3D broadcsasts
 

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

3D broadcsasts
 

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.

3D broadcsasts
 

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

--
--
From the sofa of Brian Gaff -

Blind user, so no pictures please!
"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

3D broadcsasts
 

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.

--
Pete
Lose (rhymes with fuse) is a verb, the opposite of find. Loose (rhymes
with juice) is an adjective, the opposite of tight.

3D broadcsasts
 

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.


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.

Curiously enough, I watched and recorded some of the 3D highlights when
they were repeated this morning, and thought that the canoe slalom
material was particularly effective. I think I can see what you
mean about the poles. Certainly the canoeists didn't always pass the
poles on the side that I was expecting.

Obviously much depends on the nature of the material and the way it has
been handled. I think the 3D title sequences are just brilliant :-)

3D broadcsasts
 

Yes, I can imagine walking about with a camera with lenses that slide apart
as you zoom.
I do remember binoculars back in the 80s doing this. Sitting on a cliff top
in Guernsey looking at the comings and goings at St Peter Port harbour, all
the ferries looked like cardboard cutouts.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Pete Shew" wrote in message
o.uk...
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.

--
Pete
Lose (rhymes with fuse) is a verb, the opposite of find. Loose (rhymes
with juice) is an adjective, the opposite of tight.

3D broadcsasts
 

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 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
 

"mikeos" wrote in message
...
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.

Do both her eyes work?

3D broadcsasts
 

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

-- Richard

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

3D broadcsasts
 

Jim Lesurf wrote:

But maybe 3D is just another way to get people to buy (another)
'new TV set'. :-)

Personally, I love watching TV in 3D and think it greatly enhances the
viewing experience. It's something that tickles my visual taste buds.
But some people just don't seem to get it at all.

I see myself as being visually orientated, but others may have varying
degrees of stereo 3D perception, just as some people are partially or
completely colour blind. I suspect that many subscribers to this
newsgroup are of a certain age and have impaired vision in any case.
The instructions for my 3D TV actually state that "seniors" should
refrain from watching TV in 3D !!

Many have spent good money on 2D tellies and don't want to be told that
their equipment is now obsolete. Some people dislike having to wear
special glasses. There is also the fact that the usual viewing systems
have technical limitations, and I put off buying a 3D TV and devised my
own 3D viewing system using two monitors. But when Sainsburys brought
out a 42" 3D TV at basement bargain price, the temptation to buy one was
irresistible.

Bill Turnbull on Breakfast TV this morning said he was dubious about 3D
TV, but watched the Olympic highlights last night and thought the 3D was
amazing. He failed to mention that the show is repeated on BBC HD at
least from 7:00 to 9:00 am the following morning.

--
John L

3D broadcsasts
 

In article ,
John Legon wrote:

I suspect that many subscribers to this
newsgroup are of a certain age and have impaired vision in any case.

Of course some people may have poor vision. But others have excellent
vision and just don't think 3D television and film are very good.
They don't complain that they can't see the 3D effect: they complain
that it's unrealistic. In fact, it is likely to be the people with
better stereo vision who can see how poor it is.

-- Richard

3D broadcsasts
 

"John Legon" wrote in message
o.uk...
Jim Lesurf wrote:

But maybe 3D is just another way to get people to buy (another)
'new TV set'. :-)

Personally, I love watching TV in 3D and think it greatly enhances the
viewing experience. It's something that tickles my visual taste buds. But
some people just don't seem to get it at all.

I see myself as being visually orientated, but others may have varying
degrees of stereo 3D perception, just as some people are partially or
completely colour blind. I suspect that many subscribers to this
newsgroup are of a certain age and have impaired vision in any case. The
instructions for my 3D TV actually state that "seniors" should refrain
from watching TV in 3D !!

Many have spent good money on 2D tellies and don't want to be told that
their equipment is now obsolete. Some people dislike having to wear
special glasses. There is also the fact that the usual viewing systems
have technical limitations, and I put off buying a 3D TV and devised my
own 3D viewing system using two monitors. But when Sainsburys brought out
a 42" 3D TV at basement bargain price, the temptation to buy one was
irresistible.

Bill Turnbull on Breakfast TV this morning said he was dubious about 3D
TV, but watched the Olympic highlights last night and thought the 3D was
amazing. He failed to mention that the show is repeated on BBC HD at
least from 7:00 to 9:00 am the following morning.

I think it's more a matter of the constant desire to 'chase reality' and
make what isn't real appear real, for a time, until our clever brains catch
up.

Paintings to photographs.

