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.
Static contrast
The static contrast of the image provided by the projector.
Static contrast refers to the maximum difference between the brightest white light and the darkest black that a projector can provide within a single frame. Unlike dynamic contrast (see below), this parameter describes not conditional, but quite real capabilities of the device, achievable without the use of any additional tricks like auto-brightness. And since the quality of colour reproduction and detailing depend on contrast, the higher this indicator, the lower the likelihood that details will be indistinguishable in bright or dark areas.
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.
USB 2.0
The number of USB 2.0 ports provided by the projector.
Do not confuse these connectors with USB slave (see "Management ports") — in this case we are talking about
USB ports for various peripherals. Most often, these ports are used for direct playback of content from flash drives and other storages (for example, external HDDs). At the same time, we note that video viewing is not available in some projectors (only photos), in others a very limited set of formats may be supported. However, a direct connection is often more convenient than viewing through a computer or other device. The USB ports can also be used for other purposes, such as updating firmware, transferring files between a flash drive and the projector's built-in storage, or even for keyboards/mouses (in Android devices, see above).
The USB 2.0 standard itself is considered obsolete, but it is quite enough for projectors, and newer peripherals are fully compatible with such connectors. At the same time, you rarely have to connect more than one external device to the projector at a time, so there are few models with more than one USB 2.0.
Number of speakers
The number of built-in speakers provided in the projector.
The
presence of speakers in itself allows user to play sound (for example, accompaniment to the displayed video) without speakers and other additional equipment. However the quality of such sound usually turns out to be low; for a clear sound, you still need external sound system. However, in some cases this is quite enough; in addition, there are projectors with advanced built-in speakers.
The number of speakers can be one or two. In the first case, we are talking only about the playback of monophonic sound, without any surround effect. And two speakers already represent a stereo system. The subwoofer is considered a separate function and does not affect the number of speakers in this paragraph.
Sound power
The nominal power of the sound system installed in the projector.
The higher this power, the louder the sound the device can produce, the better it will be heard in a large room and/or noisy environment. At the same time, it is worth noting two nuances. First, built-in speakers are usually made relatively low-power — otherwise they would take up too much space. Secondly, most modern projectors allow the connection of external sound system (see "Audio connectors"), more powerful than the built-in one. So it makes sense to pay attention to this indicator if you initially plan to use the "native" sound of the projector. Detailed recommendations on the required power for certain conditions can be found in special sources.
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.