Projectors and projections have become an important part of modern technological life. Whether you’re a student, a moviegoer, a businessman, or something else, you’ll probably find yourself in a situation where you need a projector, a projector screen, and a projection. While you probably know the essential elements of making a presentation and setting up a projector, you probably don’t know all the technical details of configuring your projector screen. In this article, we are going to tell you all those aspects so you know how to choose and set up your projector screen for the best possible experience.
There is no best material for the projector screen. It depends on what are your needs, how much space do you have, the location where you want to put the screen, etc.
Below, we will represent you all the material that can be used for the projector screen, and what you have to look in when buying a one.
What Is a Projection Screen?
A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed, as it is in cinemas; painted on the wall; or portable, with tripod or floor rising models as in a conference room, a classroom, or some other non-specific viewing space. Another popular type of portable screen is inflatable screens for outdoor movie screening (open-air cinema).
Uniformly white or grey screens are used almost exclusively to avoid any discoloration to the image, while the most desired brightness of the screen depends on a number of variables, such as the ambient light level and the luminous power of the source of the image.
Flat or curved screens may be used depending on the optics used to project the image and the desired geometrical accuracy of the image production, flat screens being the more common of the two. Screens can be further designed for front or back projection, the more common being front projection systems, which have the image source situated on the same side of the screen as the audience.
Different markets exist for screens targeted for use with digital projectors, movie projectors, overhead projectors, and slide projectors, although the basic idea for each of them is very much the same: front projection screens work on diffusely reflecting the light projected on to them, whereas back-projection screens work by diffusely transmitting the light through them.
What Material Are Projection Screens Made of?
The answer to this question depends a lot on the type of screen used. This means that each specific type of projection screen has its own structure and they are, despite being the same specific object, not the same.
In most commercial movie theatres, the screen is a reflective surface that may be either aluminized (for high contrast in moderate ambient light) or a white surface with small glass beads (for high brilliance under dark conditions). The screen also has hundreds of small, evenly spaced holes to allow air to and from the speakers and subwoofer, which often are directly behind it. This is a very specific construction that gives the viewer a better viewing experience, as the image (film) is clearer, brighter, and more detailed.
Pull-down screens (also known as manual wall screens), the most common types of screens used in schools and other non-specific spaces, are often used in spaces where a permanently installed screen would require too much space. These commonly use painted fabric that is rolled in the screen case when not used, making them less obtrusive when the screen is not in use.
A similar type of screen is electric screens that can be wall-mounted, ceiling-mounted, or ceiling recessed. These are often larger screens, though electric screens are available for home theatre use as well. Electric screens are similar to pull-down screens, but instead of the screen being pulled down manually, an electric motor raises and lowers the screen.
Electric screens are usually raised or lowered using either remote control or wall-mounted switch, although some projectors are equipped with an interface that connects to the screen and automatically lowers the screen when the projector is switched on and raises it when the projector is switched off.
Switchable projection screens can be switched between opaque and clear. In the opaque state, the projected image on the screen can be viewed from both sides. It is very good for advertising on store windows. A similar concept is used in mobile screens usually uses either a pull-down screen on a free stand, or pull up from a weighted base. These can be used when it is impossible or impractical to mount the screen to a wall or a ceiling.
Both mobile and permanently installed pull-down screens may be of tensioned or not tensioned variety. Tensioned models attempt to keep the fabric flat and immobile, whereas the not tensioned models have the fabric of the screen hanging freely from their support structures. In the latter screens, the fabric can rarely stay immobile if there are currents of air in the room, giving imperfections to the projected image.
A very specific type of screen is the already-mentioned inflatable screen. The projection frame of an inflatable screen is made from PVC coated fabric layers joined by high-frequency welding or mechanical sewing.
The projection surface can be made of PVC or spandex, with the latter providing for rear projection capabilities. The projection surface can be detachable for ease of care. The frame is inflated with a high-pressure air blower. Larger frames may require a three-phase blower.
For bigger screens, the blower typically continues to operate, ensuring the screen remains fully inflated. For the consumer market and smaller screen sizes, the screen is sealed and does not require a constantly operating air blower.
When talking about screen materials, a very important question is the gain of a projection screen. It is a very specific measure usually quoted by screen manufacturers when talking about the specifications of a projection screen. What is a gain?
