[DIY] "Passive Projection , How To" updated + imag
Posted: Tue Jul 17, 2007 4:43 pm
Yes, I am aiming for the record on "times edited" here
Since I just finished my passive setup at last, here an overview that hopefully may help someone and promote the use of Stereo 3D. This is an attempt to sort of giveback for all the good advices people have given me. Maybe someone will have good use for the info herein.
Passive 3D:
- Necessary parts
-Projectors
-Silverscreen
-Filters
-Frame
-Cables
- Software
-Nvidia Stereo driver
-Nhancer
-Dragontools
- Applications
-Games
-Movies
- Absolute must reads
-Advisol page by Yitzhak Weissman
- My pc
Let's start with the necessary parts:
Projectors
There is quite some info on the net about projectors. the most blatant error quite commonly seen is that all LCD's won't work. This is quite wrong. Even though LCD is pre-polarized, usually this is in a way that doesn't inhibit further polarization in 2 distinct angles for the projectors. Just make sure to check it by using 2 cheap polarizers (see shops). Furthermore, special filters (SIlverFabric.com) can be applied to LCD's that use the internal polarization in order to reach very high throughputs (normal filters cut intensity to ~40%). Thise filters are expensive though, and will probably not decrease percepted crosstalk much.
Make sure you use the exact same projectors. It will look better for a whole range of reasons. (Color, signal delay, intensity etc) Wide screen projectors are preferable imho, for stereo 3D 2 images get placed on top of eachother and displaced in the horizontal plane. Widescreen results in less % of problems at edges. Hard to explain, trust me on this? Hmm wait, a way to see it is, take a 10 pixel high and 2000 pixel wide projector (I know they don't exist ofcourse), S-3D would work on this, no problem. Other way around, a 10 pixel wide and 2000 pixel high projector would give crappy S-3D results.
I used a Hitachi PJ-TX 100 and the newer but highly similar Hitachi PJ-TX 300. 16:9 widescreen, 1280-720 pixels native, lense shift, super short throw range.
Mounting issues depend on the specific projectors used. If you have "lense shift" on the projector, life becomes a whole lot easier. There is no need for tilting the projector etc anymore to make both projectors project at the same spot. Lense shift will just, errrr... shift the lense in the beam which will move the projected image nicely without any keystoning. Works perfect and takes away alignment issue. So I managed to get away with this very cheap and easy solution:
Getting rid of the heat of the projectors was an issue for me, since my 3D setup is in the attic. (we are renting the place for just a few years btw, so I don't care about looks and style etc, I may do it nicer later)
But there was a super solution just 2 meters away, the built in air refreshing system usually built in newer houses. It had one not connected inlet, so I just took a flexible hose, a plastic corner end, and voila, all the heat my projectors manage to output, gets sucked away right at their exhaust (on the side, not visible) Perfect
Silverscreen
I wrote a bit about my experience with Silverscreen samples earlier, a short summary:
Silverfabric, Harkness Hall and Stewart all produce good screens. A very crude estimate of prices is: Harkness is 2x more expensive than Silverfabric and Stewart is 2x more expensive than Harkness. (yes I asked for prices). I personally think Harkness and Stwart are highly similar products, both in materials used (hard to keep them apart) and in optical properties. In games and I suspect movies as well, the crosstalk or "ghosting" from all screens will be small to unnoticable. However, Stewart and Harkness are the best. My main problem with those 2 are the price, and the type of material. It if quite prone to for instance denting.
However, stupid me, managed to drop my Silverfabric screen, and ow yes, that left quite an amount of marks. (imagine me cursing for quite a while). Stretching it quite tightly got rid of all of them though, and I'd think that perhaps this will also be the case for the Harkness and Stewart..
My main issue with the Silverfabric is the structure or relief of the material. It is not really noticable in games or busy backgrounds, but very noticable in similar color areas. I will never watch a movie on this screen because of this, it sparkles way too much. The Harkness and Stewart are waaaay more silky smooth.
Example of SilverFabric (left) vs Harkness (right), you can see the difference in smoothness, and it does show in even color areas, but especially in games, it doesn't disturb me at all. And I must say now, that movies are not as bad on it as I thought, it does show a bit.. but again, only on even color areas.
