Nothing beats a big picture. It significantly adds to the feeling of being part of the events depicted in the picture.

Even the picture sizes of televisions have grown year by year. I remember how in the early 1990s a 32-inch ”giant” would make even the guys wonder. Nowadays, 32 inches is already the smallest size.

Year by year, the image sizes have grown, and at the same time prices have decreased. At the cheapest, you can get a 65-inch TV for as little as under 800 euros (however, the price range always reaches up to 8,000 euros). Instead, a 75–90-inch screen costs between 10,000 and 30,000 euros, and that no longer makes sense.

The solution for a really large screen is a video projector, In colloquial parlance, it is called a video display. It is a device that projects an image from a source (a TV tuner, digital box, DVD/Blu-ray player, or similar) using a bright light source onto a fabric or other surface that reflects light.

With a video projector, you can easily get a 100–120-inch, or even 300-inch, image for a fraction of the price of a large TV. When the prices of even fairly decent video projectors start at 600 euros, it’s no wonder that their popularity has been on a strong upward trend. A video projector is even a viable alternative to a TV, even though you usually buy a video projector in addition to a TV. A TV for everyday use and a projector for movie, sports, and gaming evenings.

What should be taken into account when choosing, installing, and using a video projector?

Choosing a video projector is a bit more complicated than choosing a television. The differences between projectors are greater than with televisions; you need more space, and a high-quality end result requires a little more than just plugging the projector into a wall socket.

However, there is also some relief coming with the new so-called ultra-short throw projectors, but we’ll get into that in more detail later.

The projector should be chosen primarily based on the conditions and requirements of the space and its intended use, and the characteristics and technical performance of the projector. These include, among other things, the image size, throw ratio, zoom, image transfer, image resolution, projector light output, image contrast ratio, and projection flatness. And the size of the image is determined based on the placement and size of the screen.

LCD or DLP?

Video projectors nowadays mainly use two different technologies to produce the image: LCD or 3LCD (Liquid Crystal Panel) technology based on a liquid crystal panel, and DLP (Digital Light Processing) or micro-mirror technology. And there are even different variations and levels of development among them. For example, the D-ILA developed by JVC and the SXRD by Sony.

Due to the scope of the topic, we will now only briefly discuss LCD and DLP technologies. However, it should be noted that both technologies have their advantages, although there are also different opinions about them: the advantages of LCD are said to be cleaner and, above all, brighter color reproduction, image brightness, sharper image (with reservations on the same resolution), and quieter operation. On the other hand, they feature a more clearly visible pixel grid and weaker contrast especially in large image areas.

In LCD projectors, the light is routed through a red, green, and blue liquid crystal panel. The numerous small ports (2,073,600 in full hd panels) on the liquid crystal panel allow the light to pass through at different intensities, forming the image from these pixels onto the lens, which is projected onto the screen through a magnifying lens.

In DLP projectors, the image is formed using a micro-mirror panel and a so-called color wheel. The color wheel is synchronized with the panel so that red, green, and blue light is reflected onto it at a fast rate. A total of 2,073,600 tiny mirrors reflect the corresponding part of the image in turn, and the image is then projected through a magnifying lens onto the screen. The viewer does not notice the differences in the colors; they perceive the image as a normal color image.

The BenQ W2000 Full HD DLP projector is one of the best-selling models in Finland in its class and has performed well in tests. The W2000 has a so-called Rec.709 color format, which means a pre-calibrated image, so the projector should be ready to use straight out of the box. The projector also has lens shift, which allows for versatile placement. Price range under 1,000 euros.

The Epson TW5600 is a high-quality 3LCD basic projector that is promised to produce images of up to 300 inches (width 762 centimeters). It also features lens shift, trapiche correction, and 1.6x manual zoom, 3D capability, a long-lasting bulb, and an affordable bulb price. The TW5650 model also has wireless networking and Miracast support for phones. Recommended prices are €899 and €999.

Optoma GT1080Darbee is a compact and yet versatile full hd 3d dlp short throw projector. Its high brightness, short throw distance and low response time make it especially suitable for gaming. The projector’s response time is only reported to be 16 milliseconds. The manufacturer promises that the vivid image will also be alive in movie use. From a throw distance of one meter, a projection of up to two meters (about 92 inches) is promised. Price range 1,000 euros.

