[Home Theater Network HDAV.com.cn] If you plan to install the projector in your home theater, don't forget the projection screen. Even if the walls are white, try not to project directly onto the wall; the surface of most walls is very uneven, and the characteristics of the reflected color are completely unknown. (There is also a way to successfully use the wall as a curtain: use a screen paint (such as Screen Goo) to apply a part of the wall that is thick enough to cover any texture changes and that provides a relatively accurate color; , such a screen is fixed and cannot be moved at will.)
Choosing the right projection screen involves many aspects. The following are the most important:
First, the screen aspect ratio
- The aspect ratio of a screen or image is the ratio of its height to its width. Almost all home theater projectors and TVs have a 16:9, which is 1.78:1 native aspect ratio, while most movies are wider with a native aspect ratio of 1.85:1 or 2.39:1.
- If you watch movies and TV shows at the same time, the aspect ratio of the image and the screen sometimes does not match; when they do not match, black bars appear on the top, bottom and sides of the image.
- Many people with projectors tend to have a 2.39:1 screen so that widescreen movies fill the screen without black strips. In this case, if you play a 16:9 image, a "window frame" will appear on either side of the screen.
- The 16:9 projector can fill the 2.39:1 screen in two ways: to adjust the zoom, lens shift and focus control, or to use a separate anamorphic lens. For more information on this, see "10 Things to Consider When Purchasing a Projector."
Second, the size
- The optimal size of the screen depends on your seat distance. An important criterion is visual acuity (visual power) - how far away are you from sitting on the screen? If you sit further afield, you may not be able to see all the details in the image.
- There are a variety of formulas to calculate the optimal seating distance and screen size based on vision; for this purpose, I recommend using the ITU (International Telecommunications Union) recommendation, the seat distance is 3 times the height of the HD screen, is UHD / The height of the 4K screen is 1.5 times regardless of the aspect ratio of the screen. In other words, for HD images:
(sitting distance) = 3 × (screen height) or (screen height) = (sitting distance) / 3
- The size of most display screens is specified by their diagonal measurements. For a 16:9 screen, the height is about half of the diagonal measurement; for a 2.39:1 screen, the height is about 0.4 times the diagonal measurement. (The difference between the width and the diagonal of the 2.39:1 screen is very small. You can say that its height is about 0.4 times the width. Of course, this number is not accurate, but it is very close.)
- For example, if your seat distance is 10 feet (120 inches), the height of the HD screen should be 40 inches, which means that the diagonal measurement of the 16:9 screen is 80 inches, and the 2.39:1 screen diagonal The measured value is 100 inches. For UHD / 4K, the screen height is 80 inches, which means that the 16:9 screen has a diagonal measurement of 160 inches and a 2.39:1 measurement of 200 inches.
- Another criterion is how many fields of view you want to fill with the image. In the above dimensions and distances, 4K / UHD images may require you to turn your head to see everything.
Third, partial shielding function
- To increase the apparent contrast of images with different aspect ratios, black shading materials can be used to cover black strips or window frames.
- Move the masking material in or out depending on the needs of the different aspect ratios.
- Many projector users believe that maintaining a constant image height (CIH) and moving side shielding is the best approach for images with different aspect ratios. This only requires two masking plates on both sides.
- There are also some projector users who advocate a constant image area (CIA), which usually requires four shadow panels. For a 2.39:1 movie, the side shield panel is pulled back while the top and bottom bezels are closed. For a 16:9 TV show, the side panels are closed and the top and bottom panels are pulled back. This is the largest possible image available for any aspect ratio.
- The original aspect ratio of the screen in the CIA setup is usually about 2.0:1, roughly dividing the difference between 16:9 (1.78:1) and 2.39:1.
- The best way to move the masking material is to use an electric system, especially one that can be automatically adjusted in different aspect ratios, but such systems are generally very expensive.
- Many projector users will create their own partial shading system via DIY, either electrically or manually.
Fourth, the material
- Screen material is usually categorized using several parameters, including gain, viewing angle, color accuracy, baseline color (white or gray), and ambient light suppression.
- Gain indicates how much light from the projector is reflected back to the viewing area. The gain value is usually between 0.8 and 3.0, and it is also possible to be larger. The gain of 1.0 is called "unit gain."
- The viewing angle is technically referred to as the "half gain angle"; it is the angle from the dashed line perpendicular to the screen surface at which the brightness of the reflected light is half that measured on the vertical line of the screen. When the viewer views at this angle or a larger angle, the brightness of the image will be darker than the image seen on the axis.
