Home Theatre 3D Stereoscopic Projection + DIY Silver Screen for 3D

Hey all,

www.stereoscopic3dmovies.com has some great 3D movies in blu-ray and dvd, plus awesome deals on 3dtv's.

I was wondering if there are any experienced members in this forum who have built their own home theatre setup for 3D stereoscopic content using the passive polarization method. There were a few things I could use some help with. Before posting this message I had researched all over the internet, in this forum, googling, the works but I could not find the answers or I should say the right 'materials' I need to build this home theatre. If there have already been topics about this on the forum that I may have missed, I apologize and I hope you don't mind directing me to those threads. This is going to be a long post so I hope people don't mind reading a lot.

I'm building my first home theatre 3D stereoscopic projection room. I will be getting a couple of Optoma HD7100 projectors. There is a review of it here, http://www.projectorreviews.com/optoma/hd7100/. I will use them with 2 linear polarized filters in front of the projector lens that will be projected onto a 140" (diagonal) silver screen with a pair of linear polarized glasses that you wear to watch the 3D content. This theatre room will be in a light controlled dark room. I've researched about the differences between the linear and circular polarizer's but the differences are very small in terms of 3D quality and the price in comparison is huge. So I will be sticking with the linear polarization method for now and maybe upgrade to circular in the future.

Before going on I would like to mention that this whole setup is for the average joe, a poor-man's theatre room, and a do-it-yourself as much as you can to save some bucks project. So the goal is really to find the best and cheapest material to get almost similar (or hopefully identical/superior) results from professional products.

One of the issues I have are finding the best polarizer materials for the filter and 3D glasses that is made of great quality and is relatively cheap. The goal is to achieve as little ghosting as possible. There were a number of online stores I found that sell cheap polarizer material. Here are a few:

http://polarization.com/
http://www.3dstereo.com/viewmaster/pj-pfilt-3x3.html
http://www.3dlens.com/shop/polarizer.php
http://www.berezin.com/3d/3dglasses.htm#Polarized
http://www.studio3d.com/pages/store.html

Does anyone have any experience with any of these online stores and can comment on the quality of their polarizer products? Another solution I found on the net was to buy polarizer filters that are used with photo cameras. I found this solution here, http://www.scec.org/geowall/filters.html. In trying to achieve the best possible quality and the least amount of ghosting (cross-talk) when viewing 3D content. Which polarizer would be the best? The filters that are used for photo cameras? Or from one of the links above? I read that if you use different polarizer's for the filters then the ones used on the 3D glasses, that this will add to the ghosting effect. So if this is true, this would mean that using the filters used for camera lens wouldn't be the best idea, because the polarizer on the 3D glasses would be different. Someone can correct me if I'm wrong.

The other issue is building your own silver screen for 3D. I don't have the budget to spend $300-1000 on a readymade silver screen from professional companies. The best solution and possibly the cheapest depending on the size of your screen if you were to buy a professional made product was the 'Ultra Silver 3D' paint from Goosystems (www.goosystems.com). This product looks great and seems to work really well. But it's still a few hundred too expensive for me. Just for the sake of this thread I will post up some places where you can buy readymade professional silver screens for anyone who does have the money to spend on it.

http://www.paintonscreen.com/index.html
http://www.silverfabric3d.de/html/sf_silver3d.htm
http://www.lighthouseprojection.com/index.html
http://www.berezin.com/3d/screens.htm
http://t-works.en.ecplaza.net/product.asp
http://www.stewartfilm.com/
http://www.harkness-screens.us/ss_3d_spectral240.htm
http://www.dalite.com/

I came across two extremely helpful and inspiring links on the internet about building your own 3D projector and silver screen from scratch.

http://www.lumenlab.com/forums/index...33&mode=linear
http://www.allinbox.com/vp3d/vp3d.htm (in French, use babelfish to translate)

They did a great job explaining everything in detail. One of them painted their wall to use as a silver screen and the other used a special silver fabric. The best type of paint to use for a silver screen is apparently a white metallic paint, or essentially any kind of metal paint which have polarization properties. Another tip I found was to use a matte paint over the silver screen to get rid of most or all of the unwanted bright hotspots. But would this effect the polarization of the screen? You can even use silver aerosol paint spray cans to make the silver screen with decent results. Another person on the internet (forgot where) mentioned he used silver nylon used to cover vehicles that seemed to have worked very well. I have not been able to confirm any of this myself yet, just simply reading what other people have done with some results.