The advantages of DLP are good contrast and therefore very good black reproduction, the absence of pixel networks even in large image sizes, and the smoothness of the image. The disadvantages are some very rare, sometimes annoying, so-called rainbow effect (in certain situations, the colors appear to rain in a rainbow-like manner) and, with reservations, a lack of brightness and clarity in the reproduction of colors compared to LCD technology. On the other hand, the high contrast and good black reproduction often make the image even more nuanced than with an LCD.

Of course, techniques can always be put in some sort of ranking order; each has its pros and cons. In some situations, the slightly underdog-like dlp technology may still be a better option. The ranking also depends on the settings.

So it's worth comparing, and at least Anyone considering a DLP projector should make sure that this rainbow effect does not interfere with the viewing of themselves and other family members.

Here is a demo video showing how the rainbow effect appears in the photo:

What about LED and laser?

We will also talk about LED and laser projectors. However, this is not about any new revolutionary imaging technology; it is about how the projector’s light is produced. Usually, projectors use conventional gas discharge lamps. In LED projectors, the light source is LEDs, and for the main colors (red, green, and blue), there are separate LEDs. Using partial colors improves the image quality. The power consumption of LEDs is low, they hardly heat up, and they have an extremely long lifespan.

In laser projectors, light is produced by a laser. A laser projector produces a high light output and excellent contrast, but at an expensive price. There are also LED-laser hybrid projectors on the market.

Starting point: the order and the investment

It all starts with the setting, the investment in the screen, and the size. These set certain requirements and features for the projector. The features of the projector should therefore be as suitable as possible for the specific installation. In this context, we come across terms such as throw ratio, zoom, offset, lens shift, and keystone correction.

Where the screen is intended to be placed and how large a picture is desired, where the projector can be placed, what the projected distance from the screen is, what the room dimensions are, whether the projector will be mounted on the ceiling, the back wall, or on some kind of level, whether the installation is fixed and so on.

Next, we will briefly review what the aforementioned terms mean and how they relate to the placement of the projector.

How big a picture?

With a video projector, the image can basically be as large as you want, but it must be in the right proportion for the viewing distance and the characteristics of the projector.. In practice, the recommended size is generally between 100 and 150 inches, although in some cases it can be larger (200–300 inches).

To achieve a cinema-like experience, it is recommended in the industry that the viewing distance is no more than three times the height of the image. Since the size of the image is discussed in this context primarily in terms of its width, we also prefer to use a ratio relative to the width here. With a frame ratio of 16:9, the ratio is 0.59. The recommended width of the image is therefore at least 0.59 times the viewing distance from the image surface, but a wider width is also not a problem. In home conditions, the image can very well be the same width with the viewing distance, and anything that exceeds the television’s image size by quite a bit is kept at home.

The bottom edge of the image is recommended to be positioned at a height of 60–90 centimeters from the floor.

The size of the image produced by a video projector is often referred to as the width of the image in meters or centimeters, whereas with televisions it is referred to as the diagonal, and this refers to the diagonal aspect ratio. If we talk about the diagonal in the case of video projectors, then we usually mean the diagonal of the image area as well.

The size of the image produced by a video projector is often referred to as the width of the image (in meters or centimeters), whereas with televisions the term refers to the diagonal of the image area from corner to corner. If we measure in inches with video projectors, then we usually mean the diagonal of the image area as well.
The image actually grows larger than one might think from the size alone. For example, a 100-inch image is almost 1.8 times larger in area than a 65-inch one, even though the difference in diameter is only 35 inches. The difference is significant. Similarly, a 120-inch image is already 2.6 times larger than a 65-inch one.
The width of the image at 100 inches, with the typical 16:9 aspect ratio, is 221 centimeters and 120 inches with the 16:9 aspect ratio.

The accompanying image gives a good idea of how much larger a 120-inch image is compared to a 48-inch one. The difference is huge! You can even get such a picture for under a thousand euros.

Size and viewing distance

In principle, a 100–120-inch picture is an experience even from normal viewing distances in a room., But to achieve a cinema-like experience, the width of the image should be at least 0.59 times the viewing distance, but it can be much wider than that.

