Since the appearance on the home appliance market, projectors have changed a lot. These are not the same expensive devices with no less expensive maintenance, which could only be used in the dark. Today, the projector allows you to view photos and videos, it can easily replace a TV or personal computer screen. And the price of models that support Full HD resolution is equal to the cost of 40-inch television sets. It's time to take advantage of this technology and become the proud owner of a home theater with a truly gigantic screen with a 300-inch diagonal, which is about 7.62 m.
Picture
The main parameter for choosing a projector is image quality. But how to do this if the much-needed assessment of several models of an expensive device cannot be made due to the lack of a viewing room?
You can evaluate the image quality of projectors by the following parameters:
- imaging technology;
- matrix size and resolution;
- contrast;
- brightness;
- focal length.
First of all, image quality depends on projection technology. Three technologies are currently used: DLP, LCD and LCOS.
DLP
DLP (Digital Light Processing) uses a matrix of tilt-changing micromirrors that direct light into focusing lenses. Staining a beam of light occurs in different ways. Some manufacturers use a rapidly rotating three-color wheel. At the same time, the eye sees alternating monochrome images, which may affect some people, and also creates a rainbow effect that interferes with viewing. Others apply three micromirror arrays for each color separately (3DLP technology). Projectors using 3DLP technology are among the best, but also the most expensive projectors.
LCD
LCD technology (Liquid Crystal Display) uses three liquid crystal matrices to form the red, green, and blue components of the video signal. The light flux of a metal halide lamp passing through a prism or sequence of dichroic filters passing one part of the spectrum and reflecting the other is divided into three components. Each is directed through its own LCD-matrix, which, by changing the flow of light passing through each pixel, creates a single-color image. The combination of the three components produces a multi-color projection. Among the disadvantages of this technology is the low contrast of the image (due to the fact that the crystal transmits light when closed, and the matrix bandwidth does not exceed 7%).
LCOS
LCOS (Eng. Liquid Crystal on Silicon) is based on the previous two. But the light does not pass through the liquid crystal matrix, but is reflected by liquid crystals on silicone. Thanks to this, a high-quality image is obtained without the disadvantages of DLP and LCD technologies. In addition, it becomes possible to increase the density of pixels and achieve high resolution images. But the price of LCOS projectors is quite high, which so far limits their use by movie theaters and large presentation rooms.
LED
LED technology (Eng. Light-Emitting Diode, LED) for creating an image uses one of the above technologies with the difference that the light source is an LED matrix. At the same time, there is no need to replace lamps, energy consumption is reduced. The guaranteed life of the LED matrix is 25 thousand hours. The disadvantage is the low luminous flux not exceeding 2000 lumens.
The laser projector is equipped with a group of laser diodes in primary colors. Less expensive are hybrid laser-LED projectors, which combine a blue diode laser, a green fluorescent element and red LEDs to achieve high image brightness .
Resolution
Resolution is determined by the number of pixels. For a high-quality image, these parameters of the video projector and source must match. You can play a signal with a different resolution, but the image will be distorted by compression algorithms.
Popular resolutions are 1280 x 768 WXGA, 1280 x 720 HD, 1920 x 1080 Full HD, 1920 x 1200 WUXGA.
Brightness
Luminous flux is measured in lumens. Projectors with a brightness of 2000-3000 lumens are used in classrooms and small conference rooms. Luminous flux of 3000-4500 lumens is suitable for large conference halls. The brightness of the image in this case is sufficient so as not to darken the room. Superbright projectors with more than 4,500 lumens are used at concerts, in nightclubs, churches, etc. The cheapest and smallest portable projectors with a luminous flux of less than 2000 lumens require full or partial dimming of the room.
Contrast
The ratio of the highest and lowest brightness of the screen is called the contrast of the projector. For example, a contrast ratio of 10,000: 1 indicates that the brightness of white is 10,000 times that of black. In a darkened room, contrast is leveled by third-party light sources and inferior in importance to the projector's light output.
Lens
Video projectors can be equipped with lenses with the ability to manually or automatically change the focal length. This is necessary to resize the image without moving the projector itself.
