Number of lamps
The number of lamps provided in the design of the projector.
Most modern projectors have
one lamp, but there are also multi-lamp models. More lamps increase the light flow and, accordingly, the brightness of the image provided by the projector. In addition, in models with
4 lamps, it may be possible to continue working even if one of the lamps burns out — the brightness of the remaining ones is enough to provide the desired brightness. In
two-lamp versions, most often you have to change a burned-out lamp.
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.
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, 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
Diagonal 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.
RAM
The amount of RAM installed in the projector.
This parameter is relevant primarily for devices with Android on board (see above), and even for them it is more of a reference than really meaningful parameter. Theoretically, more RAM means better performance and the ability to handle resource-intensive tasks. In fact, RAM is usually quite enough not only for pre-installed software available out of the box, but also for additional applications downloaded by the user. Exceptions are found only among the most "heavy" programmes, such as games; however, such programmes are rarely installed on the projector.
Built-in memory
The amount of built-in memory installed in the projector.
The presence of a built-in storage allows user to store various content — especially video and photos — in the projector and view it directly without connecting external devices. In addition, in Android devices (see above), the same storage is used to install additional software.
When evaluating the amount of available memory, it is worth remembering that part of it will inevitably be occupied by software firmware. Some projector models have an alternative to built-in storage in the form of a memory card slot (see below).
USB C
The number of USB-C ports provided by the projector.
USB-C connectors differ from conventional USB in their smaller size and symmetrical design (the plug can be inserted into the socket in either direction). And as a predecessor, it can have a different interface (3.2 gen1 and 3.2 gen2), which differs in speed — 5 and 10 Gbps, respectively.
As for the number of ports, the larger it is, the more USB-C peripherals can be connected to the projector at the same time.
