3D broadcsasts
 

Davey wrote:

Ah, memories of Viewmaster! I still remember seeing The Canadian
Rockies for the first time through one of them.

Snap ! I still have a disc of the Frazer Canyon and a Bakelite viewer.

3D broadcsasts
 

"Richard Tobin" wrote in message
...
I watched the 3D Olympic highlights on BBC HD this evening. I was not
surprised to be unimpressed.

As with the 3D cinema films I've seen, the objects appeared at
different depths, but had no noticable depth themselves, giving the
impression that the people were cardboard cutouts moved in front of
flat backgrounds. I'm not sure what causes this - perhaps there is
effectively very low resolution in the depth.

More bizarre was the kayak slalom, where the poles seemed to be at
peculiar depths. Often when a kayaker (if that's the word) approached
a pole he would appear to be on one side of it, but when he passed it
it would become apparent that he was on the other side. The effect
was somewhat Escher-esque.

A friend who watched it with me noticed the same effects, so it's
not just my eyes.

-- Richard

When you look at the real world you see it without magnification, and for
close up object the 3D effect is quite noticeable (just try closing one eye
and then swap while looking at your living room).

The difference in parallax is much less at a distance and as most TV sport
coverage is shown through telephoto zoom lenses that are quite close
together, you lose a lot of depth perception.

During the war range finding binoculars used by the observer core used tubes
and prisms to separate the objective lenses by ~2m. Here is an earlier one
http://www.museumoftechnology.org.uk/expand.php?key=740

3D broadcsasts
 

On 30/07/2012 08:17, mikeos wrote:
On 30/07/2012 04:13, Richard Tobin wrote:
I watched the 3D Olympic highlights on BBC HD this evening. I was not
surprised to be unimpressed.

As with the 3D cinema films I've seen, the objects appeared at
different depths, but had no noticable depth themselves, giving the
impression that the people were cardboard cutouts moved in front of
flat backgrounds. I'm not sure what causes this - perhaps there is
effectively very low resolution in the depth.

More bizarre was the kayak slalom, where the poles seemed to be at
peculiar depths. Often when a kayaker (if that's the word) approached
a pole he would appear to be on one side of it, but when he passed it
it would become apparent that he was on the other side. The effect
was somewhat Escher-esque.

A friend who watched it with me noticed the same effects, so it's
not just my eyes.

-- Richard

Some people cannot see the stereo effect at all. My wife is one of them.

As I'm nearly blind in one eye, same here. Funnily enough, although I
can't see the 3D effects on Panasonic or Sony TVs with active glasses,
on LG TVs with the passive glasses I can. Weird. In any event, when I
have watched 3D TV all I end-up with is a headache and a deep sense of
'so what?'. It was a gimmick when it was first trialled umpteen years
ago, and, IMHO, it's a gimmick now, spun-up by kit manufacturers to try
and garner sales.


Clem

3D broadcsasts
 

Jim Lesurf wrote:
How far apart are the lenses on the 3D cameras? Presumably that would let
us know the distances at which a point shifts sideways by one pixel in the
two pixel-arrays.

With the 3D cameras as used in broadcasting the spacing can be varied.
Although it can be the same as for human eyes - about 65 mm - the amount
of parallax I see in some 3D material suggests to me that it is
sometimes much greater.

3D broadcsasts
 

In article ,
Richard Tobin wrote:
In article ,
Jim Lesurf wrote:

How far apart are the lenses on the 3D cameras? Presumably that would let
us know the distances at which a point shifts sideways by one pixel in the
two pixel-arrays.

As font antialising shows, we can interpret intermediate levels to
resolve an edge to better than pixel resolution, so it shouldn't be
quite that bad.

Indeed. However IIRC earlier discussions wrt artifacts on transmitted
images showed that broadcasters may simply fail to ensure the images are
spatially sampled in accord with sampling theory. Hence, I suspect, the
reason for the 3D artifacts reported in this thread!


But of course we are looking at a lossily-compressed image.

In itself, I'd expect that to blur images. But you may be right that it
also decides to 'group' sets of pixels for the purpose of reducing the bits
needed for movement, thus generating the 'cardboard cutout' effect. If so,
it presumably isn't dealing with the 3D aspect very well.

Curious if the designers of the 3D systems haven't realised that and dealt
with it. But maybe 3D is just another way to get people to buy (another)
'new TV set'. :-)

I'd still be interested in the answer to my question, though.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

3D broadcsasts
 

That is right Viewmaster, sent one to a charity shop recently.