I paid ~300 euro for my Silverfabric, it will do for quite a while. But my eye will be set on a Harkness, and I will more thoroughly test the material soon. If you got the money to spare, get the Harkness imho. Otherwise, SilverFabric will do fine also!
Ow and btw, here a picture of the backsides of those screen samples. You can maybe see that the SilverFabric is really like fabric, and the Harkness is more of a smooth stretchy material..
Filters
Now, getting correct filters is quite a hassle. I tried photocamera filters, ordered from de-Wijs.nl, Berezin.com and from Polarization.com. The photocamera filter was superior, the polarization.com filters were extremely cheap and definately sufficient, from de-wijs.nl were quite bad and the ones from Berezin never arrived After more than a month... odd, since the company is often quoted. I e-mailed them 4 times now.
The filters I got were cheap. Like 30 dollar for 2 A4 sized sheets. And they are perfect with extinction factors in the thousands. (say 3000:1, so when 2 are crossed only 0.3 promille is transmitted.) If you want fancy glass ones with rings etc around them.. expect to pay 100's of $'s. The thing to remember though, is that the silverscreen sucks big time in polarization respect. It will be like 100:1 extinction factor, so there is only so much you can do with filters. Yitzhak Weissman has a great few articles on this, see my must reads part.
Unless you want the high throughput filters from Silverfabric, I'd go for the ones polarization.com offers with the 3 mil backing or so.
Ow and by the way, linear polarized is fine. The whole 3d effect is not gone if you slightly turn your head and who games with his head tilted all the time anyway. Circular is also worse on the extinction ratio side, and you can't tilt your head that much more with those anyway.
Glasses wise I only tested the "Theme Park style", since the fancier ones never arrived from Berezin. They work fine, albeit not so fancy looking as the ones IZ3D is going to ship soon I hope.
Mounting the polarizers seemed troublesome but I stick with my dirty quick solution of the first day. Those are pvc pipe wall mounts it is in. I just cut the polarizers into shape, and put the in the mounts and put them on the hardwood of the projectormount. Bit of rotating and voila.. works fine.
Frame
Mounting the screen will need a frame. If you won't move it, I'd stretch and fix it onto a board (maybe strengthen the edges of the material with a stitched on black cloth). I needed it mobile so I ordered custom aluminium profiles and materials from Rexroth / Bosch (Rimas.nl is the supplier in the Netherlands). It cost me around 250 euro's but it is a very nice, light and pro looking frame now. I think I'll be able to demount it in minutes if 1 person helps.
Shaky cam closer up view of my custom ultralight frame
And yes it is not against the wall, also because I forgot to check if my projectors could manage to project so small, the couldn't so I had to move the frame closer by. Ops
(Ok the attic is a mess, I just spend a full day stereo gaming with my brother there.. )
Then again, if it doesn't need to be mobile, stretch it onto a triplex plate or so and look for instructions on how to properly stretch material on a frame.
Cables
Another one of those things I was very unsure about. In the end, I had 1 supercheapo DVI to HDMI cable for 13 euro's, and a quite expensive ProfiGold one for 110 euro's. Both 10 meters long. I was afraid of the so called digital noise, and bad pixel throughput on the cheap one. But they both give a perfect image! (another 95 euro's wasted I guess)
(check cable differences in the first projectors image at beginning of post)
In the future, I won't be so hasty with "pro" cables
Also, my pc is not on the attic, it is one floor below. To do that I use bluetooth long distance mouse and keyboard, a hole in the floor for the surround sound wires and these 10 meter DVI cables.
Software
Not yet written, but there is alot of info floating around. Take some time to find it all..
Applications
Ok, passive projection is amazing. I had some doubts about ghosting etc etc.. but this setup works perfectly. Ghosting is really not an issue at all, and assuming you did your homework on "correct stereo viewing" no eye strain etc at all. I must admit though, that I can't game as long in stereo 3d as in normal 2d. I am not sure what the reason is, but it may just be the immersiveness. I am not sure if the human brain is supposed to cope with nonstop warfare, zombies, aliens, shelling etc. So I can't do it for 8 hours straight 4 - 6 hours or so is not really a problem for me..