I have yet to experiment all the different types of silver paints/fabrics to find the best one to use as a silver screen for 3D. I was hoping there would be someone on the forum who could point us to a specific kind of paint or fabric that they have used that seems to work really well with minimal to zero ghosting. That they can also find in your local hardware/paint/fabric store. In these forums I found many people talking about specific types of paints to use like the 'Behr Silver Screen' or the 'Black Widow PFG' etc. Hopefully we can create a similar thread here except for 3D silver screens specifically.

I would really appreciate any kind of help that anyone can offer on this topic/project. I will continue to post my own progress with building my home theatre 3D setup and will post any useful information I may come across or find.

www.stereoscopic3dmovies.com has some great 3D movies in blu-ray and dvd, plus awesome deals on 3dtv's.

Cheers,
Varinder

Hey guys,

I've been posting up my progress building this home theatre setup at a couple places. I was hoping maybe someone from here can shed some light on this topic if they've had any experience building a 3D stereoscopic projection theatre.

http://movies.groups.yahoo.com/group/3dtv/message/18981
http://www.mtbs3d.com/phpBB/viewtopic.php?f=26&t=2569

I'm not sure if you have to register to see the threads however.

I'm having a bit of a hard time deciding which of these 2
projectors to get, the Optoma HD7100 which has great lens shift
capabilities which would make it very easy to align the left/right
images. Or the, Sharp Z3000 which is superior in picture quality with
better contrast and brightness compared to the HD7100 but does not
have any lens shift options besides 'digital keystone correction'.
Those are the main differences.

Will using the digital keystone correction on the Z3000 ruin the 3D
effect? If not, i would prefer to go with a projector with superior
picture quality.

Appreciate any help, thanks.
-Varinder

Hey guys,

I completed my DIY 3D home theatre setup awhile ago. But I've been so busy working on my own 3D film I haven't had time to post up a really big post about how I made my entire setup, so others who are interested have a good idea what's needed to make their very own 3D setup. I hope to post this up some time soon.

I think people will be surprised how easy it is to make your own 3D home theatre room.

By the way, I agree that anaglyph is a pretty good format to view 3D nowadays, but it's not nearly as good as the polarized method used by Real D and IMAX. I'll be posting up screenshots as well so people can see what I see in 3D. It's pretty damn awesome.

In terms of content, there isn't too much out there. But that will quickly changing as 3D becomes more popular. There are some great sites that sell quite a number of full colored 3D films. I hope its ok to post these sites I'm not too sure. http://underground3dmovies.com/
http://www.3d-geek.net/

There may be a lack of movie content, but any PC game works in 3D. I've played a number of games in 3D like Call of Duty 4, Fallout 3, Counter-Strike, Gears of War, etc. Extraordinary in 3D. Visit www.iz3d.com for their drivers that will support your dual projector system. These guys have really awesome up-to-date support for 3D drivers.

Hope this helps.

Cheers,
Varinder

Hey guys,

Early on in the year I wanted to build my very own 3D home theatre and there were a few challenges I had to face while trying to build my own 3D theatre. But, after a ton of research and going through the whole process of building one, I finally completed the 3D theatre over a month ago. Aside from the few challenges I faced that can be easily avoided or can be prepared for, it's very easy to make your very own 3D theatre at home.