For example, at a viewing distance of 3.5 meters, the width of the image should be a minimum of two meters (3.5 meters x 0.59 = 2.0 meters).

In reverse: The appropriate viewing distance relative to the width of the image is width x 1–1.69. For example, for a 2.7-meter (120-inch) wide (diameter) image, the optimal viewing distance is between 1.6–2.7 meters (2.7 meters x 1 and 2.7 meters x 1.69).

The bottom edge of the picture is recommended to be positioned at a height of 60–90 cm from the floor.

To achieve a cinema-like effect, the recommended width of the image is at least 0.59 x the viewing distance. On the other hand, a 100–120-inch image is an experience that is already impressive from all normal room viewing distances.

Things that affect size and location

Throwing/reflection ratio

The projector is usually informed of the so-called throw ratio (Throw Ratio), which Describes how a large (or small) projector produces an image at a given distance from the image surface. This can sometimes be mentioned in the technical data as the direct throw distance value. The throw distance directly tells you how close or how far the projector can be positioned from the projection surface and what size image this will produce.

If the projector is placed too close to the image surface, the image will be small, and if it is placed too far away from the image it will become too large and its resolution and brightness will also deteriorate.

The distance of the projector from the image surface and its throw ratio determine the size of the image. (The whole here refers to the width of the image). The width of the image is the throw ratio divided by the distance from the projector to the image surface.

For example, the throw ratio of 1.5 means that from a distance of 200 centimeters, only a 133 centimeter wide image can be obtained (200 centimeters : 1.5 = 133 centimeters). For example, to obtain an image 220 centimeters wide (with a diameter of 100 inches), the distance from the projector’s projection surface must be 220 centimeters x 1.5 = 340 centimeters. Even for a larger image (for example, 200 inches, width 442 centimeters), the projector must be located 5.3 meters from the projection surface (442 centimeters x 1.5).

The throw ratio of the projector is important information when you want a certain size image, for example based on the location and size of the screen.

With the Zoom function, the image size can be adjusted infinitely within certain limits. The wider the zoom, the more flexible the adjustment options.

There are so-called short throw projectors on the market that can project an image of up to 100 inches from a distance of just 1–1.5 meters from the projection surface. Ultra-short throw projectors (ultra short throw) can project an image of 100 inches even closer.

For calculating the throw ratio and the image size, there are handy online calculators. See more about this topic at the end of the article. Calculation of throw ratio and image size.

Zoom adjustment

If the projector has image zoom, i.e. the ability to adjust the size of the image (almost all of them have it), the throw ratio mentioned above is usually indicated in the zoom adjustment range, for example 1.2–1.5, in which case the size of the image on a projector at a distance of 340 centimeters in the previous example can be adjusted with zoom between 283–220 centimeters. Or a 220 centimeter wide image can be obtained at a distance of 264–340 centimeters from the projector.

The projection ratio (H) of a projector tells us the size of the image that the projector produces at a given distance from the projection surface. The width of the image (L) is the distance from the projection surface to the projector (E), divided by the projection ratio value (H) (L=E/H). Or, conversely: the distance from the projection surface to the image is the width of the image (L) multiplied by the projection ratio value (H) (E=LxH).
This can be mentioned in the technical data as the direct throw distance value. The throw distance directly indicates the distance at which the projector can be positioned from the image surface and what size image will be obtained in this case.
When moving the projector further away, the image will be enlarged, and when moving it closer, the image will correspondingly be reduced.

The throw ratio of the projector is important information when you want a certain size image, for example based on the location and size of the screen.
With Zoom, the image size can be adjusted within the limits allowed by the zoom factor.

The BenQ W1050 is a more affordable full HD DLP home theater projector with wide zoom. A 8-inch image is achieved from just 2.8 meters away. Thanks to the separate Sport Mode, the projector is promised to reproduce even fast-paced sports with sharp and smooth images without image tearing. Price range under 700 euros.

Offset

The offset value refers to, how many percent of the image's bottom edge is relative to its height above or below the center of the lens. The offset of the image located in the center of the lens level is 50 percent (half of the image is above the lens and half below it). Similarly, a 100 percent offset means that the bottom edge of the image is at the level of the projector lens, in which case 100 percent of the image is therefore above it. For example, a 120 percent offset means that the bottom edge of the 150 centimeter high image is 30 centimeters above the projector lens center point (positioned on top or below the ceiling).

