in my company we have been using stereoscopic shutter glasses for years together with fast crt screens able to handle vertical refresh rates > 120Hz. Lately it is getting extremely hard to find such monitors, so we decided to try out one of the new LCDs supporting 120Hz refresh, and, as promised on the nVidia site, support 3D vision. We got a Samsung 2233RZ. The way we achive stereo is displaying alternating left and right images at 120Hz (using DirectX), with shutters alternating open/close for the corresponding eye (by sending trigger synced to DirectX), so the actual image is perceived in 3D at 60Hz. This system works, without doubt.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
in my company we have been using stereoscopic shutter glasses for years together with fast crt screens able to handle vertical refresh rates > 120Hz. Lately it is getting extremely hard to find such monitors, so we decided to try out one of the new LCDs supporting 120Hz refresh, and, as promised on the nVidia site, support 3D vision. We got a Samsung 2233RZ. The way we achive stereo is displaying alternating left and right images at 120Hz (using DirectX), with shutters alternating open/close for the corresponding eye (by sending trigger synced to DirectX), so the actual image is perceived in 3D at 60Hz. This system works, without doubt.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
in my company we have been using stereoscopic shutter glasses for years together with fast crt screens able to handle vertical refresh rates > 120Hz. Lately it is getting extremely hard to find such monitors, so we decided to try out one of the new LCDs supporting 120Hz refresh, and, as promised on the nVidia site, support 3D vision. We got a Samsung 2233RZ. The way we achive stereo is displaying alternating left and right images at 120Hz (using DirectX), with shutters alternating open/close for the corresponding eye (by sending trigger synced to DirectX), so the actual image is perceived in 3D at 60Hz. This system works, without doubt.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
in my company we have been using stereoscopic shutter glasses for years together with fast crt screens able to handle vertical refresh rates > 120Hz. Lately it is getting extremely hard to find such monitors, so we decided to try out one of the new LCDs supporting 120Hz refresh, and, as promised on the nVidia site, support 3D vision. We got a Samsung 2233RZ. The way we achive stereo is displaying alternating left and right images at 120Hz (using DirectX), with shutters alternating open/close for the corresponding eye (by sending trigger synced to DirectX), so the actual image is perceived in 3D at 60Hz. This system works, without doubt.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
[quote name='tritosine' post='1127054' date='Oct 6 2010, 11:53 AM']Not the case.[/quote]
[attachment=18439:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[quote name='tritosine' post='1127054' date='Oct 6 2010, 11:53 AM']Not the case.
[attachment=18439:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[quote name='tritosine' post='1127054' date='Oct 6 2010, 11:53 AM']Not the case.[/quote]
[attachment=23938:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[quote name='tritosine' post='1127054' date='Oct 6 2010, 11:53 AM']Not the case.
[attachment=23938:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?[/quote]
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?[/quote]
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
[quote name='tritosine' post='1127064' date='Oct 6 2010, 12:32 PM']What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.[/quote]
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
[quote name='tritosine' post='1127064' date='Oct 6 2010, 12:32 PM']What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
[quote name='tritosine' post='1127064' date='Oct 6 2010, 12:32 PM']What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.[/quote]
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
[quote name='tritosine' post='1127064' date='Oct 6 2010, 12:32 PM']What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode. Also, by the looks of it , the next crop of LED backlit LCD's wont help either, because they won't have any serious local dimming , just edge lit, light is wasted. /turned.gif' class='bbc_emoticon' alt=':turned:' />
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
[quote]- the screen does NOT write all pixels at the same time[/quote] ( indeed, top down)
[quote](is it even capable to?)[/quote]( no ) [quote]- the shutters are open for about 3mSec each 16mSec[/quote]( more like 1.5 - 2 )
[quote]- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?[/quote]
[url="http://www.youtube.com/watch?v=FAQh6bREFqM"]http://www.youtube.com/watch?v=FAQh6bREFqM[/url]
Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode. Also, by the looks of it , the next crop of LED backlit LCD's wont help either, because they won't have any serious local dimming , just edge lit, light is wasted. /turned.gif' class='bbc_emoticon' alt=':turned:' />
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
- the screen does NOT write all pixels at the same time
( indeed, top down)
(is it even capable to?)
