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.
Brightness ANSI Lumens
This parameter largely determines the ability of the projector to work in a well-lit room. For a dark room, 1000 lumens is enough to make the projection picture bright, rich, clear and understandable. But when working in a lit room, the projector will need at least 3500-4000 lumens. Do not confuse ANSI lumens with Peak lumens. These are two different brightness standards. To convert one type of brightness to another, you need to multiply Peak lumens by 10-12. The result will be an approximate value of ANSI Lumens.
However, experts do not recommend chasing high ANSI lumen brightness values. There are many professional projectors with brightness up to 3500 lm. The lower the brightness, the lower the power consumption, and at the same time, the life of the illuminator increases. Of course, if the projector will be installed in a work office or classroom where good lighting is required, it is recommended to purchase a model with ANSI Lumens brightness of 4000 lumens and more.
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.
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 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.
Throw ratio
The projector's throw distance is vital in determining what size projection screen to use and how far away it should be from the projector. Most projectors have a variable throw ratio. In the extreme positions, these are wide-angle mode (smallest value) and telephoto lens mode (largest value). Knowing these values, you will be able to determine the range of throw distances within which the projector must be placed in order for the projected image to match the specified dimensions of the projection screen.
According to these values, you need to check or set the optical zoom. We divide the larger value by the smaller value, and we get a figure, for example 1.33-2.16: 1.
If we want to calculate whether this projector is suitable for a certain image size, we do this: 1.33*3 (image width)=the distance at which the projector should hang.
Optical zoom
The magnification range of optical zoom that the projector can provide.
Optical magnification of the image is carried out due to the operation of the lenses in the projector lens. With such an magnification, the size of the entire image changes; this can be useful both for adjusting the “picture” to the screen size, and for detailed viewing of individual details (the main thing is that these details do not crawl out of the screen when enlarged). In general,
optical zoom is considered more advanced than digital one, because it allows user to adjust the diagonal without moving the projector, and maintains the original resolution of the "picture" regardless of the magnification. However lenses with such an possibility ("zoom lenses") are more complicated and more expensive than fixed optics, but the difference in price is almost imperceptible compared to the cost of the projectors themselves.
Wi-Fi
Wi-Fi standard supported by the projector.
Wi-Fi is known mainly as a method of wirelessly connecting to the Internet and local networks. In addition, more recently, this technology has also been used for direct connections between wireless devices. Accordingly, the methods of using Wi-Fi in projectors may also be different. Thus, some models are capable of connecting to local networks to work with content via DLNA (see above); in others, such a connection is used for control from a computer or other network device; in others, a “remote control” like a smartphone or tablet can connect directly via Wi-Fi.
As for Wi-Fi versions, the most popular options in modern technology - Wi-Fi 4 (802.11n) and Wi-Fi 5 (802.11ac) - are quite compatible with each other, and the difference between them in this case is not critical. Therefore, you don’t need to pay much attention to these details when choosing.
There are also
Wi-Fi ready projectors, which do not have Wi-Fi out of the box, but when connecting the appropriate adapter (purchased separately) are capable of a wireless connection.
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.