3D Television

[timtadams]

So we have these 3D ready TVs coming out here in Australia next week i think, if not already, i think

So im like, why the hell do we need special TVs to view 3D? There is nothing special about watching it at the movies, is there?

According to wikipedia:
"3D-ready TV sets are those that can operate in 3D mode (in addition to regular 2D mode), in conjunction with LCD shutter glasses, where the TV tells the glasses which eye should see the image being exhibited at the moment, creating a stereoscopic image. These TV sets usually support HDMI 1.4 and a minimum (input and output) refresh rate of 120Hz; glasses may be sold separately."

I am also aware that 3D movies such as Avatar and Clash of the Titans will no doubt come out on 3D, as well as other movies. Also, Avatar the game has the option to be played in 2d or 3D according to an article i read months ago.

Now at the movies they just give everyone polarised glasses and a bit of a fuzzy image and magically it looks 3D, or am i missing something?

Now im wondering if it will still be possible to watch 3D on a normal Full HighDef TV just using polarised glasses...we used to be able to do it with the red and green plastic (although it was fairly shoddy).

I just dont understand why they need special TVs. Are there any tech savvy people here who know? And would i still be able to play Avatar in 3D on a full High Def TV? (hypothetically - im probably not getting the game )

And any other comments are appreciated, like how long has this been out in your country?

 

[Dimitar]

I don't see why they would need special TVs, it's all about the film, not the TV imo.

3D is achieved quite easily it seems, just put 3 layers of picture on top of each other, put on the glasses and you get 3D ;o

 

[Azzer]

The 120hz refresh rate I believe is the key - the ability to send enough images to the screen so that each eye is getting an entirely different set of images, but overall each eye is receiving the same total number of images that a "normal" telly could display in the same time-frame.

Older televisions do not support such a high refresh rate at high definition.

 

[Weeble]

What big nose said. Most LCD TVs are roughly 60Hz (refresh 60 times a second) with a maximum of around 80 which is enough to not cause headaches (as the human eye sees at roughly 25fps). In order to keep the same quality, a 3D TV would have to supply *both* eyes with the same number of frames in the same time period. If you did it with current TVs (using stereoscopic shutter glasses) then each eye would only see at 30Hz which would give you monumental headaches, hence the 120Hz TVs which means each eye sees a 60Hz TV.

 

[Cheese]

Do you still need the 3d glasses for these 3d tvs?

 

[Weeble]

You do need glasses but not the traditional red/blue lighting gel versions. They're a bit more sophisticated and less obvious to your eyes

 

[Cheese]

Hmm what happens if you have 7 friends round and 5 pairs of glasses
Epic fail for 3d TV!

 

[Weeble]

There are actually 3D projection/holographic screens available which don't require glasses but they're quite large and cumbersome. The effect is pretty good though!

I'm curious to see how good Sharp's new 3D screen they're starting to mass produce for mobile phones etc is. It has slits in it that angle different images to each of your eyes producing the 3D effect - unfortunately this severely hampers the viewing angle meaning it's only really feasible for small devices intended for one user. That's why you don't get the same tech in TVs ;-)

 

[timtadams]

What big nose said. Most LCD TVs are roughly 60Hz (refresh 60 times a second) with a maximum of around 80 which is enough to not cause headaches (as the human eye sees at roughly 25fps). In order to keep the same quality, a 3D TV would have to supply *both* eyes with the same number of frames in the same time period. If you did it with current TVs (using stereoscopic shutter glasses) then each eye would only see at 30Hz which would give you monumental headaches, hence the 120Hz TVs which means each eye sees a 60Hz TV.

but thats not how it works at the movies right? so theoretically, if i had the image they played at the movies, with my polarised glasses i got from the movies, then i would see 3D, but no problem with headaches, yes?

 

[Azzer]

but thats not how it works at the movies right? so theoretically, if i had the image they played at the movies, with my polarised glasses i got from the movies, then i would see 3D, but no problem with headaches, yes?

That's how it works at the cinema too, actually. Their projectors can send pictures at a very fast rate, fast enough so that there are enough images for each eye at a rate that neither eye can notice any "flicker". You'll find that any cinemas with older projectors either couldn't display the 3d version of films at all, or only in particular screens (usually their "biggest" screens, as they tend to have the more powerful projectors, but just depends what their projectors in each screen were capable of). It's entirely down to how quickly the device can display images.

Whether it's on a projector screen at the cinema or on a television in your home, you still need a device that can display enough images in a short enough time-frame... the device would be constantly displaying an image 1st for your left eye, then your right eye, then left eye, then right eye, over and over - at slightly different polarisations. The 3D glasses filter out the polarisation they're not meant to see - so your left eye only sees the set of images intended for the left eye, and likewise for the right. So each eye is only seeing every 2nd frame to the other eye, as intended - allowing the 3D effect to be produced, and produced very effectively (polarisation allows for more accurate pictures for 3D films than the old fashioned colour-based 3D associated with the 80's ).

 

[timtadams]

I see now, thanks Azzer

^did you see what i did there?

i was just confused as to why 3D TVs need special glasses. But i think i understand now.

And coincidentally i am researching about ellipsometry which relies on elliptically polarised light (gosh that was a hard concept to grasp 0_o)

 

[Weeble]

but thats not how it works at the movies right? so theoretically, if i had the image they played at the movies, with my polarised glasses i got from the movies, then i would see 3D, but no problem with headaches, yes?

That's how it works at the cinema too, actually. Their projectors can send pictures at a very fast rate, fast enough so that there are enough images for each eye at a rate that neither eye can notice any "flicker". You'll find that any cinemas with older projectors either couldn't display the 3d version of films at all, or only in particular screens (usually their "biggest" screens, as they tend to have the more powerful projectors, but just depends what their projectors in each screen were capable of). It's entirely down to how quickly the device can display images.