( no )
- the shutters are open for about 3mSec each 16mSec
( more like 1.5 - 2 )
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode. Also, by the looks of it , the next crop of LED backlit LCD's wont help either, because they won't have any serious local dimming , just edge lit, light is wasted. /turned.gif' class='bbc_emoticon' alt=':turned:' />
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
[quote]- the screen does NOT write all pixels at the same time[/quote] ( indeed, top down)
[quote](is it even capable to?)[/quote]( no ) [quote]- the shutters are open for about 3mSec each 16mSec[/quote]( more like 1.5 - 2 )
[quote]- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?[/quote]
[url="http://www.youtube.com/watch?v=FAQh6bREFqM"]http://www.youtube.com/watch?v=FAQh6bREFqM[/url]
Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode. Also, by the looks of it , the next crop of LED backlit LCD's wont help either, because they won't have any serious local dimming , just edge lit, light is wasted. /turned.gif' class='bbc_emoticon' alt=':turned:' />
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
- the screen does NOT write all pixels at the same time
( indeed, top down)
(is it even capable to?)
( no )
- the shutters are open for about 3mSec each 16mSec
( more like 1.5 - 2 )
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
[quote name='tritosine' post='1127079' date='Oct 6 2010, 01:45 PM']Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode[/quote]
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
[quote]There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:[/quote]
I'd like to see what 'they' propose then.. imo technically impossible.
[quote name='tritosine' post='1127079' date='Oct 6 2010, 01:45 PM']Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
I'd like to see what 'they' propose then.. imo technically impossible.
[quote name='tritosine' post='1127079' date='Oct 6 2010, 01:45 PM']Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode[/quote]
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
[quote]There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:[/quote]
I'd like to see what 'they' propose then.. imo technically impossible.
[quote name='tritosine' post='1127079' date='Oct 6 2010, 01:45 PM']Yes, you got it "right". This is the real world scenario with LCD's right now. No hidden field sequential mode
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
I'd like to see what 'they' propose then.. imo technically impossible.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
No luck however, using the screen + our shutters as is didn't quite work:
- the pixels on an lcd are in their on state for the duration of a frame (8mSec)
- there is a delay of about half a frame before the frame sent out by the pc is actually drawn on the screen
- in other words, while a shutter is open (also 8mSec), the eye sees half of the left and half of the right image
We fixed this with some hardware that compensates for the delay and shortens the period the shutters are open. So far so good: 3D perception was really good, but only for small images in the middle of the screen.
Some more measurements revealed something very surprising for us: the 2233RZ does not show the entire frame in one go (what we expected from an LCD screen: any LCD we have here, also DLP projectors, all do that), but instead writes it line by line just as a crt would do.
So there is *no way* to get stereo working properly with shutters, because there is an 8mSec delay between the top left pixel being on and the bottom right pixel going one. Moreover, when the bottom right one is on, the top left one is already off.
The question is: how does nVidia do it, and can we do it to? The glasses from their 3D vision kit use the same principle as ours, so it must be in the screen/video card, no? How do they force the screen to show the entire frame in one go, so that all pixels go on and off at the same time? Is this something that can be set in software? Or can that only be done when using one of the GeForce cards listed as compatible for use with the 3D kit (we tested with Quadro 570, using dual link cable)? Also I just checked, the 3D Vision Pro is said to support the Quadro 570, on Windows XP (which is what we're using).
I already tried fiddling with the 3D settings in the control panel, but no avail.
Not the case.
[url="http://www.xbitlabs.com/articles/multimedia/display/nvidia-gf-3d-vision_5.html#sect0"]http://www.xbitlabs.com/articles/multimedi...on_5.html#sect0[/url]
Not the case.
http://www.xbitlabs.com/articles/multimedi...on_5.html#sect0
Not the case.
