| Author | Message | ||
     Anonymous Rating: N/A |
Hi guys I have just built a homebrew LCD projector using a stripped down Benq 567S 16ms response time and 4000+ Lumens OHP. This gives me a 100 inch + screen. I tried the shutter glasses with the LCD unstripped and of course they wouldn't work - except at 45 degrees - else the screen was blank. So my guess is the LCDs in the shutter glasses also have a polorised sheet which when used with this LCD cuts out 100% of the light. (LCDs have polorised sheets in them). Here's the interesting bit though. Stripped down and all the filters removed and used as part of the phome brew projector the Nvidia Medical Image worked... Interesting as I thought the ghosting would be bad...but no not bad at all. More interesting still was the Test Application which worked as well. This is where things got a little problematic. As you can only configure up to a 25 inch monitor and only to a certain distance in inches away from the screen... These figures must be used to calculate the separation of the left and right eye images at particular depths in the frame. With a 100 inch 'monitor' at an 120 inch distance there was no way of accurately controlling the spearation of the images. The foreground would be fine but the images further 'into the sceen' would be separated with too great a distance. The stereo effect was ok especially giving a real sense of depth when writing or lens flare effects appeared on the screen. Contolling the separation using ctrl f3 and f4 in games would result in a passable limited depth stereo image but crank up the separation (to get a deaper image) and the effect would be lost. It would be good to hear from anyone who knows enough about how the drivers work as whether there is a work around to this separation sensitivity problem. If there is then I have a XGA 3d projector for £200! So if someone out there can help...please do as many people would like a sub £200 (with second hand parts) 3D projector solution. | ||
| Anonymous Rating: N/A |
can you give us a more detailed description on how you build it, maybe with photo's too. it would be great to have a "how to build your own projector manual" | ||
| Anonymous Rating: N/A |
Here is the main English source on the net: http://www.diyaudio.com/forums/forumdisplay.php?s=&forumid=20 Here is a German guy who has done similar: http://www.diyaudio.com/forums/showthread.php?s=&threadid=12737&highlight=benq A French guy with a pic by pic tutorial on stripping Benq lcds: http://cfeuillet.free.fr/KolimaVP.html Hope this helps. Lots of photos in the 'Post your Results Forum'. Be aware though that taking pictures of projected images in low light conditions does not give a real idea of quality... But I played Postal 2, Mafia and Morrowind with no problems. At the start of Postal 2 there are a number of household objects swirling in space. One is an unopened toy - a doll in its box - the clarity, depth and 3d effect on this one object was amazing... In any event playing games on a 100 inch diagnal screen is great the characters are almost 'real life size'... Lord of the Rings Movie was ace too. Anyone friendly with Nvidia? Would love to be able to more accurately control separation and depth calculations...Perhaps there is a way to set up a config file for each game... Or does anyone know if you can do this with Win3d or similar | ||
| Anonymous Rating: N/A |
Further investigation revealed a postal2 file in a nvstereo folder. On opening in notepad it had a number of variables in it including maxdepth 9999.0000000 and several others variables with values that must be used to calibrate the separation of objects in the frames at various depths. For instance say for an accurate 3d effect an object (a car in a game) in the frame needs to have a separation of 10 pixels difference between the left eye image and right eye image. On a on a average monitor this would be a real distance of about: 10/1024*the length of the screen (say 11 inches) which gives a real separation of 0.1 of an inch. This would not give any viewing issues - just an accurate 3d illusion. But for a screen of say 100 inches the real separation of the right and left images for that particular object in the frame would be 1 inch. Which would cause a viewing issue. Just try playing with the separation values on the driver screen to see what I mean. By increasing the separation you get a great feeling of depth until the illusion breaks down. This is what is happening when viewing games on my 100 inch screen. Anyone who has any knowledge about what the values stored in the postal2 file created by the nvidia stereo driver and saved in the nvstereo folder actually mean would be a great help. | ||
| John Billingham Rating: N/A |
This is s SWELL "high-end" "poor-person's" projection panel, Now, "STEREO" has been implied , HOW? (via shutter-glasses and "page-flipping" of the panel???? YES, the BENQ has a 16ms response time, BUT what refresh rates are achieved??? Very Curiously, John Billingham (just trying to "nail-down" some "facts") | ||
| Anonymous Rating: N/A |
Facts Its a 15inch panel Benq 567s Its running at 1024 by 768 Refresh is limited to 60-75 no/very little flicker...4 or 5 people have tried it no one has even mentioned it and they would do if it was noticable as the screen provides 90% of the light in the room Ghosting absoultely no problem Contrast ratio is 1:500 max 1:400 minimum Light is 5000 lumens powered by a Eiki 4410h ohp Screen is 80 inches by 60 inches Games are superb in 2d DVDs are a treat with the surround speakers it is just like a cinema. Blacks are as solid as you local picture palace. Colours are rich. Of course stereo effects are generated using the shutter glasses, hence the questions regarding Nvidia driver sensitivity. Trust me there are no flicker problems. The only problem seems to be with the sensitivity of the stereo controls. Enabling stereo using Ctr T you can then adjust the perception of depth using Ctr 3 (more separation) and 4 (less separation). This is fine on a monitor as one press of Ctr 3 shifts an object (car person etc) in the left frame by say 10 pixels to the