The projector basically reflects the image directly through the lens (in this case, the center of the image is at the center of the lens plane, and its offset is said to be 50 percent, meaning that half of the image is above the lens and half below it). However, projectors are designed so that the image is reflected above the center of the lens. When the projector is placed on a table or a flat surface, the image is reflected obliquely upward, with the lower edge of the image being either at the level of the video projector, in which case the offset value is said to be 100 percent (100 percent of the image is above the center of the lens).

In general, the lower edge of the image still projects somewhat higher than the projector level. In this case, the offset value is over 100 percent, for example 120 percent. Therefore, with an offset value of 120 percent, the lower edge of the image is located 20 percent of the height of the image above the center of the lens. For example, if the height of the image produced by the projector is 125 centimeters, then with the 120 percent offset value in the example, the lower edge of the image is 125 centimeters x 0.2 = 25 centimeters above the projector lens. The recommended height of the lower edge of the image is 60–90 centimeters from the floor.

When installing the projector on the ceiling (secretly), the upper edge of the image remains 25 centimeters lower than the projector, and the lower edge of the image is 150 centimeters lower (25 + 125 centimeters)..

The bottom edge of the image is recommended to be positioned at a height of 60–90 centimeters from the floor, so this should also be taken into account when choosing a projector.

The image can also be projected by tilting the projector, but in this case the geometry of the image suffers: the upper or lower edge of the image is wider than the other. There is usually a correction for this (Keystone), but the image quality suffers from its use.

To ensure the best image quality, the video projector should always be mounted as directly as possible (with minimal adjustments and adjustments) relative to the image surface.

Lens transfer

Lens Shift is a mechanical method of moving the image relative to the lens. The image can be moved seamlessly up or down from the center of the lens without distortion, and in some projectors it can also be moved horizontally. This makes it possible to install the projector clearly off-center from the center of the image.

Some projectors have what is called Lens Shift, which allows the position of the image to be moved in a kind of mechanical and non-rotational manner, in some models even in a side direction. In this case, the projector can clearly be positioned off to the side from the center line of the image.

The Epson EH-TW9300 Full HD projector includes a 4k scaler and support for high dynamic hdr content. Its contrast ratio is reported to be as high as 1,000,000:1. There are also plenty of adjustments for the image, including a 93-percent vertical adjustment for the image position, and the image can also be moved 47 percent in the side direction as well. The zoom ratio with motorized zoom is 2.1. Also available wirelessly (EH-TW9300W). Price range: 3,000 euros.

Keystone

Keystone or trapezoid correction means the electronic correction of the image's aspect ratio. If the video projector is not exactly perpendicular to the image surface and, for example, points slightly upward, the image is wider at the top than at the bottom. With Keystone correction, this distortion can be corrected digitally, but any excess and unnecessary image processing degrades the playback quality.

The image can also be moved by tilting the projector, but in this case the image dimensions will be distorted (see: Keystone adjustment). However, this is not recommended for home theater use because the correction is done electronically and it will not improve the image quality in any way.

For calculating the throw ratio and the image size, there are handy online calculators. See more about this topic at the end of the article. Calculation of throw ratio and image size.

Considering the intended use

It is often said that a video projector should also be chosen according to its intended use: a certain type is best suited for movie use, while one for sports and gaming is its own.

This relates primarily to two technical characteristics: retail sales and display lag (display/input lag).

A fast-motion image, such as in sports and some games, looks easily jerky if the projector’s operation is not smooth.
When it comes to movies, it is said that the 24-frame refresh rate used in movies is part of the matter and makes the movie ”cinematically natural”.
This does not mean that the projector’s operation cannot be smooth and steady. Often, there are also individual settings for the projector’s controls.

In game play (especially in fast-paced games and multiplayer games) the display lag time should be as small as possible. Playback delay refers to the delay caused by the projector's image processing between the input of the image and its playback. If the playback delay is long, it significantly hinders real-time and fast-paced gameplay. For more serious multiplayer use, the playback delay should not exceed 100 milliseconds. In the best projectors, the figure is 20–30 milliseconds. If gaming is not important, then the value is of no significance.

