For best results, you should always use a projector on a good projection surface. A flat, white wall is a great first step, but a projection screen produces better results. Especially now that Ultra Short Throw projectors are becoming more popular, the correct choice of the projection screen surface and the setup is of great importance. This article explains everything you should know about Projection screens for projector or beamer.
The importance of a Projection screens for projector or beamer
The surface on which you project has a significant influence on the image. In the first place you naturally want a color-neutral surface. You want a perfectly flat surface for the new generations of Ultra Short Throw projectors. And to get the most out of your 4K projector, the projection surface should not be too rough. If you look at a lot of ambient light, you should also consider an ALR screen (Ambient Light Rejection). A black or dark frame around the image gives a slightly better contrast perception, and it absorbs stray light from the projector that would otherwise be visible around the image. The latter is not equally important for every projector, but it occurs enough to take it into account.
The simplest solution?
There are, of course, a number of simple and inexpensive solutions. You can project on a colored wall. But depending on how far that color deviates from neutral white, that will naturally tint the image. This is visible, but not dramatic if you have a cream white (RAL9001) wall, but even on an ivory white (RAL 1014) wall the effect will be quite strong anyway, let alone on real colored walls.
The above image (by Anna Shvets through Pexels) is a simulation, but it gives a good impression of the effect. Some projectors can compensate the image for this, but that is always only an approximation. If you want a real cinema image, that is not an option.
You can get started with special projection screen paint, provided the wall is smooth and smooth enough. If that is not the case, then you actually have to do plaster work first. If it concerns some minor imperfections, you can still do that, but once you have to make major corrections, it quickly becomes impractical, unless you are a seasoned do-it-yourselfer.
The best and most flexible solution is a projection screen. You have an extensive choice of setups and types of fabric. So there is always a solution that is ideal for your setup.
A fixed Projection screens for projector?
If you have a room that only serves as a home theater or if the presence of the screen does not disturb you, you can opt for a fixed frame. Such a frame is often only a few cm deep, so that it partially disappears into the interior.
If desired, you can even choose a version without a black frame. The canvas then wraps around the frame for a perfect finish. The screen will disappear even more into your interior, but projector placement is very important. After all, you no longer have a black border that hides small placement errors.
Or just a rollable?
If you prefer to hide the screen when you are not watching a movie, then choose a roll-up screen. But even then you still have a lot of different options. Do you hang the screen on the wall? Or on the ceiling? Or do you want to build the screen into your ceiling? With some manufacturers you can even choose the color of the housing.
All these variants are often also available in a motorized version. The screen can be rolled out with a switch or with a remote control. If your projector has a 12 V trigger output, it can control the screen. As soon as you switch on the projector, the screen will automatically roll out.
In addition, you must also take into account the requirements of your projector. Ultra Short Throw projectors absolutely need a perfectly flat surface because even the slightest bump or wrinkle translates into obvious image defects. If you want a roll-up screen, it is best to choose a tab-tensioned screen. A cable then runs through the small tabs on the parabolic side of the screen. Together with the weight of the bottom bar, this keeps the screen stretched nicely.
Choosing a screen cloth: the right ‘screen gain’
Screen cloth is available in countless variants to use as Projection screens for projector. Several factors determine the ideal choice, but one of the most important factors is the screen gain. Each type of screen has its own ‘screen gain’, a factor that determines how much light the screen reflects back to the viewers.
- Neutral white screen cloth has a gain of 1.0.
- Screens with a gain lower than 1.0 absorb part of the projector light and thus improve the black display and therefore the contrast perception. Such screens are light to dark gray (depending on how low the gain is). They also help with limited ambient light as the dark screen absorbs not only projector light but also ambient light.
- Screens with a gain higher than 1.0 reflect more light to the viewers. That is of course excellent if your projector does not generate a lot of light. Of course, a screen cannot produce light itself. A high gain screen works because it focuses the incident projector light towards the viewer. Such a screen often has a slightly smaller viewing angle (depending on how high the gain is, of course).
When choosing your fabric, take the following factors into account:
- High gain screens improve the light output, they are ideal for the business environment where you mainly have to overcome the ambient light and contrast is less important. But if you mainly watch sports, it might also be a good choice at home.
- Low gain screens improve the black level and somewhat the contrast. They are a good choice when you can partially darken and your projector provides enough light.
- Keep in mind that the horizontal viewing angle often depends on the gain. Lower gains have a wide viewing angle, higher gains a narrower viewing angle.