I'm a giant 3D enthusiast as well as a passionate 3D filmmaker and I'd like to help get the word out there that 3D is the next big thing. For gaming and movies. The problem with 3D today is that there isn't a lot of content out there, but that will soon change by the end of this year. More and more people are getting into this 3D hype, major Hollywood studios, game developers, some of the biggest filmmakers in the world have made the permanent switch to 3D and for good reason. So, if you want to be one of the early adopters of this new wave of technology and the way things are meant to be seen and experienced. Here's a very detailed instruction on how you can build your very own 3D theatre at home.

Now before I go on, I should mention that there are a number of ways you can view 3D. I recommend going on google for a bit and research around on all the different formats you can see 3D content. The method I'll be using is known as passive stereo, it's a similar method used by IMAX.

I was planning to take really cool 3D photos of my whole setup as well as 3D photos of the 3D content the way I see it from where I sit. But I don't have my camera available for that so I will have to upload them next time, hopefully next week sometime. So for now I will have to post up crappy pictures taken with my phone.

What you need:

2 x Projectors
(I have the Marantz VP8600)
You will need two projectors that are preferably identical in make and model. The main reason that you will want to have two identical projectors is that when you project the images out of the two projectors that the colors, the brightness, contrast, etc are the exact same. That way each eye is getting the same information. When each eye is seeing something different, like the colors, one projector is brighter or darker than the other. This will produce headaches for the viewer and the 3D image will look wrong.

How many Lumens do you need? The higher the better of course, but what would be a high amount of lumens? Well, let me mention that the projectors I have are only 800 lumens. Now that seems pretty damn low right. But, after I did an intense amount of research on projectors. I realized that the amount of lumens that most if not all projectors out there state they have are quite a bit exaggerated. So, I prefer not to even look at how many lumens a particular projector has. The best thing you can do is check out as many reviews on a projector you are interested in and see what people say about the brightness level. Let me tell you that the 800 lumens my projector can kick out is pretty damn bright and I'm very pleased with the results. But again, everyone will have their own personal preference. So what I think is bright, might not be bright enough for some. So always take that into consideration when checking out reviews.

There is one important factor you should keep in mind when choosing a projector for 3D. When you are using the passive stereo method, it's hard to determine how much light you'll be losing exactly but it's safe to bet around 50% of the light coming out of your projector when it travels through a polarized filter, bounces off a silver screen and going through another polarized filter that you'll be wearing, the 3D glasses. So for 3D, brightness and lumens pay a much more important role than they normally would for 2D viewing.

DLP or LCD? Once again, it comes down to personal preference. DLP's to me have nice contrast and vivid colors, while LCD's offer a huge amount of lumens and brightness. There is a huge advantage and disadvantage with LCD projectors when it comes to 3D. The disadvantage is that some lcd projectors may not work with a passive stereo method. Because some lcd projectors use some kind of polarization mechanism to direct the light out of the projector and this will have a negative effect on the polarization setup for 3D. However, one major advantage lcd projectors have is that if you do find an lcd projector that works with the passive stereo method. If money is no issue, you can buy these fairly expensive polarized filters called StereoPol filters (or SPARS) that allow a lot more light to pass through which would allow for a much brighter image. Compared to regular polarized filters, you will only lose around 25% of the light. Money was an issue for me and I did not know which lcd projectors would work with the passive polarization method so I opted for a DLP projector. Also because I prefer nicer contrast and colors over brightness/lumens, others may prefer it the other way around.

A huge bonus that will save you a lot of trouble when aligning both of your projectors so each image is perfectly on top of each other when its projected on the silver screen. Look for a projector that can do both vertical and horizontal lens shift that physically/mechanically moves the lens. This will help you out a lot and you won't have any keystone issues when aligning the two projectors. Try to avoid using the digital keystone correction or digital lens shift. Just avoid anything that you can 'digitally' change from the menu on your projector. This will contribute to weird artifacts in your image which will make your 3D look wrong as well as giving you possible headaches.