[url="http://www.xbitlabs.com/articles/multimedia/display/nvidia-gf-3d-vision_5.html#sect0"]http://www.xbitlabs.com/articles/multimedi...on_5.html#sect0[/url]
Not the case.
http://www.xbitlabs.com/articles/multimedi...on_5.html#sect0
[attachment=18439:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[attachment=18439:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[attachment=23938:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
[attachment=23938:LCD_LEFT.png]
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?[/quote]
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?[/quote]
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
Left and right are the signals on the shutters (before we did the hardware mods), green is signal from pixel measured with photo sensor; high signal = shutter open.
Remember I'm not talking about nVidia glasses here.
I saw the image in your link, that is how it looks like now with hardware mod.
Sole problem is the LCD writes line per line: how do I tell the GPU/monitor to use 3D mode (or whatever it's called), so that the enitre screen (ie all pixels at once) gets updated within 8mSec?
What? You confuse me, no "at once" pixel updates there, heh. Yeah, field sequential would be the next level of LCD technology, but TN is too slow for that. You have to use the glasses to mask the defects, just like the xbit article says.
I think you shoot for a "bearable flicker" result then, some ghosting residue would still remain. I sold my 2233rz in favor of DLP (zero flicker, zero ghost) , but you still see ppl complaining here.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
ok now you confuse me :)
so you are saying that, when using the 3D vision kit with the 2233rz:
- the screen does NOT write all pixels at the same time (is it even capable to?)
- the shutters are open for about 3mSec each 16mSec
- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?
- in other words, there is no way to have no ghosting?
this scenario is exactly what we have now: we alternate between one wite frame and one black frame. Left shutter opens for some mSec on left frame, vice-versa for right eye. Ideally (or as is the case on a crt or DLP), the left eye sees white image only, right frame sees black one. What we have now is, when looking at the top of the screen with the left eye, we see white but it degrades into black looking towards the bottom (because those pixels are not yet lit).
So I thought there was some mode on the card/screen that gets around this, but there is none?
let me know if this is not clear, I can show more scope screens showing what happens.
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
[quote]- the screen does NOT write all pixels at the same time[/quote] ( indeed, top down)
[quote](is it even capable to?)[/quote]( no ) [quote]- the shutters are open for about 3mSec each 16mSec[/quote]( more like 1.5 - 2 )
[quote]- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?[/quote]
[url="http://www.youtube.com/watch?v=FAQh6bREFqM"]http://www.youtube.com/watch?v=FAQh6bREFqM[/url]
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
( indeed, top down)
( no ) ( more like 1.5 - 2 )
" rel="nofollow" target = "_blank">
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
[quote]- the screen does NOT write all pixels at the same time[/quote] ( indeed, top down)
[quote](is it even capable to?)[/quote]( no ) [quote]- the shutters are open for about 3mSec each 16mSec[/quote]( more like 1.5 - 2 )
[quote]- suppose the left shutter opens at the time the very first pixel is written, the left eye correctly sees that pixel, but will not see pixels at the bottom, since they are written about 8mSec later?[/quote]
[url="http://www.youtube.com/watch?v=FAQh6bREFqM"]http://www.youtube.com/watch?v=FAQh6bREFqM[/url]
There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:
( indeed, top down)
( no ) ( more like 1.5 - 2 )
" rel="nofollow" target = "_blank">
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
[quote]There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:[/quote]
I'd like to see what 'they' propose then.. imo technically impossible.
Thanks for your replies!
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
I'd like to see what 'they' propose then.. imo technically impossible.
Thanks for your replies!
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
[quote]There are threads here about "top of the screen ghosting" , they still beleive it can be compensated for... I don't . :rolleyes:[/quote]
I'd like to see what 'they' propose then.. imo technically impossible.
Thanks for your replies!
wow, what an enlightenment. I really didn't know that..
So basically the nVidia promise of 3D with LCD is total bs ;p. Too bad, we really had our hopes set on this solution (well, as said, for very small images we can tune the shutters to have almost no ghosting, but the disaster remains for larger ones.. for our application, there can be NO ghosting at all)
DLP might be the next option... But, it has color smearing aka rainbow effcet for fast movements; Ok this is better with 3DLP but those prices are really steep.
I'd like to see what 'they' propose then.. imo technically impossible.
Thanks for your replies!