Image quality and resolution

The video projector should naturally produce the best possible image. This is formed from several aspects, including image resolution, brightness, contrast, color reproduction, and motion. We will explain what these mean and what their practical significance is below.

Accuracy

Resolution (resolution) refers to the number of pixels in the image formed from the pixels and the pixels (pixels) of the image-reproducing display panel. The base level for high-quality image is a projector with full hd resolution. This means that the image is formed from 1,920 x 1,080 pixels.

There are also so-called HD Ready projectors on the market, with a resolution of 1,280 x 720 pixels. Their quality is excellent for DVD and television use, but the price difference between full HD projectors has narrowed, so it is often advisable to choose a full HD model directly. There are also resolutions expressed in exotic letter combinations – such as svga, xga, uxga, wxga, wuxga – which mean different resolution levels derived from the computer world. Only wuxga corresponds to full HD resolution. Uxga and wxga can only achieve HD Ready resolution.

In this context, native resolution or resolution is also often referred to, which refers to the actual number of pixels in the original image. The number of pixels in the image can also be increased or decreased mathematically, in which case we are talking about scaling the image. However, this does not correspond to the original image resolution.

Even larger 4k or UHD projectors with 3,840 x 2,160 resolution offer an even sharper image, which is especially noticeable with large image sizes. With 4k resolution, the image is astonishingly sharp. So far, 4k projectors have been quite expensive, but the price has already dropped below 3,000 euros. 4k material is also starting to be available in good quantities, but it’s not yet a mass-produced product.

Also note that the resolution of the image is also affected by the size of the image (the larger the image, the fewer pixels are located from each other). Therefore, it is not advisable to increase the image size too much, even though there is theoretically a possibility to do so. At normal viewing distances in the living room (3–5 meters), the maximum size of the image could be recommended to be no more than 150 inches. With larger sizes, the image resolution suffers (except for 4K images). So it is not always worth striving for an image that is too large.

In the image, examples of the relationship between the image resolution and the image size and resolution.

Great importance to optics

Just as with cameras, where the lens optics have a very significant impact on image quality, so does the optics of video projectors. The image produced by a high-quality lens no longer looks good when magnified through inaccurate and low-quality lenses onto the image surface.

There are surprisingly large differences in the optics of projectors, but they cannot really be compared without using the eye.

Light, colors and contrast

Light output or power

The unit of luminous flux, or more correctly luminous intensity (or luminous flux), is the lumen (old term: lumen) and its abbreviation lm. This refers, in a simplified way, to The intensity of the light emitted by the light source (the projector lamp) at a given distance and area. The higher the value, the more light. Light makes the image brighter. On the other hand, there must be not too much light. The light must not be blinding, and the black must be black and not gray. High light output also usually means a shorter lamp lifespan.

When it comes to projectors, we are talking about lumens. The term “lumen” comes from the standard for measuring the light output of video projectors.

Typically, the light output of the lamps in video projectors is 800–3,000 lumens. For home theater use, a light output of 1,800–2,500 ANSI lumens is generally recommended.

The amount of light required does not solely depend on the lamp’s light intensity, but also on the path the light travels, how large an area it reflects, the type of surface it reflects off, and the lighting in the space itself.

The intensity of the light decreases in proportion to the distance it travels, so the power of the light decreases the farther the projector is from the fabric. The same goes for the wider area the light covers (larger image). This is the case, for example, with a flashlight: the narrower the beam and the closer the object is, the brighter the light.

The lighting in the room itself also affects the amount of light required. The brighter the room, the more light power is needed to compensate for the room's own light.

A more accurate way to assess the amount of light is to compare the brightness of the light reflected from the projector’s screen surface, or luminance. The unit of luminance is candela per square meter (cd/m²). The unit of luminance is sometimes also used in a non-standard unit called nit (1 nit = 1 cd/m²). However, in the case of projectors, the value of the Japanese system, fL (foot-lambert), is often used.

There should not be too much light. A projector that is too bright will glare and even cause headaches.

In a dark or dimly lit room, a maximum brightness of 12–22 foot-lumen, or 41–75 nits, is usually recommended for the light reflected from the fabric. In a more brightly lit viewing space, a brightness of 20–40 foot-lumen, or 70–137 nits, is recommended.