1 x Silver Screen
(The name of the silver fabric I found is called "Monroe" used over polyurethane.)
The second most important thing to consider once you've chosen your projectors is the silver screen you need to have to project the image on to. Why a silver screen rather than a normal white or grey screen? In order for the two images being projected by the two projectors to go into the correct eye, we need to direct the light to where we want it to go using polarization. Normal white and grey screens do not have any (or very little) 'polarization properties' on the screen. So when you project the images out of the projectors through the polarized filters and you project it at the white or grey screen. The polarized light information won't be able to bounce off the screen and enter through the 3D glasses you'll be wearing and you won't see the 3D effect. What you'll end up seeing is a double-image on the screen. Silver screens retain the polarization properties of the light as it hits the screen and bounces the light to the correct eye letting you see a 3D image.

The higher the polarization properties on the silver screen, the lower the chance of seeing any 'ghosting-effect' also known as 'cross-talk'. The ghosting-effect is when you see both the images when you're watching something in 3D, I'm sure you've noticed this at times during a 3d film. The reason this happens is because, the information that was supposed to only go into your left eye for example, is leaking a bit into your right eye. So one of your eyes (maybe both), are receiving both the images into one eye, when it's only supposed to get one image. Just like your real eyes, each of our eyes sees its own point of view of the world and our brains combine the two and we see 3D, depth. If one of the eyes for some odd reason gets the same signal as the other eye, we would be seeing double and not a single 3D view. That would be weird huh.

Should you buy a professional grade silver screen or make your own? If you got the money, get a professional grade silver screen. Stewart Film Screens offer one of the best silver screens in the world, but they are also extremely expensive. There are a number of different companies out there that produce awesome silver screens and range in price. You can ask for a small sample from most of these companies and compare their screens and choose which one you think is the best or most bang for your buck.

However, If you're like me and don't have a lot of money to spend on expensive pro silver screens just yet and like the do-it-yourself motto. Then there's also an extremely inexpensive way of building your own silver screen and the results in the end are incredible considering the amount you'll have saved compared to buying one pre-made. In the end it only cost me $50 canadian to find a silver fabric to use as the 135" screen plus $20 canadian for the wood to be used as the frame. I've compared the silver fabric I found with most of the well known professional silver screens out there and it holds up against them especially when you compare the price and quality.

Now, in order to find the silver fabric I ended up using, I did have to go through a bit of work to find it. I went to a couple of local fabric stores, bought a ton of silver fabric samples I thought might work. A great way to test out how well the polarization properties hold up in the silver fabrics is by taking a pair of 3D polarized glasses and a flashlight. Shine the flashlight at the silver fabric, hold the 3d glasses in front of the fabric where the flashlight is shining and rotate the 3D glasses and see how well the 3D glasses block and lets light through. If your able to rotate the glasses so it goes completely black, you've found a pretty good silver fabric that has great polarization properties. But that's only half the battle, sure the polarization is great, but what about when you project an image on this silver fabric? How good does the image look? Well again, that depends on you and what you find acceptable. Before I found the perfect silver screen, I had spent maybe $30-40 on samples, not too bad.

One additional problem I faced with the 'perfect' silver screen I found was that it had a very ugly looking bright hot spot on the screen due to the reflective properties of the silver fabric. I could see the bright white light coming from the projector on my screen and it was just unacceptable. Luckily I was able to find a quick and easy solution to this. I went to my local home depot store and grabbed an aerosol spray can called Tremclad Clear with a Satin shine. I sprayed this over my entire screen and there goes my hotspot, now it was perfect and ready to be used.

