Guide to Front Projector Screen Surfaces
Surely, there is a vast selection of projection screen fabrics
and projection surfaces but...
There is no MAGIC projection screen surface that performs well under all conditions. In other words, paying attention to the type of video projection surface you choose is an important aspect in every projector screen purchase.
Unfortunately, for many in the market for a projection screen, the large selection of projection screen surfaces can turn out to be confusing - even frustrating. This needs no longer be the case. Follow the criteria detailed in this guide to identify an optimum surface for your video projection application.
Projection Surfaces and Fabrics
Projection screen manufacturers have come up with a wide range of projection screen arrays in an equally vast choice of projection surfaces to suit different presentation media. This in itself is a guarantee that there is always a projection screen solution irrespective of your needs and application constraints.
However, many fail to realize that there isn't an all purpose projector screen surface that performs efficiently under all home theater conditions. Unless you are well informed, you may easily end up going for the wrong projection screen choice, in particular when it comes to choosing the right projection surface for your application. This projector screen fabric selection guide focuses on a specific media application, namely that of home theater and home entertainment.
More often than not, these selection criteria that come into play are related to your projection setup constraints within your projection environment. Ambient light conditions, projector placement, projected image brightness, image resolution, room configuration, budget constraints, etc., all play an important role in deciding which projector screen surface to use.
An equally important factor often ignored is screen maintenance. Selecting a 'perfect' projection surface that is difficult to maintain for use in a dusty environment is far from ideal.
This projection screen selection guide discusses the basic selection criteria one has to take into consideration to identify the right projection screen surface in a front projection setup. However, prior to discussing these criteria, we present a few 'movie screen basics' as the same operational principles apply in the home theater. This should help you get a better understanding of the requirements associated with the projection screen.
Article continues after this advertisement.
It is a fact that at first glance, movie screens look incredibly simple - a big stretched sheet of white fabric. But a deeper inspection would soon reveal that there is a fair amount of technology and design involved in their creation.
Movie projection screens are made from heavy white vinyl but using different screen surfaces depending on the application. Movie screen surfaces are categorized according to the amount of light they reflect.
There are four main categories of screen surfaces:
Matte white: This represents a surface with less than 5% reflectivity; black is very dark gray to black but the image is not very bright.
Pearlescent: Surface reflectivity is typically 15%; black is dark gray and image is bright, provides best overall contrast.
Silver: 30% reflectivity; black is medium gray and image is very bright, dark colors may seem a little dull.
Glass bead: This represents the surface with the highest level of reflectivity - typically 40%; black appears as light gray and image is usually too bright. Normally, this type of projector screen surface is used only under special conditions.
Pearlescent is probably the most common choice for a typical movie theater. To make a pearlescent or silver screen, a reflective coating is added to the matte white vinyl.
A glass bead screen uses thousands of tiny glass marbles embedded in a transparent coating on the surface of the screen.
Yet surface reflectivity is just one aspect of a movie theater projection screen. As further detailed in the first part of this series of home theater screen selection guides, movie screens are designed not only to present a great picture but also to support the theater sound system. For this reason, most movie screens have tiny perforations in them to render the screen acoustically transparent. In this manner, the audience will be able to hear speakers placed behind the screen for a more enhanced sound field.
In a typical movie theater application, you will find three speakers behind the screen, located at the far left, center and far right. In the home theater, usually it is only the center speaker that is positioned behind the projector screen - but this mainly depends on the overall projector screen width.
Placing the speakers behind the screen leads to a more realistic sound experience, particularly with the movie dialog. It also leads to an overall surround sound field that better encompasses both the projected movie image and the audience.
There are a number of basic considerations you have to consider to arrive at the right projector screen surface. Projection method, ambient light, display brightness, seating layout, projector placement, and image detail are all important issues to consider when selecting a projector screen.
Equally important is the projection screen maintenance; this is something many fail to think about at the time of purchase but regular projection screen maintenance is important to ensure that your projector screen continues to deliver the very best images years down the line.
Understanding how these issues impact image performance is essential prior to choosing a projector screen surface. Many would argue that most major projection screen manufacturers' websites include easy-to-fill checklists which once completed, would automatically present you with their recommended screen fabric for your application.
This is true and to a certain extent, these checklists and screen calculators render the selecting a projection screen a straight forward one. Yet we still say that having a proper understanding of the basic projector screen selection criteria is the only way to ensure you make the right choice.