However, there is no standard in this matter. The brightness of the light depends on the input value of the light source, the distance to the surface to be illuminated, the size of the area to be illuminated, and the reflection properties of the illuminated surface.

Comparing the light output of projectors makes it difficult for device manufacturers to use slightly different settings to measure the value.

As a rule, a high-quality video projector produces a sufficiently bright image even in a semi-dark room – in a brightness level where you can, for example, still read a book.

The brightness of the image also has its downsides – namely, black repetition. Too much light makes the black parts of the image appear gray, so it’s always worth adjusting the light output to match the actual need.

Example video:

Color output power

Some manufacturers, in addition to the light output, also report the so-called color light output, which is means the intensity of light in the different primary colors. Normally, the light output is measured with white light.

Especially the manufacturers of LCD projectors say that Due to the operating principle, low-cost and mid-range LCD projectors would have better color brightness than dlp projectors.. On the other hand, DLP projectors often have better contrast and black reproduction, which is related to how brightness is perceived in the image, and DLP also withstands better image magnification.

Contrasts

The contrast is actually a more important factor for home theater use than the light output. Contrasts mean the largest brightness difference between the darkest (black) and lightest (white) part of the image.

The contrast is expressed as a ratio, for example 1,500:1. A high ratio is better.

Projectors and white screens cannot produce black light, so the contrast ratio must not be infinite. Poor contrast is visible with black and dark colors, which appear more gray than black in this case.

There are several ways to measure contrast, and there is no standard for it, so it is often difficult to compare contrast figures directly with the values provided by manufacturers. The contrast value should be measured and reported preferably as so-called gain contrast.

When comparing contrast, it is also important to mention the dynamic range, that is, how many brightness levels the projector can produce. The more levels, the more uniform the grayscale and color reproduction, for example.

Example video of the contrast:

Color reproduction

The repetition of colors should be as natural as possible and the colors should be pure. The colors should not be emphasized. Evaluating the color repetition is easiest based on the skin color.

When it comes to color reproduction, the term color space and various color space models are often encountered, such as srgb or rec.709. A color space indicates how many different color shades a projector can reproduce. Color space models are different.

The video projector’s settings often allow for truly versatile color adjustments. There are various color space models to choose from, as well as various adjustments for things like brightness, contrast, color saturation, color temperature, and more. For more on this topic, see the section on settings.
The number of adjustments should not be feared. Usually, there are also ready-made settings available according to the intended use, which easily achieve the best result.

The colors perceived by the human eye can be evaluated using the CIE 1931 color diagram. It shows the color space seen by the human eye as a graphical representation in the shape of a horseshoe. Image reproduction devices are capable of reproducing only a portion of the entire color space (the triangular regions in the diagram), for which different standards have been defined. (source of image: http://3.bp.blogspot.com)

Business

In a large picture and with material that includes fast movement, the importance of the business’s flexibility becomes clear. The problems of business and the current image make watching the film tiring. For example, sports and some games place high demands on the fluidity of the business. In movies as well, the fluidity of the business is just as important, although there are different views on this. In movies, the frame rate for the movie screens is ”only” 24 frames per second for historical reasons. This also brings a cinematic atmosphere to the home theater, and for some movies the excessive frame fluidity and resolution are simply not suitable. On the other hand, the online screen speed is especially noticeable as flickering in moving objects.

Projectors usually have various motion enhancement functions, some of which work very well, while others are less effective.

Game play

With large-format displays, gaming gets a whole new dimension. In-game operation should pay attention to the fluidity of the gameplay and the accuracy of the image. In certain games – especially multiplayer games – the image delay, or so-called input lag, should be kept as low as possible (at least under 100 milliseconds; in the best projectors, the delay is even less than 20 milliseconds). Projectors usually have a separate game mode from the operating menu for playing games.

What kind of projector should I choose?

The choice of a video projector actually starts with the choice of the screen.

Which location and size are the most important information. Next, the placement options for the projector are mapped out: ceiling mount, flush mount, fixed installation, or mobile installation, at what distance, and so on.

If the projector is to be placed on the back wall near the ceiling, it must be taken into account what size image it produces from this distance. If the distance is long, more light output is also required, and if the image size increases beyond the recommended size, its resolution suffers.