- Generally, the greater the gain, the brighter the image seen on the axis, but the narrower the angle of view.
- A high gain screen is useful if the projector's light output is low.
- High gain screens are prone to "hot spotting", ie one area of ​​the image is brighter than the other areas.
- For a home theater with full control of ambient light and room tones, a white screen with a gain of 1.0 to 1.3 is ideal.
- For projectors with low contrast ratios, the gray screen can increase the perception of contrast.
- Some companies specialize in manufacturing screen materials designed for ultra short throw (UST) projectors.
Five, anti-light curtain
- Light Resistant Curtain (ALR) reflects light from the projector back into the viewing area while reflecting light from other directions away from the viewing area. Their perspective is narrower than that of non-ALR curtains.
- For rooms where ambient light is not fully controlled, or where the walls, floors, ceilings are white or light, the light curtain provides an image that is better than a non-light resistant curtain.
- If it is a large group of people for a sports party, such as watching a game in a well-lit room, the anti-light curtain is very good. Although the image that is not seen by the person on the axis is dimmer, the contrast is lower. (mainly due to the narrow half gain angle.)
Sixth, acoustic transparency
- The commercial cinema places the front speakers behind the screen and lets the sound pass through many dense holes, which is called a sound-transparent screen.
- Place the front left, center and front right (LCR) speakers behind the curtain so that the sound is as real as the person in the curtain, just like being there.
- This is especially important for the 2.39:1 screen: placing the left and right speakers outside the screen "separates" the sound from the vision.
- There are two types of sound-permeable screens that can be used in home theaters: perforated and woven curtains, where the fibers in the material are loose enough to create "holes" that allow sound to penetrate.
- More than 10% of the area on the sound screen is occupied by these holes, which means that the screen reflects less light than those of a solid screen. In this case, the brighter projector works better.
- If it is a perforated material, the speaker needs to be placed within a distance of about 12 inches from the screen, and some equalizers are usually required to increase the medium to high frequencies that are attenuated behind the screen.
- If it is woven material, the speaker can be placed closer to the curtain without the need for an equalizer.
- The sound screen is translucent, so everything behind the screen, including the speakers, should be smooth, black, and no shiny parts, such as logos or drivers, can be seen through the screen.
- The woven translucent curtain contains a separate black base fabric to reduce light penetration.
- In some cases, the pattern of "holes" on the sound-transparent screen may interact with the pixel structure of the projector, resulting in a Moire effect.
Seven, fixed screen or retractable curtain?
- Fixed screen, which is fixed by a metal frame and mounted on a wall or stand up.
- In a retractable screen, the curtain is attached to an electric roller that pulls the screen back into the housing mounted on the ceiling or wall. This is more expensive than a fixed curtain.
- Some home theater enthusiasts will install a flat-panel TV behind the retractable screen, so that you can watch TV at will, and watch the movie better when the screen is down.
- Electric shading systems are difficult to achieve in retractable screens; in most cases, only the sides can be shaded with black material that is independent of the screen itself.
- Some ambient light-suppressing materials cannot be used in retractable curtains because these materials may contain metals, which are generally not rolled up.
Eight, flat screen or curved curtain?
- Large commercial cinemas are typically 2.39:1 curved screens; this corrects optical distortion and reflects more light from the side to the viewer, improving balance.
- Most home theaters are much smaller than commercial theaters, so curved screens are not that important.
- For a 2.39:1 screen projector equipped with an anamorphic lens, a curved curtain is necessary because it corrects an optical distortion called pincushioning.
- There is no need to buy a 16:9 curved screen for a typical home theater.
- Curved screens are generally more expensive due to the increased cost due to the curved frame.
- The curved screen can only be mounted in a fixed frame and cannot be expanded or retracted.
IX. Budget and recommendations
- The price of any curtain depends on the material, size, frame type (retractable or fixed), and whether the frame contains electric shading.
- Here, I will recommend different screens according to different price ranges, 16:9, diagonal about 100 inches, fixed frame screen. For larger sizes, such as 2.39:1, electric shields and retractable enclosures, you may have to pay more.
More fresh and fun home theater information, please pay attention to home theater network http:// (WeChat: cnhifi), the country's most influential home theater audio player interactive media website.
27 inch all in one computer,desktop computer 27 inch,desktop all in one 27 inch,all in one pc 27 inch i5, i5 all in one computer, intel i5 all in one pc, computer all in one core i5
Guangdong Elieken Electronic Technology Co.,Ltd. , https://www.elieken.com