A gain is actually a number, the measure of the reflectivity of light of a screen, that is typically measured as the peak gain at zero degrees viewing axis, and represents the gain value for a viewer seated along a line perpendicular to the screen’s viewing surface. The gain value represents the ratio of brightness of the screen relative to a set standard (in this case, a sheet of magnesium carbonate).
Screens with a higher brightness than this standard are rated with a gain higher than 1.0, while screens with lower brightness are rated from 0.0 to 1.0. Since a projection screen is designed to scatter the impinging light back to the viewers, the scattering can either be highly diffuse or highly concentrated.
Highly concentrated scatter results in a higher screen gain (a brighter image) at the cost of a more limited viewing angle (as measured by the half-gain viewing angle), whereas highly diffuse scattering results in lower screen gain (a dimmer image) with the benefit of a wider viewing angle.
The number is compared with screens coated with magnesium carbonate, titanium dioxide, or barium sulphate when the measurement is taken for light targeted and reflected perpendicular to the screen. Titanium dioxide is a bright white color, but greater gains can be accomplished with materials that reflect more of the light parallel to the projection axis and less off-axis.
What Color Screen Is Best for Projector?
As far as the colour is concerned, projection screens usually come in black or white colours, with grey being a rare example of other colourations.
White screens are the standard, whether you prefer it like that or not. They’ve been around for a while and most people use them; they are also relatively cheap. White is a good choice because it reflects the light very well and also doesn’t alter the coloration of the original image, which means that the screen won’t influence the original.
But white screens also have some issues. They reflect light off the screen onto any nearby walls or ceilings. This reflection of light means you need a very powerful lamp to get a clear, bright image unless you darken the room completely like a movie theatre. It’s hard to get a high-contrast image, too.
True, deep blacks are difficult to produce with a projector as it is, and the white screen compounds those problems. Some of these issues can be addressed and solved with a better projector, but such gizmos usually cost more.
The second option you can pick is a black screen, although they are less common and cost substantially more. Namely, a black screen is significantly better at reproducing the darker portions of an image. This visibly improves the contrast of the image and allows for a better viewing experience.
Black screens also don’t reflect as much light as white screens and perform better in rooms with ambient lighting. Bright colors will also look a little better on a darker screen, which may sound odd to you. As said, this might seem counter-intuitive and illogical at first, but it again has to do with contrast. It’s like writing with yellow or beige chalk – the result would be better observed on a dark background than on a light one. The same concept makes bright colors more visible from a black screen.
A third variant is a grey screen, which is the least common of the three and also cost a lot more when compared to your standard white screen. Gray screens are also called “high contrast screens” because they have similar effects on the projector image like black screens, but somewhat better. The black levels and contrast ratio of a grey screen will be better than a white screen, but not quite as good as a black screen.
This is why they’re often recommended to people trying to make the most of a projector with low lumens. The main issue with a grey screen that it gives every image a greyish reflection, which might be a problem while watching.
As for the answer to our main question – which one is better? – it depends on your intention and the space used. A black screen will give you a sharper image with better black levels than a white screen, especially in rooms with a lot of ambient light. If you plan to use a projector as a replacement for your living room television, a black screen could be a great solution, but be prepared to spend more as black projectors usually cost substantially more than white ones, which is why they are not so commonly used.
What Is the Best Material for Rear/Front Projector Screen?
We’ve already said that there are specific screens for front and rear projecting. This means that you’ll have to pick a specific screen for yourself in order to achieve a better result. So, depending on what kind of projection you want to have (since all projectors can be used for both types of projections, front, and rear), you are going to have to pick a screen.
Although the difference isn’t that big, these two types of projections require different types of screens and we are going to tell you which one you’ll need for which type of projection.
As said, the material that the projection screen is made from is different for front and rear projections. A front projection screen is normally a matt white material and they are quite often designed with a firmer backing that does not allow light to go through it.
This is very useful if you have to place your screen in front of another light source (a window, for example), because the light won’t be able to penetrate the screen, thus disturbing the image. Rear projection screens are made from a semi-translucent fabric and they are normally grey in appearance.
And with this, we have reached the end of our little analysis of projection screens. We have shown you the basics and answered some burning questions and we hope that you have found our little article useful and helpful.
To conclude, you’ll probably be using a white screen when you need it, but there are some possibly better, albeit more expensive, variants – like black or grey – that might also be of use to you. For more information, keep following us and stay tuned for more of the same.