Also, your brain may pick up the "problem" that even though the 3D is quite good, your are always, focussing (lenses of your eyes) on the screen, whether the eyes are rotated inward or straight. This is a bit unnatural I guess to them (I suppose a brain usually links rotation of the eye to more or less depth..) but well, nevermind all this. It is awesome.
So don't spend you very last dime on S-3D, but if you want a super gaming experience, this is it.
Games I tried and work perfect (copied from best games thread):
AOE3: just perfect 3D, no problems anywhere. For some reason, this one gets the strongest response from on-lookers. "It looks like playing with clay figures!"
Half Life 2 Episode 1: Ow man, real great 3D here. No HUD, no crosshair (not even the Nvidia one, doesn't work at correct depth for me). However, this is no sniping game anyway. Rock solid! I just aim with the tracer bullets. (ps: someone should mod this game, so that more guns use the bazooka's laser to aim. Would work like a charm.. and the idea applies to more games)
Call of Duty 2: Great 3D, nice snow effects etc too when enabling DX 9. Nvidia crosshair not spot on, but workable. Great title! (no HUD for me again btw)
Far Cry: HUD, crosshair etc all work flawless here, as if it was made for S-3D. What can I say.. most perfect FPS I played with S-3D.. but the other 2 are close
Oblivion: Cool 3d, but still water is either pink or 1995 style and the sky is rendered at the wrong depth (so never look up, looks weird ). Still, very cool gaming!
In these games I am changing convergence so it matches my real world setup. So I converge a point in the scene like 4 meters away. Then decrease seperation to something very small and increase convergence somewhat more (the it deviates from real world, but gives more out of screen effect). This is imho the best, when playing on a widescreen. It matches the real world thing the most and gives best 3D "fill".
Absolute must reads
For now just this one, if you want to understand passive projection better. (the numbers and details, very good read!)
http://www.advisol.co.il/Technical%20memos.html
My pc
I am running all games (no movies tried yet) smoothly with quite some options on on a:
Intel Core 2 Quad 6700 (but often single core mode on in Nhancer program)
7950 GT Nvidia card
Nvidia 94.something drivers?
I hope somebody finds a use for all this!
Since I just finished my passive setup at last, here an overview that hopefully may help someone and promote the use of Stereo 3D. This is an attempt to sort of giveback for all the good advices people have given me. Maybe someone will have good use for the info herein.
Passive 3D:
- Necessary parts
-Projectors
-Silverscreen
-Filters
-Frame
-Cables
- Software
-Nvidia Stereo driver
-Nhancer
-Dragontools
- Applications
-Games
-Movies
- Absolute must reads
-Advisol page by Yitzhak Weissman
- My pc
Let's start with the necessary parts:
Projectors
There is quite some info on the net about projectors. the most blatant error quite commonly seen is that all LCD's won't work. This is quite wrong. Even though LCD is pre-polarized, usually this is in a way that doesn't inhibit further polarization in 2 distinct angles for the projectors. Just make sure to check it by using 2 cheap polarizers (see shops). Furthermore, special filters (SIlverFabric.com) can be applied to LCD's that use the internal polarization in order to reach very high throughputs (normal filters cut intensity to ~40%). Thise filters are expensive though, and will probably not decrease percepted crosstalk much.
Make sure you use the exact same projectors. It will look better for a whole range of reasons. (Color, signal delay, intensity etc) Wide screen projectors are preferable imho, for stereo 3D 2 images get placed on top of eachother and displaced in the horizontal plane. Widescreen results in less % of problems at edges. Hard to explain, trust me on this? Hmm wait, a way to see it is, take a 10 pixel high and 2000 pixel wide projector (I know they don't exist ofcourse), S-3D would work on this, no problem. Other way around, a 10 pixel wide and 2000 pixel high projector would give crappy S-3D results.
I used a Hitachi PJ-TX 100 and the newer but highly similar Hitachi PJ-TX 300. 16:9 widescreen, 1280-720 pixels native, lense shift, super short throw range.
