3D Stereo

Hardware options for Stereoscopic Visualisation

The main components of a stereo 3d projection system are dependant on the type of system that you choose:


1) Active Stereo 

2) Passive Stereo 

3) Auto Stereo


There is also a Hardware Links section below.

A 2005 UCL presentation on the various technologies can be found here :


1.0) Active Stereo: Quad Buffer

For education the cost of active stereo glasses and the requirement to use more expensive "Quad Buffered" Graphics cards probably means this is not the preferred choice where groups of more than 3 or 4 will use the system at the same time.... and these days it is arguable that the perfomance and comfort of passive systems are as good if not better. On the other hand an active system just has one projector and uses a standard screen surface, so if the glasses become more affordable and sturdier then this could become an option... many current DLP's will run frame sequential stereo but not at full 60hz per channel. There is information and a list of standard DLP's capable of active/time sequential stereo here :





Just announced, and still awaiting pricing info, is the new F10 AS3D active projector from Projection Design.


Full 120hz refresh, and accepts two DVI/VGA inputs from a standard graphics card.... so will convert your standard side x side passive stereo set up to active. This could be really great for systems with only 5 - 10 adult users at a time, as the cost of the active glasses, around £100 each, and a tendency to break easily probably rules out systems with a larger audience or with children.


1.1 Active Stereo : 3D Ready / DLP Link

being edited...


1.2 Active to Passive Modulators :


being edited...

As stated above, the problem with "active" single projector systems is that you need to use expensive and often fragile glasses, that also need to be charged or have batteries replaced.... but the benefit of a single projector with no aligment issues can be worthwhile if you 

If you have been to a 3D film at the Cinema where you used RealD circular polarised glasses, then you have experienced a "cinema" quality version of the following active to passive filters that allow you to use a single projector active 3D system and place a switching filter



2) Passive stereo using polarised glasses and filters:


There are different forms of passive stereo, most people are familiar with Anaglyphic, usually using Red/Green glasses but this impairs colour and is not comfortable for prolonged use - so I don't recommend this. Much better are systems using polarising filters, there are usually two projectors, one for each "eye", which will be aligned on screen using a stacker and will have either linear or circular polarising filters in front of each of the lenses and the users wear matching polarised glasses. Choice of filters and screen surface will affect the amount of ghosting/cross talk you will see. However, with a well matched system ghosting should be hardly noticeable.



I have tested the majority of "3D" screen materials and while they do all work, some are much better than others. Image brightness, colour rendition and the amount of ghosting (crosstalk) is all affected by the choice of screen and screen/filter/projector combination.



In my opinion DLP projectors are usually best for stereo, as they usually have a higher contrast ratio, better blacks and standard polarising filters will work. However, there are many installations around the world that use LCD's - be careful though, many LCD projectors will not work with standard filters as the light source is already polarised and poor contrast ratios can lead to your blacks being mid-grey!


Stacker and Filter holders

The aim here is to be able to easily align the two projectors, this usually entails stacking the projectors on top of one another and then using the mechanical alignment features of the stacker. However, my favourite projector had a feature called 3D reform, which allowed digital alignment, making it really fast to set up... unfortunately the DLP version of these projectors has now been discontinued - we will be testing the LCD version soon :-) The requirements also vary depending on whether it is a fixed system or a portable system.



The are many possible choices here - you can choose Windows, Linux or Mac and there are applications which will work in stereo on all of these platforms. However, as a Mac user myself, I believe the new Mac Pro has a big advantage over the others, in that it is capable of running all three operating systems.... so you don't have to compromise. The most important element to get right when specifying your machine is the graphics card- this is where most of the work is done and having the fastest card with most memory that you can afford is going give you the best performance. However, you don't need to go for the expensive Nvidia Quadra cards which are advertised as having "stereo in a window" unless your application requires "Quad Buffered" mode to run.... and if it does you will also need an active to passive convertor or use active stereo - see above.


Apple Mac Pro : Suggested Minimum Specifications


Processors : Two 2.8 GHz Quad-Core Intel Xeon

RAM : 2GB is really the minimum requirement and more memory will improve performance, and with some applications also increase the size of dataset that can be handled and reduce loading times. 4 GB is usually fine. Only order the base requirement from Apple and get your additional RAM from a good third party like Crucial.

