Service life
Minimum projector lamp life as stated by the manufacturer. Specified by the total time of continuous operation. Note that if the projector was operated without violations, then upon reaching this time, the lamp will not necessarily fail — on the contrary, it can work for quite a long time. However, when evaluating durability, it is best to focus on the claimed service life.
Service life (energy-saving)
When working in economy mode, the brightness of the backlight is noticeably reduced, on average by 30-50%. With a decrease in brightness, heat dissipation also decreases, which saves the working life of the illuminator, thereby increasing the lamp life. Thus, the ECO mode allows you to extend the lamp life by an average of 30%. If the typical projector lamp life is 4000 hours, regular use of the ECO mode will extend the backlight life to approximately 5500 hours.
Brightness
The brightness of the image produced by the projector at maximum backlight brightness. Usually, the average brightness of the screen, derived from a special formula, is indicated. The higher it is, the less the image depends on ambient light: a bright projector can provide a clearly visible image even in daylight, but a dim one will require dimming. On the other hand, increasing brightness reduces contrast and accuracy of colour reproduction.
Accordingly, when choosing this parameter, you need to consider the conditions in which you plan to use the projector. So, for office or school/university use, a brightness of at least 3000 lm is desirable — this allows you to get normal visibility without obscuring the room. In turn, among the top models a very low brightness can be found, because. such projectors are usually installed in rooms specially designed for them with good darkness level. And in ultra-compact devices it is impossible to achieve high brightness for technical reasons.
Detailed recommendations on the optimal brightness for certain conditions can be found in special sources. Here we note that anyway, it is worth choosing according to this indicator with some margin. As mentioned above, as brightness increases, contrast and colour quality decrease, and you may need to use the projector at a reduced brightness to achieve the desired picture quality.
Colour rendering
The number of individual colour shades that the projector is capable of displaying.
The minimum indicator for modern projection technology is actually 16 million colours (more precisely, 16.7 million is a standard number associated with the features of digital image processing). In the most advanced models, this value can exceed 1 billion. However, two nuances should be taken into account here: firstly, the human eye is able to recognize only about 10 million colour shades, and secondly, not a single modern image output device (projectors, monitors, etc.) cannot cover the entire spectrum of colours visible to the human eye. Therefore, impressive colour performance is more of a marketing ploy than a real indicator of image quality, and in fact it makes sense to pay attention to other characteristics — primarily brightness and contrast (see above), as well as specific data like a colour gamut chart.
Technology
The technology by which the projector sensor is built.
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DLP. This technology is based on a chip with thousands of rotary micromirrors. Each such mirror corresponds to one pixel and has two fixed positions — “lit” and “darkened”. In most DLP projectors, there is only one sensor, and the output of a colour image is provided by the colour wheel, thanks to which the projector alternately displays the red, green and blue image; they are replaced so quickly that the viewer perceives not individual frames, but a whole colour picture. Compared to LCD models (see related section), these single-sensor projectors are more compact and offer better image contrast with deep black levels (which improves black and white image quality). However, the brightness of the colour image in DLP devices is relatively low, in addition, they are subject to the "rainbow effect": in dynamic scenes, colour artifacts may be noticeable due to the mismatch of red, green and blue image components. Three-sensor DLP projectors don`t have these shortcomings; however, such a design is very expensive, so it is found rarely, mainly among premium devices.
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3LCD. Technology based on the use of translucent LCD sensors. There are three such sensors, each of them is translucent with its base colour (red, green or blue), and the final colour “picture” is formed from three images simultaneously superimposed on each other. Thanks to
...this format of operation, you can achieve brighter, more saturated colours than in single-sensor DLP projectors (see the relevant paragraph); in addition, this technology is completely devoid of the "rainbow effect". Among its shortcomings are the relatively low contrast ratio (in particular, due to the low black depth) and the larger size of the projectors.
— LCD(Liquid Crystal Display) — a colour rendering technology based on the modulation of light by liquid crystals. Do not confuse LCD and 3LCD sensors. 3LCD technology forms an image from three separate light streams, and in an LCD sensor, the image follows immediately from a single light beam. Sensors of this type provide a stable, contrasting and colour-rich image. Among the shortcomings of the technology, one can note the glimpse of the light grating, if you look at the picture from a close distance. Additionally, the substrate of LCD sensors is prone to fading, due to which the blue colour may begin to turn yellow over time (note that this can happen after a long time of active operation). LCD sensors require periodic maintenance, the service comes down to cleaning the air filter. LCD-sensor projectors are usually compact in size and light in weight, such models are prone to heat, and the noise threshold is above average.
— LCoS. A technology that combines the properties of DLP and LCD. Like LCD, it provides three separate sensors for the three primary colours (red, green, blue), and the final colour image is formed by the simultaneous superposition of these three components. The difference lies in the fact that in LCoS projectors the sensors are not translucent, but reflective. Thanks to this, you can achieve excellent contrast (as in DLP) combined with bright, high-quality colours without the "rainbow effect" (as in LCD). The main drawback of this technology is the impressive cost, which is why it is used mainly in premium projectors.Max. video resolution
The actual maximum frame resolution that the projector is capable of processing and displaying.
Many models allow project images at a higher resolution than the actual resolution of the projector matrix (see above). For example, a 1920x1080 video can be displayed on a device with a frame size of 1024x768. However, the quality of such an image will be noticeably lower than on a projector, which initially has a resolution of 1920x1080.
The maximum resolution is closely related to both the overall picture quality and the size of the projection screen. The higher the resolution, the sharper the image details become. Of course, the screen size itself should be taken into account. The fact is that on a 40-50″ projection surface there will not be much difference between the Quad HD and 4K formats. A high-resolution picture will be able to show itself on a truly large screen.
Image format support
Image formats supported by the projector.
In this case, format means the aspect ratio of the image. The general rule in this case is that the projector must support the same format in which the original content is recorded. Otherwise, the image will either be stretched in height or width, or with black stripes on the sides or top-bottom. Specifically, the formats can be divided into three main categories:
— Traditional, or
rectangular. Classic formats in which the height of the picture is not much less than the width. The most popular options are 4:3, widely used in analogue TV, and 5:4, common in computer technology. Traditional formats are well suited for presentations, working with documents and graphics, and other similar tasks.
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Widescreen — formats in which the frame width is significantly (more than 1.5 times) greater than the height. The most popular of these standards are 16:9 and 16:10. These aspect ratios are well suited for games and movies; in particular, most high-definition content (HD 720p and above) is recorded in widescreen format.
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Extra wide. The formats are even wider than the widescreen ones described above — for example, 21:9. Mainly used in cinematography.
It is worth noting that many modern projectors are able to work with several types of formats at once — for example, with classic 4:3 and
...wide-angle 16:9.Rear projection
The ability of the projector to operate in the
rear projection mode (“mirroring” the image).
There are two main types of rear projection. Most often, horizontal mirroring is found in projectors — it is used when installing the device behind a translucent screen. Vertical inversion, in turn, is used in projectors with fixed keystone correction — due to their design, when mounted under the ceiling, such devices must be turned upside down, which requires the corresponding correction of the displayed image.
Throw distance, min
The closest distance to the screen that the projector can be used on. Typically, this is the minimum distance at which the image from the projector remains in focus.
This parameter is especially important if the device is to be placed at a small distance from the screen (for example, in a cramped room). Some modern projectors are able to work normally at a distance of 10 – 20 cm. Also note that the throw distances are determined primarily by the lens, and if the initial range of these distances does not suit you, perhaps the situation can be solved by replacing the optics.