Mounting issues depend on the specific projectors used. If you have "lense shift" on the projector, life becomes a whole lot easier. There is no need for tilting the projector etc anymore to make both projectors project at the same spot. Lense shift will just, errrr... shift the lense in the beam which will move the projected image nicely without any keystoning. Works perfect and takes away alignment issue. So I managed to get away with this very cheap and easy solution:
Getting rid of the heat of the projectors was an issue for me, since my 3D setup is in the attic. (we are renting the place for just a few years btw, so I don't care about looks and style etc, I may do it nicer later)
But there was a super solution just 2 meters away, the built in air refreshing system usually built in newer houses. It had one not connected inlet, so I just took a flexible hose, a plastic corner end, and voila, all the heat my projectors manage to output, gets sucked away right at their exhaust (on the side, not visible) Perfect
Silverscreen
I wrote a bit about my experience with Silverscreen samples earlier, a short summary:
Silverfabric, Harkness Hall and Stewart all produce good screens. A very crude estimate of prices is: Harkness is 2x more expensive than Silverfabric and Stewart is 2x more expensive than Harkness. (yes I asked for prices). I personally think Harkness and Stwart are highly similar products, both in materials used (hard to keep them apart) and in optical properties. In games and I suspect movies as well, the crosstalk or "ghosting" from all screens will be small to unnoticable. However, Stewart and Harkness are the best. My main problem with those 2 are the price, and the type of material. It if quite prone to for instance denting.
However, stupid me, managed to drop my Silverfabric screen, and ow yes, that left quite an amount of marks. (imagine me cursing for quite a while). Stretching it quite tightly got rid of all of them though, and I'd think that perhaps this will also be the case for the Harkness and Stewart..
My main issue with the Silverfabric is the structure or relief of the material. It is not really noticable in games or busy backgrounds, but very noticable in similar color areas. I will never watch a movie on this screen because of this, it sparkles way too much. The Harkness and Stewart are waaaay more silky smooth.
Example of SilverFabric (left) vs Harkness (right), you can see the difference in smoothness, and it does show in even color areas, but especially in games, it doesn't disturb me at all. And I must say now, that movies are not as bad on it as I thought, it does show a bit.. but again, only on even color areas.
I paid ~300 euro for my Silverfabric, it will do for quite a while. But my eye will be set on a Harkness, and I will more thoroughly test the material soon. If you got the money to spare, get the Harkness imho. Otherwise, SilverFabric will do fine also!
Ow and btw, here a picture of the backsides of those screen samples. You can maybe see that the SilverFabric is really like fabric, and the Harkness is more of a smooth stretchy material..
Filters
Now, getting correct filters is quite a hassle. I tried photocamera filters, ordered from de-Wijs.nl, Berezin.com and from Polarization.com. The photocamera filter was superior, the polarization.com filters were extremely cheap and definately sufficient, from de-wijs.nl were quite bad and the ones from Berezin never arrived After more than a month... odd, since the company is often quoted. I e-mailed them 4 times now.
The filters I got were cheap. Like 30 dollar for 2 A4 sized sheets. And they are perfect with extinction factors in the thousands. (say 3000:1, so when 2 are crossed only 0.3 promille is transmitted.) If you want fancy glass ones with rings etc around them.. expect to pay 100's of $'s. The thing to remember though, is that the silverscreen sucks big time in polarization respect. It will be like 100:1 extinction factor, so there is only so much you can do with filters. Yitzhak Weissman has a great few articles on this, see my must reads part.
Unless you want the high throughput filters from Silverfabric, I'd go for the ones polarization.com offers with the 3 mil backing or so.
Ow and by the way, linear polarized is fine. The whole 3d effect is not gone if you slightly turn your head and who games with his head tilted all the time anyway. Circular is also worse on the extinction ratio side, and you can't tilt your head that much more with those anyway.
Glasses wise I only tested the "Theme Park style", since the fancier ones never arrived from Berezin. They work fine, albeit not so fancy looking as the ones IZ3D is going to ship soon I hope.
Mounting the polarizers seemed troublesome but I stick with my dirty quick solution of the first day. Those are pvc pipe wall mounts it is in. I just cut the polarizers into shape, and put the in the mounts and put them on the hardwood of the projectormount. Bit of rotating and voila.. works fine.