Also, the lens is characterized by the ratio of the distance to the screen to its size. Projectors are telephoto (2–8: 1), standard (1-2) and short-focus (less than 1).
Features of LED projectors
- Indoor use requires blackout for maximum clarity and brightness.
- Devices with a luminous flux of up to 300 lumens are designed for a screen width of 0.2 m, and more than 500 lumens - up to 3 m.
- Suitable for mobile home theater. They are not a full replacement for projectors with metal halide lamps.
- Portability is achieved by the presence of an external power supply, the ability to connect wirelessly.
- Models with a high luminous flux are characterized by a high noise level, therefore they are suitable for use in public places.
- Energy consumption is minimal.
LED Projector: Overview of Popular Models
Every day new models of projectors appear on the market, the light source in which are LEDs. Below we consider only those LED projectors, reviews of which were positive. So, let's begin.
ViewSonic PLED-W800 Mini LED Projector is a handheld device designed for business presentations, as they say, “on the go”. But, according to consumers, the power of the light flux allows it to be used at home.
ViewSonic, a California-based company, has specialized in projection equipment since the late 1980s. And a few years ago, she became the pioneer of a new line of mini-LED projectors with the PLED-W500 model. Now available models W200, W600 and W800.
The numbers in the model name correspond to the power of the luminous flux in lumens. On paper, a comparison with the power of metal halide lamps, which exceeds 2,000 lumens, does not speak in favor of the LED projector, but in practice, judging by customer reviews, the device illuminates the screen brighter than one would expect. The portable device is capable of delivering PowerPoint presentations, giving an 80-inch HD 1280 x 720 image at a distance of 2.5 m with brightness that does not require dimming the room. However, to watch movies, you will need to close the curtains and turn on the Movie mode, which will give the image a more natural color. The compactness of the device required sacrificing a change in focal length. But there is a mount for mounting on a tripod. If the projector is tilted relative to the screen, the image will be automatically corrected.
ViewSonic Pro9000 is a hybrid laser-LED projector that is ideal for home theater. The beautiful colors provided by the DarkChip3 chip, the high clarity of the Full HD image, 16,000 lumens of light output and a contrast of 100,000: 1 are what the consumer especially likes. The design of the projector does not use lamps and filters, which reduces the cost of operating the device to almost zero.
LG PH550, PW1000, PW1500 - LED home projectors introduced in January 2016. Luminous flux in lumens and resolution (H for 1280 x 720 and W for 1280 x 800) are indicated in the device name. The PH550 model is equipped with a 2.5-hour battery, Bluetooth sound, wireless connection with Android OS devices. The PW1000, in addition, is equipped with a digital TV tuner and 3D-compatible, and the brightness of the PW1500 speaks of its merits.
Vivitek Qumi Q5 is a portable mini-LED projector with a resolution of 1600 x 1200, 500 lumens brightness and 3D support. The screen size is 30-90 inches (0.76-2.3 m) at a distance of 1-3 m. There is also a built-in player, 4 GB memory, a USB port, a wireless connection, an Internet browser and a battery. Users note excellent color reproduction, contrast, image quality, design and compactness, but some are unhappy with the noise of the fan and the insufficient volume of the device.
The Qumi range also includes LED projectors Q4, Q6, Q7 Lite, Q7 Plus. With the growth of the number, the brightness also increases, which in the latest model reaches 1000 lumens. The contrast is 30,000: 1, resolution 1280 x 800. The ability to control the projector using mobile devices running Android or iOS is implemented. There is a correction of the trapezoid, the displacement of the lenses in the horizontal and vertical directions, optical zoom.
The Vivitek Qumi projectors are manufactured by the Taiwanese corporation Delta Electronics.
Optoma Products
Optoma offers the following LED projectors.
ML750e is a compact and lightweight (less than 400 g) unit. This is a portable LED-projector designed for games, watching movies and presentations without using a PC; There is a built-in memory and a slot for connecting a micro SD card. Resolution 1280 x 800, contrast 15,000: 1, screen size 17-100 inches, projection distance 0.5-3.2 m. Consumes 65 watts in operation and 0.5 watts in standby mode. Users are very pleased with the ultra-mobility and versatility.