2 x Polarized Filters
There are two main types of polarized filters. Linear and circular. A quick google search on these two filter types will teach you everything you need to know about how they work with accordance to light. IMAX uses linear polarized filters. RealD uses circular. The difference? With linear polarizers, because of the way light travels through them, you can't tilt your head while you're watching the movie or else the 3D effect will be lost. You'll be sending the wrong information to both eyes so the illusion won't work anymore. Circular filters let you tilt your head around a lot more without having any negative effect on the 3D imagery. This may not be 100% true but, linear polarized filters produce less ghosting (cross-talk) than circular polarized filters. From my testing between the two I opted for linear polarized filters because of the minimal ghosting effect. Not only that, linear polarized filters and glasses are much cheaper than circular. And who really cares about not being able to tilt your head, I don't normally find myself watching a movie or playing a game with my head tilted 30-40 degrees.

There are a number of places you can buy these filters on the net, google is your friend. I have yet to buy a proper pair of linear polarized filters so at the moment I'm using a pair of cut up 3D glasses and put them on top of the lens of my projectors, as you can see in the pics.

Looks pretty professional right? Yeah, I know it sucks. But hey, the point is, using even simple 3d glasses as your filters for 3D still works really really well. Some brands and types are better than others that allow more light to get through the filters as well as less ghosting. But, the biggest factor that will determine how much ghosting you see will be with the silver screen. So, spend your money on a solid screen first than get a decent pair of filters.

This may or may not be obvious but just to be clear here. You can't use linear polarized filters on your projectors and wear a pair of circular polarized 3D glasses or vice versa. Just won't work. Your filters and 3d glasses have to match.

Optional Equipment (if necessary):

A Mirror
If you have a small room, or a projector that has a long throw range like mine does and you're not getting the screen size you were hoping to get because you don't have enough room. Well to solve that issue, you can use a mirror to bounce the projected image coming from the projector to the screen like the setup I have here in the pics I posted up.

A few things to know about using mirrors to bounce the image around. Use 'front surface mirrors'. These mirrors will retain most of the light as it bounces off to the screen. You will also avoid seeing a double image. Most of the mirrors people use in their homes are 'rear surface mirrors'. Where the mirror is in the back covered by a thin layer of clear plastic so it gets protected by scratches and such. Because of the plastic layer, when light hits the mirror, it has to go through the plastic layer then reaches the rear mirror and bounces back again through the plastic to the screen. This will create a double image out of your single image. Some websites will show you some good diagrams of how that looks. Because front surface mirrors don't have that protective plastic layer. It's very fragile and easy to scratch. Not only that, front surface mirrors are usually quite expensive. But, once again if you search around on google, there are a number of tutorials people have posted on how to make your cheap rear surface mirror into a front surface mirror.

I was planning on using one of my rear surface mirrors and using one of the tutorials to turn it into a front mirror. But, when I tested out how well the rear surface mirror worked. I was surprised with the results. I barely noticed this 'double-image' effect that's supposed to occur with rear surface mirrors. I had to stand 1-2 feet in front of the screen to see what I thought was the double-image effect. So, I decided the rear surface mirror was good enough for now instead of going through the hassle of making a front surface mirror. I probably lost a bit of light as well using the rear surface because of the plastic layer. But I was pretty happy with the results for now.

The optimum position and angle of the mirror should be placed at the center of the screen at a 45-degree angle. It is also better to angle the mirror vertically and not horizontally. If you angle it horizontally you will introduce focus problems where one side of the screen is clear and it gradually goes out of focus as it goes across the screen to the other end.

Finished, 3D-time!