The choice is also influenced by whether the space can be completely darkened or whether it is even desired to darken it completely; if there is light in the room, then how much. This affects the required light output and also the requirement for contrast.

After that, they are sorted into the options that will produce the desired image size with the desired placement and quality criteria.

An important screen

In principle, the image from the video projector can be reflected onto any light-reflecting but matte surface—even a white wall. The surface must be completely straight and as flat as possible. If the surface is not straight, it distorts the image. Unevenness in the surface reduces the image’s resolution. The surface must also not be shiny.

The best picture is achieved on a high-quality canvas. Reflections on the wall or tablecloth are not recommended.

The overall size of a white canvas is naturally determined by its placement possibilities. The most popular sizes are 90–120 inches with a 16:9 aspect ratio.

White fabrics are fixed to the wall and can be lowered down from the ceiling (including those that rise from the floor!). Fixed fabrics are usually those where the fabric is sewn between black frames. The black frames make it easy to frame the image and add a sense of contrast to the image. The sewn fabric stays straight and does not flutter, for example due to airflow.

The fabric to be lowered should also have black frames, a completely black upper part of the fabric, and an opaque background. The fabric to be lowered can be manual or motorized. The so-called trigger feature means that the fabric descends and rises back up under the control of the projector.

There are differences in the reflectance of white fabrics. The so-called gain value describes how much the fabric reflects light back. However, a gain value of, for example, 1.2 does not mean that the fabric reflects light 1.2 times more than the reference (the Lambert surface). This should be kept in mind when talking about gain values. The light output of video projectors today is so high that there is usually no problem with the brightness of the image. A too high gain value can cause uneven brightness in the image, depending on which direction it is viewed from. A high gain value may be justified in very bright conditions or when using a low-power projector for a large image.

Attention should also be paid to the contrast and repetition of black. Repeating black from a white surface is indeed challenging. Fortunately, the eye and brain are notoriously easy to deceive, so this one succeeds despite the principle of impossibility.

Despite their name, the white fabrics are also available in gray or even black. What is the idea behind them?

If the viewing area can be darkened almost completely – in which case, for example, reading a book is impossible –, white fabric is the best option. If it is not possible to darken the space or the image to be viewed is to be viewed with lights on or otherwise in conditions other than near darkness, gray fabric may be a better choice than white. With white fabric, the darkness of the space blurs the black tones to gray, and the contrast of the image deteriorates, making it unwatchable.

You can improve the black reproduction and contrast of the image by choosing a screen with a gain value of less than 1. Such screens are typically silver-gray in color, with varying degrees of grayness. There are also nearly black screens on the market that are promised to provide a bright and wide-contrast image in a fully-lit room and in daylight. The screens can also be perforated, allowing the installation of home theater system speakers behind them if necessary.

The price range for white fabrics is wide. For example, a 100-inch fabric can be purchased for as little as 100 euros, but it can also cost up to over 2,000 euros.

Grandview is one of the world's largest manufacturers of white fabric, and its range is also very extensive. The range includes, for example, manual, electric, edge-creasing tab-tensioned, fixed, lift-up mobile-use, structural-mounted, and giant public-space specialty white fabrics.

The manual roll screen is the most affordable way to get into the home theater hobby. The Grandview Cyber screen has a white frame, meaning it disappears from view when mounted on the ceiling. The Grandview Cyber screen comes standard with Speed Control, which means that even if you unroll the screen, it smoothly retracts back into its frame. In the photo, the Grandview Cyber 106" 16:9 manual roll screen. Price range 390–370 euros.

The Grandview Fixed 4K screen, designed for home theater use, is permanently installed and is available, as needed, in either the premium matte white fabric material, the high-contrast and bright-colored uhd version, or the pure sound-permeable acoustic fabric. The available frame sizes in Finland vary from 180 inches to 240 inches, depending on the importer. Prices start at 490 euros.

Installation

Installing a projector and a screen is not difficult, but it still requires time, expertise, and knowledge. This is one of the reasons why projectors have not become as widespread as could be expected based on their benefits.