Projection Screen Surface - Selection Criteria
1: Projector Type
The type of projector screen surface to use is partially dependent on the projection technology of your video projector. Common technologies in the home theater area include 3-LCD, single and three-chip DLP, and LCoS; most of these video projectors use a metal halide bulb as their light source though a few make use of an LED bulb.
Each of these technologies handles brightness, contrast and color intensity in a different manner. Hence projection screen manufacturers have developed specially formulated color corrected screen surfaces that best complement these different imaging technologies.
2: Ambient Light
Any projected image is at its best when viewed in total darkness, this being so independent of the projector brightness output. However we live in an imperfect world where not everything is under our full control.
Obviously, the first step is to minimize ambient light during a movie, in particular, avoid any stray light falling direct onto the projector screen as this causes the projected image to washout. However, selecting a suitable high contrast projection screen surface can still help you enjoy an image with a sufficient contrast even under moderate ambient light levels.
3: Projected Image Brightness
The brightness output level of your projector is a measure of the projector output power in terms of light intensity. Yet, it is important to realize that the end projected image brightness―or image luminance―is a different issue as brightness falls in proportion to the area of the projected image size.
This means that the bigger your projected image is, the dimmer it will look for a fixed level of projector brightness. At the same time, it is extremely important that you do not end up with a too bright an image that would be uncomfortable on the eyes of the viewers. This necessitates the need to match the screen gain with the projector output level, screen size and ambient light. This also means that one cannot proceed with a projection screen purchase in isolation from your video projector.
We discuss this subject in more detail in the third part in this series of projection screen guides.
4: Room Layout
The Society of Motion Pictures and Television Engineers (SMPTE) recommends that for the best viewing experience, the ideal screen size for home theater use should occupy a 30-degree field of view in the horizontal plan at the seating position. This in itself limits the seating area in your home theater room. This 30 degrees field of view is necessary for a person to feel immersed into the movie action.
Some projection screen companies recommend limiting the seating area to approximately 30 degrees from either side to the center of the projector screen; this in effect makes for a 60-degree field of view. This may seem in contradiction to the SMPTE recommendation. But this 60-degree represents the limit beyond which sitting at the extreme sides of the projector screen would be too uncomfortable for normal viewing; it does not represent the ideal seating in the home theater.
Irrespective of the above viewing angles, if your home theater room configuration calls for a wider viewing angle, make sure you use suitable projector screen surface that can maintain adequate image brightness even at extreme viewing angles. This is important as all projection surfaces have a defined angle of view beyond which the projected image would lose its brightness at a rate that is dependent on the projection surface itself.
However, no matter how wide is your room, never loose perspective of the 30-degree SMPTE recommendation for an immersive experience, and even more so, the 60-degree limitation for comfortable viewing.
For more information on viewing distance and home theater seating, please refer to the following guides appearing on our site:
TV Viewing Distance: Discussing viewing distance versus screen size
Home Theater Seating: Guide to correct seating layout
5: Projector Placement
Projector placement with respect to the projection screen is another important factor to consider when selecting a projection screen surface. The issue mainly arises when making use of a high-gain projection screen; placing your video projector on a floor-stand would require a different type of screen surface than when the projector is ceiling mounted. Why?
Image: Courtesy 'Da-Lite Education'
If the projector and the audience are on opposite sides of the normal to the screen (ceiling mounted version), use should be made of a high gain screen with an angular reflective surface; these reflect light at the same angle it hits the screen surface.
When the projector is positioned on the same side of the normal to the screen center as the audience, i.e. the floor mounted version, use should be made of a high gain screen with a retro-reflective surface.
6: Projected Image Detail
This is all a matter of whether you are displaying standard or high definition content.
Screen surface is not much of an issue with standard definition video. But to fully enjoy the fine image detail supported by today's 1080p high definition video projectors especially at close viewing distances, you need to use a screen with an exceptionally smooth surface.
7: Screen Maintenance
Hardly considered during a projector screen purchase, yet to get the best performance, the screen surface should be kept clean all the time.
While in general this is not a problem especially in the dedicated home theater room, there are situations where the screen surface may be subject to a higher level of airborne debris and dust that may settle on the surface. However, more problematic is the case where the screen surface may be subject to potential soiling or even damage from constant handling.
Under such circumstances, an easy to clean screen surface is a pre-requisite for continued best performance over time.
Buying options for
Home Theater Projection Screens
amazon.com offers a vast choice of projection screens from major suppliers - often at reduced pricing.
While at amazon, check the customer feedback for a better insight about the product and customer experience.