Graphics Card : Nvidia GeForce 8800 GT 512MB (2 x dual-link DVI) or if money is no problem the Nvidia Quadra FX 5600 has 1.5GB of video memory.

Hard Disks : up to four : 500GB 7200-rpm Serial ATA 3Gb/s. Larger Disks are now available.

Optical Drives : one or two : 16x SuperDrives

Both Bluetooth 2.0+EDR and AirPort Extreme



These can vary in price dramatically, for systems using DLP projectors up to 2,500lms, we have found that cheap Cokin filters are as good as any, if used with the SilverFabric screen (below). It is important to match your filters to your screen fabric to minimise ghosting.



American Paper Optics are still the best source for both paper and robust plastic theme park style glasses. They also do more expensive Aviator glasses which are to be recommended for prolonged use.


Audio System

This is down to preference and type of use.... but good audio is essential where you are trying to create a completely immersive experience.


3) Auto Stereo:

This is stereoscopic visualisation without glasses, and is where a lot of development is currently happening. All of the major LCD screen manufacturers have screens either available now or in development. There are some that are almost affordable (£1,000 -£1,500) but screen sizes are usually below 19" and others tend to be expensive... but of course with time this will change and as gamers start to buy the screens...


Great for individual use and in situations like libraries, but are not yet a replacement for large scale visualisation and the benefits that it can bring.



Hardware Links :




Beware of acrylic or film type filters these don't tend to last and can be affected by heat from the lamp either melting or depolarising.... Glass filters tend to last longer. Also think how you are going mount and adjust the filters, this makes the difference between good stereo effect and headaches due to loads of ghosting. For this reason we have tended to use round filters that can be rotated to obtain the best exclussion.


American Paper Optics :

Have a range of both acrylic and glass filters and up to fairly large sizes to order. I don't think they are listed on their web site ... but ask for Craig Jones :-)

direct telephone:     +1-303-399-8889

direct fax:               +1-303-399-8881

website:          www.3dglassesonline.com

or email him at :  CraigJonesAPO  at  comcast.net   but first removing spaces and replacing the at with the @ symbol.  


Cokin :

Cokin A series Linear Polarised :


We use these on our NEC LT265 and LT245 based travelling systems along with our SilverFabric demountable screens. However they are not great with our DaLite screen and for this we use our Christie (B+W) Filters.


List of online stores



SilverFabric :

They offer a range of filters and specific filters for use with both DLP and LCD projectors.



Screen Tech Filters :





Lee Filters :

The Lee filter system is not cheap, but it is very flexible and by using the right combination of holders and filters it can make your life just a little easier. Do watch though, we have found that they are very heat sensitive and need to be mounted further from the lens than other glass filters we have used.





B+W Filters :

Again not cheap, but we have found the B+W filters do give good exclusion (less ghosting) with some of the cheaper screen materials.








American Paper Optics are still the best source for both paper and robust plastic theme park style glasses. They also do more expensive Aviator glasses which are to be recommended for prolonged use.











Where you want to shorten the distance from screen to projector you can introduce a front silvered mirror in the light path. Often used with rear projection systems.




Projector Mounts


Chief - Stackers






Use the LCD2c for ceiling mounting along with the appropriate projector RPA and the LSB100.


Use the LCD2TS for ceiling mounting along with the appropriate projector RPA and the LSB100.


LSB100™ Lateral Shift for LCD/DLP Projector Mounts



If using the Chief stacker the Nav1 and Nav2 mounts are worth looking at as a method of mounting 105mm filters... you may need to modify by extending the arms to move the filters further away from lens.





The ASU Slide Stacker is great for smaller projectors and portable systems.... we have used the single shelf version. placing one projector on bottom and one on the adjustable shelf. You will need to adapt to suit your projectors and to fit the filters. However these have now  been discontinued, but still may be available by some web searching.



Premier Mounts - Dual Mount for Ceiling Installation




This is now being discontinued in the UK... may be available from USA or perhaps by special order?




BenQ :

MP830/831 - with 2D Keystone looks like it could be a good choice. Not been tested.