Still photographs to moving pictures. (Remember the story of people
recoiling from a cine film of a train approaching them along a platform.)

Monochrome to colour.

Now 2D to 3D.

In the future binocular 3D to holograms.

Some time ago I was watching TV - in front of a window - and my eye wandered
to a cat outside walking about. When I looked back to the screen, for a
moment, the picture looked much more 'real' somehow, and then it reverted.

Our brains will always twig that the image isn't real eventually.

--
Max Demian

3D broadcasts
 

On 30/07/2012 18:08, Brian Gaff wrote:
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


On TV a little while ago they had a woman that could see in 3d who
previously could not and she described the cardboard cut out effect. it
is because it is new to the viewer.

cannot remember the programme I think it was on BBC

3D broadcsasts
 

"Martin" wrote in message
...
On Tue, 31 Jul 2012 08:26:34 +0100, John Legon
wrote:

Jim Lesurf wrote:

But maybe 3D is just another way to get people to buy (another)
'new TV set'. :-)

Personally, I love watching TV in 3D and think it greatly enhances the
viewing experience. It's something that tickles my visual taste buds.
But some people just don't seem to get it at all.

I see myself as being visually orientated, but others may have varying
degrees of stereo 3D perception, just as some people are partially or
completely colour blind. I suspect that many subscribers to this
newsgroup are of a certain age and have impaired vision in any case.
The instructions for my 3D TV actually state that "seniors" should
refrain from watching TV in 3D !!

Many have spent good money on 2D tellies and don't want to be told that
their equipment is now obsolete.

Especially when it isn't.

Some people dislike having to wear
special glasses. There is also the fact that the usual viewing systems
have technical limitations, and I put off buying a 3D TV and devised my
own 3D viewing system using two monitors. But when Sainsburys brought
out a 42" 3D TV at basement bargain price, the temptation to buy one was
irresistible.

Bill Turnbull on Breakfast TV this morning said he was dubious about 3D
TV, but watched the Olympic highlights last night and thought the 3D was
amazing. He failed to mention that the show is repeated on BBC HD at
least from 7:00 to 9:00 am the following morning.

How many events are being shown in 3D?

The opening and closing ceremonies, plus the 100 metres final live on BBC
HD. And a 60 minute "roundup" late evening, repeated early morning on BBC
HD, compiled by Olympic Broadcasting Services.
Eurosport HD is showing lots of coverage in 3D - see
http://uk.eurosport.yahoo.com/news/e...091240127.html

--
JohnT

3D broadcsasts
 

Richard Tobin wrote:
In article ,
John Legon wrote:

I suspect that many subscribers to this
newsgroup are of a certain age and have impaired vision in any case.

Of course some people may have poor vision. But others have excellent
vision and just don't think 3D television and film are very good.
They don't complain that they can't see the 3D effect: they complain
that it's unrealistic. In fact, it is likely to be the people with
better stereo vision who can see how poor it is.

I'm inclined to agree that stereoscopic 3D as seen on a conventional 3D
TV is unrealistic, but despite the limitations of the format I still
find the effect impressive and enjoyable. I get more compelling and
"immersive" results with my 3D viewing system, which separates the left
and right image paths and gives some control over eye-ball convergence
and focusing.

3D broadcsasts
 

On 31/07/2012 15:46, John Legon wrote:
Richard Tobin wrote:
In article ,
John Legon wrote:

I suspect that many subscribers to this newsgroup are of a certain
age and have impaired vision in any case.

Of course some people may have poor vision. But others have excellent
vision and just don't think 3D television and film are very good.
They don't complain that they can't see the 3D effect: they complain
that it's unrealistic. In fact, it is likely to be the people with
better stereo vision who can see how poor it is.

I'm inclined to agree that stereoscopic 3D as seen on a conventional 3D
TV is unrealistic, but despite the limitations of the format I still
find the effect impressive and enjoyable. I get more compelling and
"immersive" results with my 3D viewing system, which separates the left
and right image paths and gives some control over eye-ball convergence
and focusing.

on my Samsung you can adjust the 3d separation.

3D broadcsasts
 

Gary wrote:

on my Samsung you can adjust the 3d separation.

That's good. Given that my Sainsburys 42" Celcus 3DTV currently sells
for just &320 with four pairs of glasses it would be unreasonable to
expect all the bells and whistles, though it does have 4 HDMI, 2 SCART,
2 USB, component and composite video and VGA, and a media player that
will play my satellite box SD recordings "as is". HD recordings have to
be converted to MPEG2 or Xvid before they will play. The LG panel is
slightly lacking in the depth of the blacks when compared side by side
with my Samsung screen, especially off-axis, but it is also brighter.