In its simplest form, a video projector can simply be placed on a table, plug in the power and video signal cables (although in some models the image can also be wirelessly projected to the projector), point the projector at a white wall (perhaps preferably on a stage or a white cloth), adjust the image – and voila: the movie night can begin.
Of course, the first time you use a video projector requires some configuration, but after that it’s easy to use. However, often the projector and screen should be installed firmly and with consideration for their characteristics – and before purchasing them, the investment and installation options should already be clear.

Investment in white fabric

The best placement for white fabric is basically on a wall that reflects as little direct light as possible. In this regard, you will probably have to make compromises, but you should probably not place the fabric directly next to the window or against the opposite wall – at least not if the image is intended to be viewed other than through the window when it is completely darkened. If there is a lot of ambient light in the room, there are fabrics on the market that reduce the reflection of ambient light.

Next, it is assessed what the height of the bottom edge of the screen will be from the floor. The recommendation is 60–100 centimeters. This should be taken into account already at an early stage when mapping the location of the projector and the screen, and especially in relation to the placement of the projector and the offset value of the projector. The offset value determines the height at which the bottom edge of the image is positioned relative to the height and distance of the image surface from the projector. Especially in the ceiling installation, the image can easily get too high.

The image can indeed be moved by tilting the projector, and the distortion caused by it can be corrected if necessary with the keystone adjustment found on almost all projectors, but this is not recommended, not even for very minor corrections.

Before the final installation of the screen, it should be ensured where the projector image will be placed. For example, the center point of the screen and the lower edge can be marked with masking tape at this stage, and then proceed to the actual installation of the projector.

Projector in place

The distance of the projector from the screen is therefore determined by the size of the image and the throw ratio of the projector (throw distance).

Typically, the projector is placed somewhere in or behind the viewing area on the ceiling. There are various types of ceiling mounts available for this. The projector is attached to them upside down, and the image is also displayed upside down. Most projectors have the option to turn the image back to the correct orientation. Projectors can also be placed on the back wall using wall mounts if the back wall is not too far from the projection surface and the projector’s throw ratio and zoom allow for this.

The projector can also be placed directly on the table or surface above the viewing area or in front of it.

The cooling fans of projectors can produce some noise, which can be disturbing if the projector is located near the viewing area. It is a good idea to check this before purchasing the projector.

Wiring

Projectors often have many different connections. However, in home use, you rarely need to connect anything other than the power cord and cable for the video signal. This is often the biggest challenge in installing a projector. Few people have electricity already installed in the ceiling. The easiest way to do this is with long wires or cables hidden inside a junction box or conduit – at least for ceiling and wall installation. Wiring a projector that is placed in the center of the room or on a level surface or desk can be a more challenging task.
Almost without exception, the video signal is delivered to the projector in digital form via an HDMI cable. Since the cable runs long (over five meters), the quality of the cable is of great importance. And here we are not talking about the black-out theory of cables. If the length of the HDMI cable exceeds 10–15 meters, you will most likely have to use a so-called HDMI repeater (-repeater/-extender), which strengthens the signal and allows for cable lengths of up to 45 meters.

The image can also be transmitted wirelessly to a projector. Some projectors (at least those from Epson and Optoma) have a built-in wireless receiver and a separate transmitter unit for the program source. There are also separate wireless links available that are connected to the input and output terminals and the signal is transmitted wirelessly between them. There are differences in their functionality, so we recommend sticking with the well-known brands.

Photo preview:

Correction (28.2.2019):

There is an error in the text regarding the sentence describing the throwing ratio.
The width of the image is, of course, obtained by dividing the throwing distance by the throwing ratio, not the other way around.
In the example, therefore, 3 m : 1.2 = 2.5 m, not 1.2 : 3 m = 0.4 m.
The general height recommendation for the same piece of music also intended to state that the viewing distance should be no more than three times the height of the image, and not the other way around.

In collaboration with:

Brand/representatives of the case:
BenQ: www.benq.fi
Denon: www.denon.fi
Epson: www.epson.fi
Focal: www.kruunuradio.fi
Grandview: www.highendstudio.fi
HDthunder: www.hdthunder.fi
KEF: www.highendstudio.fi
Heco: www.hifitalo.fi
Optoma: www.highendstudio.fi
Supra cables: www.hifi.fi
One For All: www.avkomponentti.fi