Comparison Optoma HD146X vs Optoma HD28e

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.

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.

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.

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.

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.

The maximum noise level generated by the projector.

In most models, the main source of noise is the cooling system — it often uses fans to efficiently remove the heat generated by the lamp. Of course, the lower the noise level, the more convenient the projector is to use, the less inconvenience it causes, and the better the sound accompaniment of the “picture” is heard (if it is provided at all). On the other hand, as the size and power increase, the noise level also inevitably increases, and measures to reduce it significantly affect the cost of the projector.

Portable models are the quietest (see "Main purpose") — most of them do not have active cooling and practically do not make noise, except for control keys clicking and other similar sounds. Therefore, this indicator for such projectors may not be indicated at all. The most "loud" are professional projectors — in them the noise level can reach 50 dB (human speech level at medium volume).

The noise level in the ECO mode is significantly reduced, due to the reduction in heat generation. The active cooling system (fan) slows down, thereby significantly reducing noise. Usually, in economy mode, the noise threshold does not exceed 30-40 dB, depending on the model of the projector.

The power consumed by the projector during normal operation. Both the high consumption of the device and the requirements for power supply providing depend on this indicator: for example, heavy professional projectors of 3500 W and above cannot be plugged into standard sockets, they require a special connection format.

Keep in mind that when using traditional mercury or gas discharge lamps, high brightness inevitably requires high power. Energy efficient LED projectors do not have this disadvantage, but they are still relatively uncommon, and LED is not always a suitable type of lamp.