left of its position on the screen for the right eye. (depending on the value in the z buffer -its depth on screen - I think) This on a monitor is only 0.1 of an inch. On my screen, which is c 10x bigger this distance in 1 inch. If use the same 2d image for each eye in one of the 3d image maker programs and separate them by a small number of pixels, the '3d like'picture seems to be on a screen receeding in from the real screen. Increase this to an inch or more and the effect breaks down as the eyes find in more difficult to be fooled. This is the problem I am trying to find a solution for as the nvidia stereo driver calculations are based on a much small monitor size and a 'fixed' viewing distance from the screen of 18inches to 2 feet. Very different from a 100inch+ screen with viewing distances of 6-12 feet.... If the issue was a 'ghosting' one then there would be really apparent blurring of the whole image on the lowest stereo setting and it simply does not exist as the images are pin sharp. More so in motion! So there you have it a £200 experiement, with one final hurdle... So co'mon guys can't someone help regarding the nvidia stereo driver? What do the config file numbers mean in the game files generated in the nvstereo folder? Someone must know. Else I'll have to work it out by trial and error. Change a value. Boot the game. See the effect. Bor-ring but do-able! | ||
| Anonymous Rating: N/A |
BTW Thanks for the interest John. I thought there would be more! | ||
| Anonymous Rating: N/A |
Well I have not had the chance to experiement but I did email the development team at Nvidia who actually replied! What great guys. For those interested here was their response: but you can by going into the registry and changing the setting called "MonitorSize" under the "Stereo3D" group(just search for it). The value is in .5" so a value of 210 would be 105". If you check the Stero property page after changing this it sould say 105" there. So a simple 'fix' after all. Perhaps anyone else who is playing on a large monitor would like to try this to get a better stereo effect.... Will let you know how this works out | ||
| Anonymous Rating: N/A |
Home made LCD Projector - with Stereo Great Posts!!!! MovLab  All ears on this now... | ||
| Anonymous Rating: N/A |
Hi, thanks for the info! I'm a newbie so this might be a stupid question but: When playing games in stereo with the shutterglasses, do you have to keep you head focused straight on the screen? Does turning your head slighly ruin the 3d image? Thanks | ||
| Anonymous Rating: N/A |
As long as your eyes are on the same hight (horizontally that is) there is no problem. If they are not, however, it ruins the picture. | ||
| Anonymous Rating: N/A |
Thanks for the response. I checked out that french page, and it looked a bit intimidating but I think I'm going to give it a shot. What kind of screen do you use? Thanks again | ||
| nonanon Rating: N/A |
u need to control stereo separation more acurately. if u use ctl f3 and f4 it decreases or increases a litle bit les than two values per presed key so try to control it thougt stereo separation inside the nv stereo propreties window(0-100 int values) for more acuracy only in the files: dont know how to change the values in the game name files(inside nvstereo.log folder in c: ), as i change the values and nothing hapens. if anybody qnows how to change this values and work in game post please. | ||
| Anonymous Rating: N/A |
"Here's the interesting bit though. Stripped down and all the filters removed and used as part of the phome brew projector the Nvidia Medical Image worked... " Can you please explain this?You actualy took out the polarizing filters of the lcd?I do not follow! I also have a diy projector with beng 557s,hqi 400w daylight temp and fine optics,(glass fresnels,ir filters,varifocal triplet etc),and it is great with 2d,better than many comercial projectors until 3000$.Please explain a bit more i am very very interested!!!Thanx. | ||
| Anonymous Rating: N/A |
The LCD polarizing filters help with contrast issues. If you try 3d with shutter glasses and that LCD then when viewing through the shutter glasses and rotating them the picture darkens and disappears and then comes back again. This infers that there is another polarized coating on the glasses themselves. Try with your home made set up. So by removing the three or four thin plastic like sheets from the LCD - you may have already done this - you remove this barrier to using the monitor for 3d or your projector for 3d... The only other issue is the separation issue of in game entities as it is easy for the brain to be fooled by a gap of 4 or 5 pixels (between left and right eye images) on a 17 inch monitor but this rises to over an inch or so for sceens 200 inches in size... Hence the need to more acurately control separation of the images. Still images are fine. Extremely fine. 3d gaming demands a lot of fiddling to get right. Try emailing Nvidia's stereo team. | ||
| Daimonion Rating: N/A |
Wow that sounds great, I have bought a overhead projector 4000 lumens and i have the 3d glasses (i have yet to strip them) i am just awaiting a bargan of a monitor to come up on ebay : ) | ||
| Daimonion Rating: N/A |
just a quick question - how do the glasses work if you remove the polarising sheet, how can they darken? might be a silly question but last time i removed a polarisation filter of an lcd, it became ivisible so how would the glasses still manage to darken? | ||
| Anonymous Rating: N/A |
Make sure that the refresh time is 16ms or below. Also check the homebrew projector forum for lcds that you can strip down. At this point I'd say pick up a cheap X1. Remove the polorised sheets on the monitor when you strip it down. Light from the screen of the projected image is not polorised so 3d glasses can work. If you do get ghosting (high response times) and you are using nvidia - trye the red blue glasses method. I'd also wait to see what the LCD modes in edims new drivers do... | ||
| MovLab Rating: N/A |
Hello Anonymous: It's Great To See This Thread Still Active!!! Do Have A Homepage, Or Site You Belong too? MovLab |