MP771 - 3000lms. This has a fixed ratio short throw lens (no zoom) and can fill a 2.4m wide screen from around 1.6m. We have recently tested these. The short throw lens is amazing, creating very little discernible distortion. We did find that there was some difference in the optics in both projectors, projecting at a different angle and creating a different size of image from same distance. This worked to our favour... but may not always be the case, so would be wise to ensure that you can return the projectors till you get a set up that works. 




Two MP771 on the now discontinued Chief ASU stacker. You do need

to remove the support bar under the first shelf to enable the bottom

projector to fit.






Christie have been doing stereo for ever :-) and always have a good offering, so worth checking out. But can be pricey...



Evans & Sutherland

Laser Projection


Laser projectors have been the holy grail of projection for sometime... but very specialist and very expensive! As with most technologies, increased use leads to dropping costs, until finally, they become mainstream. This new projector from E & S probably marks the very beginning of this process.





Just look at the resolution 8192 x 4096 Mono or 4096 x 4096 Stereo, and the optics options and the nanopixel stuff :-)


I want one.... costs, don't ask.  But others are sure to follow :-)








XD2000u & WD2000u - A competitively priced DLP with lens shift and a short throw lens adapter is available. The lens shift is limited and have seen mixed reviews of colour rendering.... but still looks like it could be worth considering. Not been tested.




Above : The sadly discontinued LT265 with 3D reform... probably the simplest passive stereo system to set up quickly, and is what we still use for our 3D school shows.



3D reform is a great feature, but NEC have dropped it from all but the largest of their DLP's which is a real shame... Our favourite projectors are still our LT 245's and LT260's. You can use NEC's LCD's which still have 3D Reform, but will need to use filters from someone like SilverFabric that can be used with LCD's which already have polarised the light path (http://www.silverfabric.com/html/sf_polarizers.htm).


DLP's to consider NP50 or NP60 or if money and size no problem then NP4000/4001


If you want 3D reform then the LT380 LCD is your only option and if lens shift will do then the NP1150 LCD's might do the job... but remember those special filters for LCD from SilverFabric.




Optoma offer a wide range of basic DLP's and I know there are many users... but watch out for venting arrangements and check that it is ok to stack them.




PT D3500E a hulking beast of projector, but designed for 24/7 use and easy to maintain - worth considering.... Now seems to have been discontinued.

The PT D4000 is similar, but watch how you stack! There are minimum distances bewteen projectors to allow for heat dispersal... and not following these could mean your warranty is revoked. Check with your supplier before buying. These have now been discontinued.



Projection Design :

Great projectors, but can be a little pricey... around £3k for the Evo and £6k for the F20, but you get what you pay for..



Projection designs entry level projector, does have vertical lens shift, but position of the manual lens shift adjustment is not great when stacking (it is on the top). It is 2,500lms and a 1400 x 1050 resolution which is it's big plus. For entry level installs this is the projector to aim for unless you can stretch to the F20sx+ below :-)




F20 sx+

Another great projector from Projection Design, there are a number of options on lenses and colour wheels, 10 bit and 24/7 operation make this really hard to beat unless you need more power and then the F3 is probably what you are looking for .





The ultimate option....







Sharp XG-PH70X - 5200 ANSI - XGA DLP projector


Sharp XG-PH50X - 4000 ANSI - XGA DLP projector


These have lens shift and Digital Keystone which seems to be similar to NEC's 3D reform but never been tested.


Screen Surfaces

Having used a number of surfaces I would suggest Silverfabric




It is robust, high gain and has great exclusion ... it can appear a little grainy if sitting too close with white images.... but a great screen... and allows use of low lumens projectors. We currently use our LT 260's in eco mode (so around 1900lms) to fill a 240cm x 180cm screen ... on full they are too bright.


Other Surfaces


Harkness hall

Harkness Hall Spectral 240 3D

This is a soft surface and easily damaged, but does give good results. It is a neutral screen so will require brighter projectors than the SilverFabric. The Harkness Hall fast fold system can be used with this screen.



Harkness Hall RP 3D

This is a rear projection surface. The Harkness Hall fast fold system can be used with this screen.



Da-Lite Silver Matte

Can be purchased in a range of screen formats and types... usually cheap, but we have found that exclusion/ghosting can be a problem with some filters.



Really good screens, but pricey.

Technical and other Links


Polarisation Help



The above information is a statement of personal preference by the writer and the DLF takes no responsibility for the accuracy of the information or the views expressed.