the remote control, the TV changes the
way the clips are displayed. In simple terms, the left camera's footage is
played on the odd lines that make up a TV picture and the right camera's
footage is played on the even lines. The two images are then polarised by
the 3D TV’s special panel so that after being filtered by the 3D glasses,
your left eye sees only the left camera's footage and your right eye sees
only the right camera's footage. As two images occupy the screen,
resolution is halved, so a 1920 x 1080 HDTV would show 3D TV in 960 x 540
resolution."

"Sky 3D TV verdict: We were all impressed by the clips that we saw, and if
Sky's 3D TV package follows in the footsteps of its high-definition
packages, it could see significant success."

I wonder how they solved the ghosting problem that you get with these
polarised screens. This idea has been around for as long as polarised
sun-glasses, but the problem is that a polarised lens is not 100% effective
at filtering out light of other polarisations.

This can be seen if you pick up two pairs of polarised sunglasses, or two
pairs of 3D glasses. In the case of sunglasses, place either lens of one
pair of glasses over either lens of the other pair. Then, rotate one pair of
glasses so that it's perpendicular to the other. You will see that the lens
appears to go black - this is because, in theory, you've filtered out all
but horizontally polarised light at one lens, and all but vertically
polarised light in the other - and hence 0 light. But... look through it
carefully, especially at a light. You'll see you can still see through it.
It's not perfect. Similarly, with 3D glasses, if you place the left lens of
one pair of glasses over the right lens of the other, it should go
completely black, but again, it's not... almost... but not 100% black.

And it's this that's the problem. You see a minor ghost effect all the time
when watching 3DTV of this type using polarised glasses. Whatever anybody
says, this causes headaches. Maybe they've improved lately, but this was
certainly a problem as recent as a year ago. Are they really that good?

Anyway... this type of 3D TV still doesn't address the problem that the TV
and the viewer has to be perfectly aligned in terms of the horizontal. The
glasses must be perfectly aligned to the TV. The more you rotate your head
relative to the TV the worse the ghosting effect is. At 45 degrees you will
see both left and right eye images through both your left and right eyes
equally. At a 90 degree tilt (such as when lying down on your side to watch
TV) you will see the wrong image in each eye, and the 3D effect will be
inverted.

I would imagine most people, at home, do not view the TV sat straight up in
their seat. Most people slouch on their couch, or lie down, or lean on the
arm rest. Anyone in this boat will see ghosting. The more they lean over the
worse it will be. The worst the ghosting the worse the headaches and
blurriness of the image.

--
Vincent