So, that's it, it's that easy. It may seem a bit daunting or complicated at first if your new to 3D, but it's very easy to understand it all over a short time. It's very basic stuff. If you check out the 3D I'm seeing, it's pretty awesome with the setup I have and it's not even complete yet. I still have to make a better stand for my projectors instead of the thing its sitting on right now shown in the picture. The way I placed the filters on my projectors isn't a good idea and I'm planning to build a proper filter holder when I get better filters. I'm still using some crappy 3d glasses that I'm using as my polarized filters. So if I purchased better filters I would get a much brighter image plus a lot less ghosting which I'm not getting much of anyway. I'm using a rear surface mirror, so I'm losing light there. If you have the money to buy a front surface mirror or to make one. You'll be able to achieve better lighting as well as low ghosting. And the silver screen itself is hand-made used by fabrics found by your local fabric store. Imagine how much better a professional grade silver screen would be. I just hope my setup proves that you can make a very cheap, dirty, and affordable 3D home theatre with pretty kickass results. And if you got the money to buy higher grade equipment, you'll get an even better experience and quality. Once I complete my setup properly, I will post up more pictures again.

Total cost for my 3D theatre using passive stereo setup:
2x Projectors = $2000 ($1000 per projector)

DIY Silver screen
Silver fabric = $50
Wood frame = $10
Black fabric for frame = $10
Searching for right fabric = $30

Polarized filters = $1 for a pair of 3d glasses

What you can do with your new 3D setup:

3D Gaming
A company known as iZ3D specializes in 3D hardware and software. These guys are all about giving the pc gamer the best 3D experience and they have up-to-date support for your latest drivers. With their drivers you can play almost any game in 3D. If your using a passive dual projector 3D setup, you will have to purchase the "Dual Output" drivers from these guys. You can find more info on them here www.iz3d.com.

3D Movies
A very well known video player appropriately called Stereoscopic Player from www.3dtv.at is what most people use to watch 3D content. Where can you find 3D content? It's out there, but it's hard to find as not many people make 3D content yet. But there are a couple guys who specialize in turning 3D films that were released in anaglyph (red/blue format) and converted them into full color 3D films that you can use with your dual projector setup. Check these sites out for more info:
http://underground3dmovies.com/
www.3d-geek.net/

3D Images
Another well known program called Stereo Photo Maker is used to view your 3D images which you can download for free here http://stereo.jpn.org/eng/stphmkr/. Fortunately there's a lot of people on the internet that have posted tons of really awesome 3D images. I highly recommend checking them out.

The Future of 3D!?
3D bluray's are in the works and may start to come out by the end of this year.

3D televised broadcasts such as sports shows are in the works.

Playstation 3 and Xbox 360 have 3D games in the works. Including James Cameron's next big epic film Avatar which is being made into a 3D game by Ubisoft.

A company called NEXT3D (www.next3d.com) is preparing an incredible service on almost every system out there from the PS3 and Xbox 360 consoles to the PC. With this awesome service you can download a number of 3D films like IMAX 3D films to user created content that you can watch easily on your 3D setup.

There are a lot of other exciting stories out there that is bringing 3D into the mainstream day by day. 3D will no longer be regarded as a gimmick or a fad that'll breeze away over a short time like it did before many years ago. 3D is here to stay and it is the next natural evolutionary step to the way we see all types of visual content. Be it movies, television, gaming, working on your computer or using your cell-phone.

I hope this tutorial has been helpful and attracts some more people into 3D and helping them understand how it all works. If there's something I forgot to mention or something that wasn't made clear. Let me know and I'll get back to you as soon as I can.

Varinder C.
devilry.singh@gmail.com

Hello arn0,

To answer your other questions:

does the HR (such as 1080p) make a difference?
- In regards to 3D, there is no difference. But all the other advantages with a higher resolution still holds like better image quality. Which may give you a more immersive experience due to the more vivid picture quality.

is polarization the best way to produce 3d without headache for the spectators?
- I've owned a 3D-ready DLP tv with a pair of shutter glasses and I found that when I watched 3d on my dual projector setup using passive stereo. I was able to view the 3D for a much longer time, almost as much as normal 2d viewing. It seemed easier on the eyes and mind with a passive setup compared to an active setup like shutter glasses.