ML1500e is equipped with a built-in media player, document viewers, stereo sound, wireless connection and a memory card. Resolution 1280 x 800, contrast 20,000: 1, screen size 17-100 inches, projection distance 0.5-3 m. Consumes 145 watts.
HD91 + - used the second generation LEDs, Full 3D 1080 p image, optical zoom. Contrast 600,000: 1, screen size 30-300 inches, projection distance 1.5-19 m. Consumes 245 watts in bright mode and 150 watts in movie viewing mode. There are no complaints from users.
Optoma, a global corporation headquartered in the United States, Europe, and Asia, produces projection and audio devices for business, education, and home use. It was founded in 2002 in Shanghai, China.
Projectors from BenQ
BenQ company produces portable LED projectors GP30, GP3, GP20.
GP30 is a short-focus (40-inch screen at a distance of 1 m) multimedia LED projector with a luminous flux of 900 lumens. According to the manufacturer, it is distinguished by the presence of stereo sound with SRS HD, support for technology for wireless transmission of content MHL and WiDi. The GP3 and GP20 models have a brightness of 300 and 700 lumens, respectively. Resolution 1280 x 800, contrast 100,000: 1, tilt correction +/- 40 °. In 2014, the Taiwanese company BenQ became the world leader in sales of high-definition projectors, and the total number of models sold exceeded 1 million.
NEC NP-L102W is a 1000-lumen LED projector with 1 GB of internal memory and an SD card slot for up to 32 GB, which allows you to leave your laptop at home and make presentations from a flash drive. The built-in viewer for office programs allows you to open MS Office files and documents in PDF format. The design does not use rotating filters, which, according to reviews, reduces noise and eliminates the need to care for them. Resolution 1280 x 800, contrast 10,000: 1. The Japanese company NEC Display Solutions, the manufacturer of this projector, has been operating for over 20 years.
Panasonic
In the Panasonic PT-RZ470U professional projector, the lamp is replaced by an LED laser system with a light flux of 3,500 lumens. Resolution 1920 x 1200, contrast 20,000: 1, screen size 40-300 inches, distance to the screen - 2.6-10 m. According to user reviews, the hybrid light source has higher color purity, and the Digital Link system allows HDMI transmission uncompressed HD video, sound, and commands over a single Cat5 cable up to 100 meters away. Panasonic was at the forefront of the projector industry, starting production in 1975. And it continues to occupy a leading position to this day, having a record brightness of the projector of 9000 lumens and the first to introduce wireless technology into devices of this type. Users are very pleased with the overall image quality of the new type of projector, but the level of contrast and color reproduction, they say, is still at an average level.
New from Casio
The Japanese company Casio, which was the first to launch hybrid laser-LED projectors, offers affordable models XJ-V110W, XJ-V10X, XJ-V110W, XJ-F210WN, XJ-F100W, XJ-F20XN, XJ-F10X, the brightness of which reaches 3500 lumens. Contrast of new 20,000: 1 projectors, tilt correction, wired or wireless network connectivity.
Acer
Acer also produces portable LED projectors K137i, K138ST, K335 with a resolution of 1280 x 800 pixels and a luminous flux of 700, 800 and 1000 lumens, respectively. Contrast 10,000: 1, screen size 17-100 / 25-100 / 30-100 inches, screen distance 0.6-3.2 / 0.4-1.7 / 0.9-3.0 m, tilt correction + / -40 °, support for PDF, MS Office, power consumption 75/80/135 watts. Owner reviews are mostly positive.
Chinese lanterns
It is impossible not to mention that the market was flooded with cheap Chinese LED projectors, reviews of which are extremely unpleasant. An example is the Digital Galaxy DG-757 and Fugetek FG-637. According to consumers, with the declared brightness of 2800 and 2000 lumens, the real one turned out to be less than 140 and 90 lumens, respectively. This, as well as the huge unevenness of brightness and sharpness, technology 20 years ago once again confirms the proverb "avaricious pays twice."