3D broadcsasts
 

In article , Pete
Shew writes
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.

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.

It would seem like that, but there is a lot more to it.

I have one of those Fuji-W3 3D cameras which, admittedly, I bought as a
gimmick after a colleague showed me some images from one last year. The
W3 has a 3x optical zoom but the lens separation is fixed at 75mm and
there is surprisingly little difference in effective depth going from
min to maximum zoom. In fact, at maximum telephoto it often appears
that the depth perception is greater. Applying further digital zoom to
an effective 17x increases the depth resolution even more, despite the
loss in spatial resolution at high digital zoom ratios.

Also, although the absolute depth resolution reduces at distance reduces
this is less obvious than it might seem because spatial resolution
reduces by the same amount - so it just "looks right".

I was really surprised with some shots I took looking across the Grand
Canyon earlier this year. Although the other side is on average 10
miles away, the 3D effect was really impressive. Of course the sides of
the far canyon walls range from 8 to 15 miles so there is a lot of depth
variation, but I was surprised how well it worked with only a 75mm
baseline. I was really glad I had taken it along as I only intended to
use it for relatively close images.

The W3 has a mode which allows for separate shots for the left and right
images, permitting much larger baseline separation to be achieved if
desired. However, when I have tried to use this I find the results much
less convincing than the default separation. I suspect this has to do
with getting the convergence right, which the W3 seems to continually
adjust depending on focus distance, although the L-R separation does
need some adjustment at extremely close distances in the macro region.

The great thing about the Fuji camera is that the display is a
lenticular LCD screen, so it shows 3D without any glasses at all. One
day, all 3D displays will be like that! ;-)
--
Kennedy

3D broadcsasts
 

R. Kennedy McEwen wrote:
In article , Pete
Shew writes
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.

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.

It would seem like that, but there is a lot more to it.

I have one of those Fuji-W3 3D cameras which, admittedly, I bought as a
gimmick after a colleague showed me some images from one last year. The
W3 has a 3x optical zoom but the lens separation is fixed at 75mm and
there is surprisingly little difference in effective depth going from
min to maximum zoom. In fact, at maximum telephoto it often appears
that the depth perception is greater. Applying further digital zoom to
an effective 17x increases the depth resolution even more, despite the
loss in spatial resolution at high digital zoom ratios.

Also, although the absolute depth resolution reduces at distance reduces
this is less obvious than it might seem because spatial resolution
reduces by the same amount - so it just "looks right".

I was really surprised with some shots I took looking across the Grand
Canyon earlier this year. Although the other side is on average 10
miles away, the 3D effect was really impressive. Of course the sides of
the far canyon walls range from 8 to 15 miles so there is a lot of depth
variation, but I was surprised how well it worked with only a 75mm
baseline. I was really glad I had taken it along as I only intended to
use it for relatively close images.

The difference in parallax from a 75 mm baseline to objects 10 and 15
miles away must be negligible, surely? Having said that, I've been
surprised by the 3D effect in scenic views and aerial photography.
Recent examples have been the aerial shots of London in the Olympic 3D
coverage. I've tended to assume that the baseline was somewhat larger
than the human eyeball spacing.

Here's an example taken from the Jedi 3D channel at 30 degrees west,
which I have converted from side-by-side to anaglyph 3D to illustrate
the variations in parallax. The colour fringing shows the amount of
parallax, which in this instance has evidently been adjusted to be zero
for the buildings in the middle distance, in front of the church. Hence
when viewed with red/cyan glasses, the foreground might be interpreted
as being in front of the TV screen.

http://www.john-legon.co.uk/temp/jediscene1.jpg

Perhaps someone with a working brain can estimate what the baseline is
roughly likely to be in this image?

--
John L

3D broadcsasts
 

In article , John
Legon writes
R. Kennedy McEwen wrote:
I was really surprised with some shots I took looking across the
Grand Canyon earlier this year. Although the other side is on
average 10 miles away, the 3D effect was really impressive. Of
course the sides of the far canyon walls range from 8 to 15 miles so
there is a lot of depth variation, but I was surprised how well it
worked with only a 75mm baseline. I was really glad I had taken it
along as I only intended to use it for relatively close images.

The difference in parallax from a 75 mm baseline to objects 10 and 15
miles away must be negligible, surely?