Frame
Mounting the screen will need a frame. If you won't move it, I'd stretch and fix it onto a board (maybe strengthen the edges of the material with a stitched on black cloth). I needed it mobile so I ordered custom aluminium profiles and materials from Rexroth / Bosch (Rimas.nl is the supplier in the Netherlands). It cost me around 250 euro's but it is a very nice, light and pro looking frame now. I think I'll be able to demount it in minutes if 1 person helps.
Shaky cam closer up view of my custom ultralight frame
And yes it is not against the wall, also because I forgot to check if my projectors could manage to project so small, the couldn't so I had to move the frame closer by. Ops
(Ok the attic is a mess, I just spend a full day stereo gaming with my brother there.. )
Then again, if it doesn't need to be mobile, stretch it onto a triplex plate or so and look for instructions on how to properly stretch material on a frame.
Cables
Another one of those things I was very unsure about. In the end, I had 1 supercheapo DVI to HDMI cable for 13 euro's, and a quite expensive ProfiGold one for 110 euro's. Both 10 meters long. I was afraid of the so called digital noise, and bad pixel throughput on the cheap one. But they both give a perfect image! (another 95 euro's wasted I guess)
(check cable differences in the first projectors image at beginning of post)
In the future, I won't be so hasty with "pro" cables
Also, my pc is not on the attic, it is one floor below. To do that I use bluetooth long distance mouse and keyboard, a hole in the floor for the surround sound wires and these 10 meter DVI cables.
Software
Not yet written, but there is alot of info floating around. Take some time to find it all..
Applications
Ok, passive projection is amazing. I had some doubts about ghosting etc etc.. but this setup works perfectly. Ghosting is really not an issue at all, and assuming you did your homework on "correct stereo viewing" no eye strain etc at all. I must admit though, that I can't game as long in stereo 3d as in normal 2d. I am not sure what the reason is, but it may just be the immersiveness. I am not sure if the human brain is supposed to cope with nonstop warfare, zombies, aliens, shelling etc. So I can't do it for 8 hours straight 4 - 6 hours or so is not really a problem for me..
Also, your brain may pick up the "problem" that even though the 3D is quite good, your are always, focussing (lenses of your eyes) on the screen, whether the eyes are rotated inward or straight. This is a bit unnatural I guess to them (I suppose a brain usually links rotation of the eye to more or less depth..) but well, nevermind all this. It is awesome.
So don't spend you very last dime on S-3D, but if you want a super gaming experience, this is it.
Games I tried and work perfect (copied from best games thread):
AOE3: just perfect 3D, no problems anywhere. For some reason, this one gets the strongest response from on-lookers. "It looks like playing with clay figures!"
Half Life 2 Episode 1: Ow man, real great 3D here. No HUD, no crosshair (not even the Nvidia one, doesn't work at correct depth for me). However, this is no sniping game anyway. Rock solid! I just aim with the tracer bullets. (ps: someone should mod this game, so that more guns use the bazooka's laser to aim. Would work like a charm.. and the idea applies to more games)
Call of Duty 2: Great 3D, nice snow effects etc too when enabling DX 9. Nvidia crosshair not spot on, but workable. Great title! (no HUD for me again btw)
Far Cry: HUD, crosshair etc all work flawless here, as if it was made for S-3D. What can I say.. most perfect FPS I played with S-3D.. but the other 2 are close
Oblivion: Cool 3d, but still water is either pink or 1995 style and the sky is rendered at the wrong depth (so never look up, looks weird ). Still, very cool gaming!
In these games I am changing convergence so it matches my real world setup. So I converge a point in the scene like 4 meters away. Then decrease seperation to something very small and increase convergence somewhat more (the it deviates from real world, but gives more out of screen effect). This is imho the best, when playing on a widescreen. It matches the real world thing the most and gives best 3D "fill".
Absolute must reads
For now just this one, if you want to understand passive projection better. (the numbers and details, very good read!)
http://www.advisol.co.il/Technical%20memos.html
My pc
I am running all games (no movies tried yet) smoothly with quite some options on on a:
Intel Core 2 Quad 6700 (but often single core mode on in Nhancer program)
7950 GT Nvidia card
Nvidia 94.something drivers?
I hope somebody finds a use for all this!