Can no longer use them of course. I can remember the cardboard cutout
though. Well before holograms or anything like that. Does anyone remember th
famous hologram of the tap that appeared to stick out with kind of frozen
water coming from it?
That was weird.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Davey" wrote in message
...
On Mon, 30 Jul 2012 10:52:56 +0100
Pete Shew wrote:

On 30/07/2012 09:05, Brian Gaff wrote:
Well when I could see I had one of those 3D binocular photo
viewers, and those had the cardboard cut out effect as well. My
feeling on a lot of it is that the spacing of the lenses and the
amount of telephoto used on a given picture has a great effect on
the appearence of depth information. Unfortunately when looking at
where cameras have to be in sports events etc, its probably an
unavoidable side effect unless some kind of digital enhancement can
be used to make it look more natural.

Brian

It's the same with binoculars, especially the compact ones with
objectives closer than the eyepieces. How far apart are the camera
lenses? It would seem that the telephoto shots would need more
separation so that the apparent angle at the effective distance is
about 10cm.


Ah, memories of Viewmaster! I still remember seeing The Canadian
Rockies for the first time through one of them.
--
Davey.
--
Davey.

3D broadcsasts
 

Yes the transparancy ones with the wheel were better than the photo slide in
ones, but you still got the cardboard effect. I could not afford one of
those...
Brian

--
From the Sofa of Brian Gaff Reply address is active
"John Legon" wrote in message
o.uk...
Davey wrote:

Ah, memories of Viewmaster! I still remember seeing The Canadian
Rockies for the first time through one of them.

Snap ! I still have a disc of the Frazer Canyon and a Bakelite viewer.

3D broadcsasts
 

Hmm, I assume that most of the cinema films recently which were re releases
of ordinary films were created digitally , and one cannot help wondering if
the cardboard effect is due to insufficient data for the round the corner
views so to speak. It makes you wonder if the tv system has some way to
enhance the effect which looks crappy. I miss my sight at times like this,
but still feel current 3D systems are just a short lived fad.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Jim Lesurf" wrote in message
...
In article , John
Legon
wrote:
Richard Tobin wrote:
I watched the 3D Olympic highlights on BBC HD this evening. I was not
surprised to be unimpressed.

As with the 3D cinema films I've seen, the objects appeared at
different depths, but had no noticable depth themselves, giving the
impression that the people were cardboard cutouts moved in front of
flat backgrounds. I'm not sure what causes this - perhaps there is
effectively very low resolution in the depth.

Sometimes referred to as the puppet theatre effect. I haven't been very
conscious of this myself with the Olympic 3D material, but think it can
happen with telephoto shots if the 3D perspective is exaggerated and the
resolution is insufficient.

How far apart are the lenses on the 3D cameras? Presumably that would let
us know the distances at which a point shifts sideways by one pixel in the
two pixel-arrays.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

3D broadcsasts
 

On Mon, 30 Jul 2012 17:59:09 +0100
"Brian Gaff" wrote:

That is right Viewmaster, sent one to a charity shop recently.

Can no longer use them of course. I can remember the cardboard cutout
though. Well before holograms or anything like that. Does anyone
remember th famous hologram of the tap that appeared to stick out
with kind of frozen water coming from it?
That was weird.

Brian


This fella was my live-in house warden at Luffy:
https://en.wikipedia.org/wiki/Nicholas_J._Phillips
He knew a thing or two about holograms, I watched one being made once,
back in 1969.
--
Davey.

3D broadcasts
 

I remember seeing those when I was at school in the 60s, and thought they
would be really cool, if a little awkward to take on holiday!

Brian

--
From the Sofa of Brian Gaff Reply address is active
"R. Mark Clayton" wrote in message
...

"Richard Tobin" wrote in message
...
I watched the 3D Olympic highlights on BBC HD this evening. I was not
surprised to be unimpressed.

As with the 3D cinema films I've seen, the objects appeared at
different depths, but had no noticable depth themselves, giving the
impression that the people were cardboard cutouts moved in front of
flat backgrounds. I'm not sure what causes this - perhaps there is
effectively very low resolution in the depth.

More bizarre was the kayak slalom, where the poles seemed to be at
peculiar depths. Often when a kayaker (if that's the word) approached
a pole he would appear to be on one side of it, but when he passed it
it would become apparent that he was on the other side. The effect
was somewhat Escher-esque.

A friend who watched it with me noticed the same effects, so it's
not just my eyes.

-- Richard

When you look at the real world you see it without magnification, and for
close up object the 3D effect is quite noticeable (just try closing one
eye and then swap while looking at your living room).

The difference in parallax is much less at a distance and as most TV sport
coverage is shown through telephoto zoom lenses that are quite close
together, you lose a lot of depth perception.

During the war range finding binoculars used by the observer core used
tubes and prisms to separate the objective lenses by ~2m. Here is an
earlier one http://www.museumoftechnology.org.uk/expand.php?key=740