However, another factor and just as important that leads to headaches for the viewer is how the 3d content was filmed. If it was properly filmed, the two left/right images are not too separated as well as no vertical disparity in the images. This will give you a much more pleasing 3D experience.

when recording in 3d, how do you align the 2 camcorders?
- You will have to build a special rig that can hold your 2 camcorders perfectly aligned vertically. There are some companies out there that make these special rigs for setting up 2 cameras together that you can buy or you'll have to make it yourself. There are a number of methods, using a beamsplitter or side-by-side. For my first 3D film, I'm simply using 1 digital slr photo camera and I built my own slide bar so that I can take the left and right images using the 'cha-cha' method. It's the exact same method that was used for filming the 3D movie Coraline. This is a bit of a complicated question to answer simply. So I recommend doing some research on the net and compiling some facts on how you can make or buy your own rig to align your 2 camcorders.

how do you synhronise the 2 video and what is the impact on the 3D if there is a small error?
- I don't have a lot of experience personally on this yet. I won't be building my own 2 camera 3d rig (or buying one) until later in the year. But from what I've heard people say about the negative impact on the 3d effect if your 2 cameras are not perfectly synced in time. Maybe a couple frames off might be ok and can still be watchable in 3D without much headache. But it's best to avoid it at all costs and sync your 2 cameras as best you can. You should read up on a device called a LANC shepherd pro. This device is needed and paired with a couple of sony camcorders to sync the two cameras perfectly.

what to do with the 2nd sound recorded by the 2nd camcorder?
- I guess you can get rid of it since both cameras are recording the exact same sound.

what software do you use to build the movie / project ?
- I will be using Adobe after effects and Eyeon Fusion to work on the 3D shots and then bring them into adobe premiere for final editing.

globally, is it valuable to invest in this 2 projectors 3d system compared to alternatives such as the "DepthQ-WXGA HD 3D Video Projector" ?
- At the moment I think it's still a lot more feasible to purchase two projectors than one projector like the depthq. It only cost me $1000 per projector. From what I can see the depthq is still around $5000-6000+ compared to $2000 I spent for two projectors. Also, I don't think passive stereo works with the depthq. So, you will have to buy expensive shutter glasses and that will also limit your audience. Since with passive stereo you can have as many people you want watching your 3d content depending on your screen size and room space as well. If you prefer active shutter glasses and buying 2 projectors might cost as much as a single depthq hd projector, maybe go with the depthq if you're in that situation.

Hope this helps, cheers.

-Varinder

Hey Marja,

I had a feeling the next question would have someone asking about the computer specs.

To run 3D you really don't need anything special. You just need a relatively fast CPU that can handle HD content smoothly. I think now a day's most computers out there can run HD content fairly easily now. With the video card, you'll rather want to buy 1 really good one that has a lot of inputs to use or multiple video cards on one motherboard.

If you're looking to project 2 projectors + 1 monitor, it's fairly simple to achieve that. It's exactly what you think you would have to do. Simply plug in your extra monitor into one of the empty inputs in your video card or cards and make it act as the third monitor through your PC.

It's that simple and straight forward, there's nothing to it. Here's a look at what I have and I have absolutely no problems.

CPU: Intel Xeon E5420 Quad 2.5ghz
Memory: 8GB's, 4 sticks of 2gb's.
Video card: EVGA Nvidia 9800 GX2
O/S: Windows Vista X64

My video card has 2 dvi inputs + 1 hdmi input. I have both of my projectors connected to both dvi inputs. I go into the nvidia control panel, make both projectors act as separate monitors and there you go. It's just like setting up dual monitors side-by-side. Except now your using dual projectors overlapped on top of each other and technically seeing just 1 screen.

Hopefully this gives you a good idea of what you need if you're looking to run things smoothly. I'm not a computer expert but you can probably manage with even lower specs than what I have. But I bought this setup back in September and I bet there's way better stuff out there for way cheaper now. So I wouldn't think you should have too much trouble finding a fast computer to watch or play your 3D content.

If you need more help, let me know.

-Varinder