Home Theatre 3D Stereoscopic Projection + DIY Silver Screen

[ignatius]

Thanks tril!

I read the whole thing and posted a small reply.

Cheers,
Varinder

[wnielsenbb]

I got my cheap plastic polarizers and glasses from Berezin. I got 3D screen material from Harkness-Hall based on reviews. $337 for 120" diagnol and $32 for shipping. I am using an LCD projector, the Panny ae2000U, but due to the smoothscreen filter the special LCD polarizers don't work. The cheap plastic ones do though. I haven't got my second projector yet, so I haven't finished the setup. With all the 3D stuff coming out this year, it is tempting to wait. I have thought about doing Circular polarization. The nice thing about circular polarization is all the free glasses from the theater.
Warren.

[nubie]

There is a nice 100" diagonal 4:3 screen here for $63.48 http://www.provantage.com/da-lite-90618~7DALI094.htm" onclick="window.open(this.href);return false;

I don't know how the old-school da-lite silver matte suits your fancy though.


I did order a Da-Lite once, it shipped from the factory, so even if the site is sketchy you are probably going to get it shipped from the factory.

Those projectors look awesome btw

[ignatius]

Hey guys,

Thanks for posting more info about cheap solutions for building a 3D home theatre and your own experiences.

I'm nearing the end of my whole 3D home theatre project. But I've come across one final problem. The really awesome silver fabric I found that works incredibly well with 3D, has one major downside. It has a really bad hot spot from the light coming from projector. Now, I was thinking of using a clear matte finish on the silver fabric to get rid of the shiny glare. But I'm not sure if this will have a negative effective on the polarization or if it'll create ghosting due to the secondary 'plastic' coating from the matte finish.

Any help or suggestions will be very much appreciated. Thanks.

- Varinder

[wnielsenbb]

Did you try with the polarizers in place (on the projector and the glasses). They will reduce the brightness of the projector which may be enough to eliminate the hotspots. Otherwise you may need an ND2 filter.
Warren.

[Likay]

I've noticed the glare in my rig too. Spotted it first when taking pictures of the screen though.
Don't know any way to deal with it though. It's not a huge problem when gaming since you're mostly focused on the center area of the screen. That makes the phenomena become really less.

[ignatius]

Hey guys,

Thanks for posting back. I don't have proper polarizer filters, I'm just using a pair of 3D glasses at the moment in front of the projector lens. And it doesn't get rid of the hot spot, it's mainly because of the extremely reflective screen I'm using.

But, I went out and bought clear matte spray paint and sprayed it all over the screen and it worked like a charm. The hot spot is gone and it had no negative effect with the image quality or polarization. To be quite honest I wasn't thinking it was going to work, but it ended up working incredibly well. Got rid of the shine and now the screen is nice and matte.

I'm very close to completing this theatre now, just a few more days. I'll be posting up a very big post when its all done with pictures of my completed home theatre and everything I used. I hope this will help others when they start to make their own 3D home theatre solution on a tight budget. I don't think it'll get any cheaper than the route I took.

Cheers,
Varinder

[ignatius]

Hey guys,

This tutorial I wanted to write up is long overdue. I've been side tracked with a lot of other things going on in my life including a 3D film I'm working on. But here it is and I hope this helps people out.

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 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.

[ignatius]

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.

[ignatius]

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.

[ignatius]

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.

[ignatius]

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.

[ignatius]

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

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

[ignatius]

I'm working on a new stereoscopic 3D website, at the moment this is the temporary website to get the best deals 3D products from movies to tv's. click ---> 3d movies

[motorman45]

hate to be late to this thread but have you seen the omega 3d filter setup ?. its not polarizing and not Dolby, you dont need a silver screen. its been talked about on here in other threads and on avs forum.
you have a very cool setup, whats going to be on your website. ?
here is that alternative filter system

http://www.youtube.com/watch?v=RiWf_69xHW0