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.
Size
The size of the panel/chip affects the depth and final quality of the image. The larger the panel/chip, the more light it is able to process, which means the picture will be clearer and more structured. The average projector has a sensor of 0.5-0.7″, advanced projectors use sensors of 1.2-1.5″ and more.
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.
Keystone correction (vert), ±
Vertical keystone correction allows you to align the image when the projection ray is shifted from the centre of the screen in a vertical plane. If the projector is suspended from the ceiling and shines from top to bottom, a vertical keystone occurs. And the function of vertical keystone correction allows you to align the picture.
In most cases, projectors can only correct vertical keystone. But the keystone can also be horizontal if the projection ray is offset from the centre of the screen in the horizontal plane. Advanced models are often equipped with an auto keystone correction feature (see the relevant paragraph). In this case, the keystone is aligned in a fully automatic mode, without user participation.
Keystone correction (horizontal), ±
Horizontal keystone correction allows you to straighten the picture if the projection ray is offset from the centre of the screen in the horizontal plane. A horizontal keystone effect occurs when the projector shines on the screen not from above, as in most cases, but from the side. A horizontal keystone is often combined with a vertical one. In this case, it is necessary to correct the distortion both horizontally and vertically.
Projectors with horizontal keystone correction almost always have vertical keystone correction capability (see the relevant paragraph).
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.
HDMI version
HDMI interface version supported by the projector.
About the interface itself, see above, and its different versions differ in maximum resolution and other features:
— v 1.4. The version released back in 2009. Despite this, it has quite decent specifications, due to which it continues to be used in modern video equipment. Specific features of HDMI v1.4 include 3D support, the ability to work with 4K video (4096x2160) at 24 fps and with Full HD at 120 fps. In addition to the original version, there are also improved modifications — v.1.4a and v.1.4b; they differ only in some 3D-related improvements.
– v 2.0. Standard introduced in 2014. Thanks to the increased bandwidth compared to v 1.4, it allows you to transfer 4K video at speeds up to 60 fps, as well as up to 32 channels and up to 4 audio streams simultaneously. In addition, this version was the first to introduce support for the 21:9 ultra-wide format, and the v2.0a update introduced HDR compatibility, with further enhancements to this feature in version 2.0b.
— v 2.1. A version released in 2017 also known as HDMI Ultra High Speed. The data transfer rate has indeed been significantly increased, allowing the support for video up to 10K at 120 frames per second. In addition, some improvements regarding HDR have been made. Note that connecting via HDMI v2.1 requires the use of special cables, although the basic features remain available when working with standard cables.