You would think so but, as I said, I was surprised that it works.
--
Kennedy

3D broadcsasts
 

On 03/08/2012 08:15, R. Kennedy McEwen wrote:
In article , John
Legon writes
R. Kennedy McEwen wrote:
I was really surprised with some shots I took looking across the
Grand Canyon earlier this year. Although the other side is on
average 10 miles away, the 3D effect was really impressive. Of
course the sides of the far canyon walls range from 8 to 15 miles
so there is a lot of depth variation, but I was surprised how well
it worked with only a 75mm baseline. I was really glad I had taken
it along as I only intended to use it for relatively close images.

The difference in parallax from a 75 mm baseline to objects 10 and 15
miles away must be negligible, surely?

You would think so but, as I said, I was surprised that it works.

the fuji camera has an auto adjustment to get the separation to look the
best. It is also manually adjustable.

3D broadcsasts
 

In article ,
John Legon wrote:

The difference in parallax from a 75 mm baseline to objects 10 and 15
miles away must be negligible, surely?

Well, let's see. If the baseline is b and the distance to the object
is d with b d, an object directly ahead of one "eye" will be at an
angle b/d (radians) off the axis for the other "eye". For two such
objects at d1 and d2, the difference in angle will be b/d1 - b/d2. If
the angle of view of the camera is v, this will be a proportion
(b/d1 - b/d2)/v of that angle. If the horizontal pixel count of
the camera is p, the difference in disparity in pixels will be

pb/v (1/d1 - 1/d2)

So for b = 75mm, d1 = 8 miles ~= 13km, d2 = 15 miles ~= 23km, v = 0.3
radians, and p = 4,000 we would get a disparity difference of 0.03
pixels.

I suppose it's just about possible that one can resolve and interpret
such a difference, given that features will be present in many
consecutive scan lines, but it's rather surprising.

Could you (the photographer) measure the difference or post the photo
so someone else can?

-- Richard

3D broadcsasts
 

John Legon schrieb:
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.


Well, it depends - the adjustable 3D rigs are using two normal cameras
behind a half mirror box which is bending one view 90 degrees down (for
the right side view). For distant objects the separation of the two
cameras must get higher than normal eye-parallaxe for decent 3D effects.

The professional Panasonic 3D video camera 3DA1 has two lenses
side-by-side 60 mm apart, and this seems to be used at most olympic
venues shown at night. So the wide area shots are less impressive than
the ones close by the camera, and not all camera operators are
experienced 3D "stereographs"...

3D broadcsasts
 

Klaus wrote:
John Legon schrieb:
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.


Well, it depends - the adjustable 3D rigs are using two normal cameras
behind a half mirror box which is bending one view 90 degrees down (for
the right side view). For distant objects the separation of the two
cameras must get higher than normal eye-parallaxe for decent 3D effects.

The type of 3D rig you describe with horizontal and vertical cameras was
shown in a Sky 3D demo (I think) some time ago on Astra 19.2 E.

Do you know roughly what the camera separation might be for the scene I
posted the other day ? I converted this from side-by-side to anaglyph,
so the colour fringes indicate the parallax:

http://www.john-legon.co.uk/temp/jediscene1.jpg

It seems to me that the "baseline" must be something like 50 cm to give
the variation in parallax (negative to positive) from the foreground to
the background, but I don't know whether this is probable or possible.


The professional Panasonic 3D video camera 3DA1 has two lenses
side-by-side 60 mm apart, and this seems to be used at most olympic
venues shown at night. So the wide area shots are less impressive than
the ones close by the camera, and not all camera operators are
experienced 3D "stereographs"...


Thanks for the interesting info...

3D broadcsasts
 

In article , Gary
writes
On 03/08/2012 08:15, R. Kennedy McEwen wrote:
In article , John
Legon writes
R. Kennedy McEwen wrote:
I was really surprised with some shots I took looking across the
Grand Canyon earlier this year. Although the other side is on
average 10 miles away, the 3D effect was really impressive. Of
course the sides of the far canyon walls range from 8 to 15 miles
so there is a lot of depth variation, but I was surprised how well
it worked with only a 75mm baseline. I was really glad I had taken
it along as I only intended to use it for relatively close images.

The difference in parallax from a 75 mm baseline to objects 10 and
15 miles away must be negligible, surely?

You would think so but, as I said, I was surprised that it works.

the fuji camera has an auto adjustment to get the separation to look
the best. It is also manually adjustable.

That is the *DISPLAY* separation, which adjusts for comfortable viewer
eye convergence. It has a fixed *OPTICAL* separation of 75mm.

It is the optical separation which creates the 3D effect and which is
the subject of the discussion.
--
Kennedy