Lamp power
The power consumption of the backlight lamp installed in the projector.
Theoretically, the more powerful the lamp, the brighter it is. However, this is only true when comparing lamps of the same type (see above); and even in this case, the brightness may also depend on the nuances of the design. Therefore, when evaluating the capabilities of a lamp, it is worth focus not so much on power, but on the directly claimed brightness in lumens (see below).
But what this parameter directly affects is the total power consumption of the projector: the lamp is the most “greedy” component of the device, compared to it, the power consumption of the rest of the electronics is very small. Also note that many powerful lamps have high heat dissipation and require cooling systems, which affects the size and weight of the projector.
Real resolution
The native resolution of the image produced by the projector matrix.
The minimum for modern projectors is actually
the VGA standard, which assumes a resolution of 800x600 or close to it. The most limited of modern high-definition standards is
HD (720); the classic size of such a frame is 1280x720, but projectors also have other options (up to 1920x720). A more advanced HD format is
Full HD (1080), which also has several variations (the most popular is 1920x1080). And among high-end projectors there are models of
Quad HD,
Ultra HD (4K) and even
Ultra HD (8K) standards.
In general, the higher the resolution, the clearer and more detailed image the projector can produce. On the other hand, this indicator directly affects the cost, and all the benefits of high resolution can only be appreciated if the reproduced content also corresponds to it. Note that modern projectors can work with higher resolutions than the “native” ones – for more details, see “Maximum video resolution”.
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.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.
Throw distance, max
The farthest distance from the screen that the projector can be used on. This is the maximum distance at which the image remains in focus and maintains acceptable brightness — at least enough for viewing in a darkened room on a high-quality screen.
It is necessary to choose according to this parameter taking into account the expected operating conditions and the distances to be dealt with. At the same time, it's ok to have a certain margin for the maximum distance — since, as already mentioned, it is usually indicated for an perfect screen and a darkened room, and such conditions are not always available. Also note that although the throw distances depend on the lens, not every projector with an interchangeable lens allows the installation of more "long-range" optics than the standard one — the device may simply not have enough brightness for an increased distance.
Image size
Size of the image projected by the projector. Usually, it is indicated as a range — from the smallest, at the minimum throw distance, to the largest, at the maximum. About throw distances, see above; here it is worth saying that the choice of diagonal size depends both on the distance between the screen and the audience, and on the format of the projector. For example, to watch a video, the best option is the situation when the distance from the viewer to the image corresponds to 3-4 diagonals, and a relatively large picture can be useful for working with presentations. More detailed recommendations for different situations can be found in special sources; here we only recall that the image must fit on the screen used with the projector.
Video connectors
Inputs for connecting external video sources provided in the projector.
— VGA. Analogue video interface, that considered obsolete, but still quite popular; VGA outputs are found in video technology, as well as in some computer graphics cards. It supports resolutions up to 1280x1024, which allows you to work with 720p video, but more advanced HD standards are out of the question. Audio signal transmission via VGA is not provided, the soundtrack for such a video will have to be connected separately.
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DVI. A video interface primarily used to connect projectors to computers. Initially, it did not provide sound transmission, but this possibility is gradually being introduced. Nowadays, several varieties of DVI are used. So, according to the signal format, purely digital DVI-D and combined DVI-I, which supports digital and analogue video, are distinguished. In both of these varieties, a two-channel digital data transmission format can be used, in which the maximum video resolution reaches 2560x1600 (in single-channel it is 1920x1200). Connectors and plugs DVI-D and DVI-I are compatible with each other if the number of channels matches, or if a single-channel video signal is connected to a two-channel input.
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DisplayPort. A digital interface originally designed for connecting LCD monitors. Modern versions are similar in capabilities to HDMI, they support HD resolutions of 1080p an
...d higher, as well as multi-channel audio transmission. However, such outputs are rare in video devices; the main area of application for DisplayPort has been and remains computer technology. In particular, it is this connector (as well as its reduced version miniDisplayPort) that Apple regularly uses in its computers.
- — DisplayPort v 1.2. DisplayPort v 1.2 has a bandwidth of 17.28 Gbps. This signal transmission standard has full support for FullHD video format. QuadHD and 4K formats are partially supported.
- Display Port v 1.3. The maximum bandwidth of DisplayPort v 1.3 is 25.92 Gbps. This version of DisplayPort provides full support for FullHD and QuadHD formats. 4K and 8K video modes are partially supported.
- Display Port v 1.4. The bandwidth limit of DisplayPort v 1.4 is 32.4 Gbps. This version of DisplayPort features enhanced support for 4K video, including 144Hz refresh rates, while DisplayPort 1.3 only limits 4K to 120Hz. Like the previous version, DisplayPort 1.4 partially supports 8K video modes.
— BNC. Bayonet type connector used to connect coaxial cable. Projectors use this connection to transmit analogue component video (see the relevant paragraph) or uncompressed SDI video. BNC refers to professional interfaces and is found in projectors of the corresponding class.
— S-Video. Analogue interface for video transmission (without work with audio). Provides two channels for transmitting image information, similar to the component input described below. However, on the one hand, S-Video uses only one connector instead of three, on the other hand, the bandwidth of this interface is noticeably lower, it is not suitable for HD resolutions, in light of which it is considered obsolete and is rare, mainly found in specialized video equipment.
— Composite. Initially, a composite interface is called an analogue interface for transmitting video and sound, using 3 separate channels (for the video signal and the left and right audio channels). However, in this case, most often only one connector is meant — for video; audio inputs on projectors are listed separately and are referred to as RCA (audio) (see "Audio connectors"). In general, the composite interface does not have a high picture quality, besides it is not suitable for transmitting an HD image and is considered obsolete. On the other hand, it is very common and is found not only in modern video equipment, but also in outdated ones; for example, you can connect a VHS-VCR to the projector through this interface.
— Component. An interface that is considered the most advanced among modern analogue video standards. The video signal with this connection is divided into three components transmitted over separate cables; this provides good interference resistance and sufficient bandwidth even for HD resolutions. But the sound in this interface is not supported.Service connectors
Service connectors for connecting control equipment, provided in the design of the projector. Specific control options in each case may be different, they should be specified separately.
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COM(RS-232). A specialized connector, originally used in computer technology. In general, it is considered obsolete, it is relatively rare among computers, but it is very popular in various specialized equipment.
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USB (slave). Connector for connecting to the USB port of a PC or laptop. With this connection, the projector acts as a peripheral device and can be controlled from a computer. In addition, relatively recently, portable projectors have appeared that are designed for wired connection to mobile gadgets such as smartphones or tablets; they also indicate the USB port (slave), although the specific connection may be different (for example, 8-pin in Apple devices).
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LAN (RJ45). Standard connector for wired connection to computer networks. A projector connected in this way works as a network device, it can be accessed (with appropriate settings) from any local computer. This can be more convenient than using only one control computer. In addition, other features can be implemented through the LAN — for example, DLNA (see the relevant paragraph).
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HDBaseT. A complex interface used mainly in professional equipme
...nt (see "Main purpose"). In fact, it is an extended version of the LAN described above, it uses the same connectors and cables, but it has more extensive functionality. In addition to LAN and Internet access, HDBaseT provides dedicated control signals, audio and video streaming, and even power up to 100 W.
— 3D Sync. This port allows you to connect a 3D emitter to the projector, which is necessary for the formation of a volumetric image using active 3D technology (see the relevant paragraph). Accordingly, in order to view a stereo image, it is necessary to use active-type 3D glasses. The glasses are synchronized with the 3D emitter, which makes it possible to achieve a clear and understandable stereo image.