Lamp model
The lamp model that the projector is designed for. Most projectors come with lamps included, so this information is not needed for normal use. But when looking for a spare lamp or replacement, information about model can be very useful: finding a spare part by the exact name is much easier than by general data like the brand of the projector.
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.
Dynamic contrast
The dynamic image contrast provided by the projector.
Dynamic contrast ratio is the ratio between the brightest white and darkest black colour that a projector can produce. Recall that 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. However, dynamic contrast is a rather specific parameter. The fact is that when it is calculated, the brightest white at the maximum brightness settings and the darkest black at the minimum are taken into account. As a result, the figures in this column can be very impressive, but it is impossible to achieve such a contrast within one frame.
By introducing this parameter, the manufacturers went to a certain trick. However, this is not to say that dynamic contrast has nothing to do with image quality at all. Projectors can use automatic brightness control, in which the overall brightness, depending on the "picture" on the screen, can increase or decrease. This format of work is based on the fact that the human eye does not need too bright areas on a general dark background and very dark areas on a bright one, the image is normally perceived even without it. The maximum brightness difference achievable in this mode of operation is exactly what described by dynamic contrast.
Horizontal frequency
Horizontal frequency supported by the projector.
This parameter is relevant when working with analogue video signal. In such a video, the image is formed line by line: each pixel in the line is highlighted in turn, then the next line is highlighted, and so on. The horizontal frequency describes how many times per second the backlight beam runs from edge to edge of the screen. For normal playback, the projector must support the same refresh rate as the input signal was recorded. However, most models support a fairly wide range of frequencies, and there are no problems with support. Also note that if you are not a professional, then when choosing a projector, it is quite possible to focus on the frame rate (see below) — this parameter is simpler and more intuitive, and support for a certain frame rate automatically means support for the corresponding line rate.
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.
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.
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.