- Neutral screens are a good, safe choice. By choosing a slightly higher gain (1.1) or lower gain (0.9) you can still set certain accents.
However, these are just guidelines. You have to look for the properties of different screen materials in the specifications. To be sure that you make the right choice, it is best to be guided by a product specialist.
Other screen cloth properties
Screen gain is not the only determining factor for the screen fabric. There are also other things you can or should pay attention to.
- Structure: Now that we also project in 4K, your canvas should not be too rough. A quick calculation shows that a pixel of a 4K image on a 100 inch screen is a maximum of 0.58 mm wide. If the structure of your screen fabric is too rough, the finest detail may become more difficult to see. If you want to project 4K, choose a canvas that is suitable for that, such as Projecta HD Progressive.
- Acoustically transparent cloth. Do you want to put the front speakers out of sight, behind the screen cloth? Then you should choose this type of cloth, the small perforations let the sound through.
- Ultra Short Throw: because UST projectors send their light to the screen at a very extreme angle, you also have to check whether the fabric type you want is suitable for UST projection.
Ambient Light Rejection (ALR)
For better Projection screens for projector, we also want the advantage of a large projection screen in the living room. But the living room is of course not a dark cinema room, and darkening is not always possible, especially during the day. In such a case, an ALR screen can be the solution. These screens reflect the incident light from the projector, but use a fine saw-tooth structure to block the light from the top of the screen.
The impact of an ALR screen is great, something we could easily see during our visit. The difference in darkening is not visible, but as soon as you switch on the lights, it immediately becomes clear which of the two screens is ALR. Also keep in mind that an ALR cloth for a long throw projector is different than for Ultra Short Throw projector.
How big do I want my screen for Projection screens for projector?
You choose the size of your screen according to three factors:
- The viewing distance
- The light output of the projector
- Or you can darken or not
You get a projector because you want a big picture. We therefore assume that you are aiming for at least 80 inch screen diagonal (1.78 m wide, 1 m high), and preferably even 100 inches (2.2 m wide, 1.25 m high). That is substantially larger than an average television. The reason is simple, for a real cinema experience, the image must fill a large part of your field of vision. In addition, there are also guidelines from THX and SMPTE that state that the image must fill at least 36 ° (THX) and 30 ° (SMPTE) of your field of view. In concrete terms, this means the following:
- Minimum screen diagonal (in cm) = viewing distance (in cm) divided by 1.6 (for 30 ° field of view)
- Maximum screen diagonal (in cm) = viewing distance (in cm) divided by 1.2. (for 40 ° field of view)
- We often use the ideal size as the ideal size: screen width (in cm) = viewing distance (in cm) divided by 1.5. That equates to approximately 37 ° field of view.
In addition, the light output of your projector and the viewing conditions also determine how large your screen may be. After all, the light output of the projector is spread over the entire screen. The bigger the screen, the dimmer the picture. And of course you have to take into account the ambient light with which the projector has to compete. There are also guidelines from THX and SMPTE for this. When completely darkened, the bar for screen brightness (white) is 16 fL (55 cd / m²). With moderate ambient light you should aim better at 32 fL (110 cd / m2) and with a lot of ambient light at 48 fL (165 cd / m2). In the table below, you will find the screen size (diagonal in inches) to the right, followed by three columns of the projector’s required lumen output for these three viewing conditions.
|Screen diagonal (inch)||In case of darkening (Lumen)||In moderate ambient light (Lumen)||With a lot of ambient light (Lumen)|
These figures assume a screen with gain 1. If your screen has a lower or higher gain, divide the number from the table by your screen gain to find the required lumen output of your projector.
Tips for assembly and use
- Keep in mind that a screen really has to be level. If your screen is slightly skewed, it can cause wrinkles. How quickly that is visible depends of course from model to model. If possible, use a cross line laser.
- Since a screen is easily two meters wide, hanging it up is a bit more difficult than an average TV mount. It can also weigh a lot, especially the electric versions, so get some help!
- A brand new screen has a fairly clear ‘new smell’. After a few days to a week, that should disappear. Projecta points out that their screens are Greenguard and Greenguard Gold compliant, so this scent is absolutely harmless.
- Clean your screen with a dry clean cloth. If there is real dirt on the cloth, a cleaning agent based on an alcohol solution is available through Legrand. A vinyl projection screen is a delicate product and should be treated with care.