So far we’ve talked a ton about choosing a screen, but we haven’t actually talked anything about the actual screen at all! This has all been training, young grasshopper. I feel you are now ready to snatch this pebble from my hand, and we’ve finally arrived at what is without question the most important decision you will make when selecting your screen: the material.
When choosing the proper material for your projector, the two principal things you’ll want to keep in mind are color and gain. Additionally you might also need to consider acoustic transparency and rear projection options and maybe something special for your 3D needs. Let’s discuss…
When you think “projection screen” you probably think of a white screen, and that’s true for the vast majority of screens. However, screens also come in shades of grey/silver and even black. Yes. Black. For a projection screen. Why would you ever select a screen color other than white? Because your room is too bright.
If your room has a ton of light, like say a living room without window treatments then you should seriously consider Screen Innovations’ Black Diamond.
If you have a perfectly dark room – or significant control over the amount of ambient lighting – then go with a white screen. It will offer the most options from every manufacturer and will produce the most uniform, reference looking image and deliver the most from your projector. Every projector reviewer I know uses a white screen, so if your room allows it, white-is-right.
However, if you like to watch with the lights on or you want to put a projector in a room that can’t be made dark then white might not be right. A white screen is easily washed out with even a little light in the room, causing blacks to disappear. Fortunately, screen materials like Stewart Filmscreen’s Firehawk or Draper’s XS850E have a silver color to them and are designed to reject ambient lighting and deliver a great image while the lights are still on.
If your room has a ton of light – say a living room with no window treatments – then you should seriously consider Screen Innovations’ Black Diamond. This screen is totally black in color, but produces amazing images even in a fully lit room. (There can be no lights 90-degrees to the screen.) Additionally, since the Black Diamond is black, with the lights out you can’t see the screen so you don’t need to invest in a masking system. Bonus.
All screens have a “gain” and since bigger is always better, you want to get the screen with the highest gain possible, right? Like a gain of 10 or something would be at least ten times – possibly even exponentially better – than a 1.0 gain screen, right?! Wrong.
Gain refers to the amount of light the screen reflects compared to a reference, uniform reflecting surface called a Lambertian surface. Whereas the perfect Lambertian surface scatters light evenly in all directions – not a good thing for projection as this will actually wash out the image – a screen is designed to focus light back towards the viewer.
In a light-controlled room – ie: dark – a lower gain will produce a better picture
The problem with adding gain is that it can create hotspotting, where the center of the image is noticeably brighter than the sides. It also cuts down on your off-angle viewing, where the image will be much dimmer off to the sides. This may not a problem if everyone – or at least you – are sitting directly in front of the screen, but could be an issue if you have a wide room with people sitting all over the place.
In a light-controlled room – ie: dark – a lower gain will produce a better picture, and the screens that are generally considered to be “reference standard” – like the ones that they master the movies on in Hollywood and that highfalutin equipment reviewers use – have a gain of somewhere between 1.0 and 1.3. If you have a narrow room, or are trying to drive a large screen with a low-lumen projector, then you can increase gain as needed. To quote video reviewer extraordinaire, Geoff Morrison, “I don’t recommend ultra-high-gain screens, at least not for most people. Most projectors these days are plenty bright, and I prefer a smooth, uniform image over a few extra footlamberts.” If you think you know more than Geoff, then proceed accordingly.
You might stumble across screens with a gain of less than one, like .8. These are called “negative gain” screens, actually reflecting less light than the projector outputs. In the early days of digital projection, when projectors couldn’t really produce a really deep, inky-dark black, these grey, negative gain screen helped to make a darker image and bumped up contrast ratio. However, modern projectors can produce a quality black level and I think the “benefits” of the negative gain screen are outweighed by the lower light output.
Know where the speakers are in a commercial theater? Take a drink if you said behind the screen. (Take two drinks if you didn’t.) If you ever get up close to a commercial movie screen you’ll likely notice many little tiny holes in the screen called perforations, or perfs. These perfs allow the sound to pass through the screen to your precious little movie-listening ears. If you want to recreate this experience at home, then you’ll need what is called an acoustically transparent screen. The potential drawback with perf screens at home is that since you are sitting closer to the screen, you are more likely to notice all of the little holes. Also, because there are a bunch of little holes that let light shine through, you lose a bit of light output from your projector. Finally, with some perf screens, you can get a moire pattern with the pixel structure of your DLP or LCD projector, not a good thing. Another option is a woven screen. This is a fabric similar to a speaker grille cloth that doesn’t have any holes or introduce moire while still letting sound pass through. However, you might notice texture in a woven screen depending on how close you sit. No material is 100% perfectly transparent to sound, so you might need to either bump the volume or use some equalization to account for the screen’s effect on the sound.
Virtually any projector can be used in a rear projection application, where the projector is behind the screen. With the projector housed in a completely darkened room, you can enjoy a terrific image no matter what the lighting condition is in the room. You also don’t have to worry about any projector fan noise, have to endure that one jack-ass that always thinks he’s being cute by making shadow puppets on the screen – “Look! The Godfather has rabbit ears! Aren’t I hysterical?!” – or even have to see the projector. There are a lot of installation issues when going with a rear-pro install, but when done right, it can be crazy awesome. One of the best materials I know for a rear-pro application is Stewart Filmscreen’s StarGlas. You’re definitely into custom install territory here, so talk to your installer about different options.
If you just have a regular projector that does 3D – as in you have only one projector, not two – you won’t need to have a special screen to enjoy 3D. However, if you are lucky enough to have a dual-projection system for 3D – a separate projector for both left eye and right eye like Runco’s d-73D – then you will need a special material that retains the polarization needed to achieve the 3D effect. In this case, you’ll need a polarization preservation screen like a Mocomtech, Stewart Silver 5D or Elite Screens AirBright 3D2. These also generally have very high gain to deliver a crazy bright image to counteract the much lower light output of a 3D presentation.
To deliver the best compromise between 2D and 3D viewing, some companies have created screen materials they are calling 5D – 2D + 3D = 5D, get it? – to offer the best of both worlds. Elite Screens offers the AirBright 5D and Stewart has the Silver 5D, and if you watching a lot of 2D and 3D material on your dual-projection system, these might be the perfect solution.
Phew. That’s it. That’s all I got. If there is still a question you have on projection screens, feel free to ask it in the comments. Otherwise, it’s time to stop reading and start watching!