Whether it's on a projector screen at the cinema or on a television in your home, you still need a device that can display enough images in a short enough time-frame... the device would be constantly displaying an image 1st for your left eye, then your right eye, then left eye, then right eye, over and over - at slightly different polarisations. The 3D glasses filter out the polarisation they're not meant to see - so your left eye only sees the set of images intended for the left eye, and likewise for the right. So each eye is only seeing every 2nd frame to the other eye, as intended - allowing the 3D effect to be produced, and produced very effectively (polarisation allows for more accurate pictures for 3D films than the old fashioned colour-based 3D associated with the 80's ).

Not *strictly* true...

There are three main ways of watching 3D features;
One is to use three separate films - one "normal", one red shaded and offset, one green shaded and offset. You watch this using gel glasses set to the same colour (ish) meaning if you had glasses with left eye red, right eye green, the right eye wouldn't see the red image and the left eye wouldn't see the green image, which creates the 3D effect.

The second version is to use shuttered glasses which are pretty much normal glasses, except they have the ability to completely blank out one eye at a time. These glasses are synchronised with the projector (or TV) so that when the projector/TV is displaying a "left-eye" image, the right eye is blanked out and vice versa. This is common for home systems.

The third and most popular in cinemas is the polarised effect. Two films are played pretty much at the same time on a special screen (no need to display one frame of one then the next frame of the other); one with vertical polarisation, the other with horizontal polarisation. The glasses only then need to have different polarised lenses for each eye (one horizontal, one vertical) so that the other eye doesn't see what it's not supposed to. You can sort of see it in effect if you tilt your head while watching a 3D screening at the cinema.

 

[timtadams]

Awesome explanation weeble, now i completely understand

 

[Davis]

I read a first few of the posts, and idk if this has been answered, but about the 3D Movie Theater and how its different. Beyond the refresh rate they newer (RealD) 3D systems require it to be played on something called a "Silver Screen" i cant remember the full reasoning behind this but thats a reason why you cant just watch new (not red/blue glasses) 3D at home.

 

[timtadams]

Was just thinking, how the avatar game can be played in 3d, couldnt all games be played in 3D? Everything is already there for 3D viewing, you just need two points of reference to give two slightly different images for each of your eyes.

I was thinking that this might be possible with a firmware update for consoles, but figured you would actually need a software patch for the game itself? Thoughts anyone?

 

[Weeble]

You'd also need to ensure a TV that has a refresh rate of at least 120 Hz. Most current TVs are between 50 and 70Hz. In order to create a good 3D version of a game you'd need to go through one of the processes described above.

It's possible to "fake" 3Dness on existing products by repeating the same image three times on one screen, colouring two of them, but beyond that it's hard to create true 3D. You'd have to go back and implement a secondary viewpoint in the game that's roughly equal to the width of your eyes (so each camera represents one eye) and then patch that into every game. Something most developers wouldn't care to do!

And Davis - yeah that was answered ;-)

 

[timtadams]

You'd also need to ensure a TV that has a refresh rate of at least 120 Hz. Most current TVs are between 50 and 70Hz. In order to create a good 3D version of a game you'd need to go through one of the processes described above.

yeah i know that part

You'd have to go back and implement a secondary viewpoint in the game that's roughly equal to the width of your eyes (so each camera represents one eye) and then patch that into every game. Something most developers wouldn't care to do!

Would it really be that hard to create a second viewpoint? I mean games in 3D environments arent exactly in their infancy, theyve been basically doing the same thing for the last 20 years (or w/e), just better

I dont plan on getting a new TV, since i got a new one 6 months ago, but i think the concept of playing FPS' in 3D would be cool...hmm MW2 in 3D....

 

[Weeble]

Yeah a fair amount of extra work is required to turn a pre-existing 2D game into a 3D one. It just wouldn't be cost-efficient really.

 

[timtadams]

Yeah a fair amount of extra work is required to turn a pre-existing 2D game into a 3D one. It just wouldn't be cost-efficient really.

Youre not making a 2d game 3d. Your taking a 3d game thats presented in 2d via a single viewpoint, and adding another viewpoint. Now you have two images to give you 3d. You dont change the game, just add a viewpoint, how hard can that be?

So i decided to do a bit of browsing:
http://www.nvidia.com/object/3D_Vision_3D_Games.html

also:

So how does the Nvidia driver actually make the two images that form the stereo 3D image? All 3D games and applications use what is called a camera to produce the image seen on screen. The camera represents a position in the game or application space and an angle from which to produce the said image. The Nvidia driver adjusts this camera so that it produces two images at two distinct angles based on the location and angle of this camera. One of these two pictures gets synchronized to the left eye & the other picture gets synchronized to the right eye. Thus producing the two animated images which together produce a visual depth.

Nvidia 3D Vision - Playing Direct 3D Games in "Stereo 3D, The Magic of the 3D Stereo Technology:", paragraph 6 <http://www.experts-exchange.com/articles/Digital_Living/Gaming_World/Nvidia-3D-Vision-Playing-Direct-3D-Games-in-Stereo-3D.html>

So as i was originally thinking, consoles could simply have a firmware update to allow games to be played in 3D

[edit]
According to Sony at tonight's conference, every single PS3 can be upgraded via a firmware update to support 3D content, either games, video downloads, or 3D Blu-ray.
http://au.ps3.ign.com/articles/105/1058899p1.html

 

[Weeble]

Point taken, but the fact remains you're still going to have to go back to the old game, add a secondary viewpoint, re-play the entire game to check for any discrepancies, probably re-do most cutscenes and then re-release, all for not very much return. I doubt everyone that bought the original of a game would buy the 3D version "just because". Sure it'd be possible, just fairly pointless