Short-phocus projectors: varieties and rules of operation

Projector – one of the most important in the office and educational institution of instruments. But even such a private subtype, like short-focus projectors, has at least two varieties. Their features, as well as the rules of exploitation, must be taken into account by all the buyer.


It is customary to allocate three fundamental groups of this type of technology along the length of the focus, that is, by the interval, separating projector from the plane of the image.

  • Long-focus models turned out to be the most simple, and therefore they managed to create before all.

  • Short-phocus projector mainly used in the office sphere. With it, it is easy to organize a presentation of a new product, a project or organization as a whole. The same technique is used in educational institutions, and in other places where something needs professionally illustrate.

  • But if the room is relatively small, it will be better suitable Ultra-duccophocus apparatus. His willingly use at home.

One way or another, both of these types of projection systems are:

  • put not far from the screen, which avoids the use of extended cables;
  • are installed quickly and without any problems;
  • make it possible to “imitate the cinema” in a small volume, issuing a widescreen picture;
  • do not blind some of those present, even speakers and operators;
  • Do not discard shades.

The difference between models with a short focal length and ultrashort fulfillment is quite. It is primarily in the so-called projection coefficient.

In short-focus models, the proportion of the optimal distance to the screen and the width of the screen itself ranges from 0.5 to 1.5. Ultrakorotkoofocus – it is less ½. Therefore, the diagonal of the displayed picture is even at a distance of less than 50 cm may be more than 2 meters.

Review of species

Projectors can be classified into two main varieties – laser and interactive. It is worth considering every kind of more detail.


These devices are directed to the laser rays on the screen. The signal transmitted in this way is constantly changing. In addition to the laser itself, inside contains a gallowetric scanner or an acousto-color flavor. And the device includes dichroic mirrors and some other optical parts. If the image is encoded in one color, only one laser is needed; Projection in RGB format requires you to use three optical sources. Laser projectors can work confidently on different planes. These are sources of particularly clear and very intensive graphics. Such equipment is suitable even to demonstrate three-dimensional drawings and various logos.

DMX protocol is used to control, but in a number of models there is a DAC controller. But it must be borne in mind that lasers of various types can be used in the projector. So, systems based on diode lasers having direct pumps received quite widespread. In addition to them, solid-state systems with pumping through diodes and doubling frequency can be used. But the gas lasers in projector technique have not been applied for almost 15 years.

Mostly laser projectors are used in cinemas and other professional sphere.


This is not just a device capable of displaying a screen, but a fundamentally new level of image display. With them can be interacting, as if with touch surfaces. The main difference is the presence of a special sensor, most often infrared, which is directed towards the screen. The latest models of interactive projectors, in contrast to past generations, can respond not only to special markers, but also directly with fingers.


It is useful to consider not a firm, in general, but specific product samples. And the first in the queue turns out to be particularly bright Epson EH-LS100 Ultra-Corobofocus Projector. During the daytime, the device replaces the TV diagonal TV from 60 to 70 inches. In the evening, you can deploy a screen with a diagonal to 130 inches. The rational distance to the screen will in the first case will be equal to 14 cm, and in the second – 43 cm; To simplify movement, use the branded sliding stand.

Three-pageing technology avoids reduction of brightness when displaying intermediate colors. The efficiency of using a light flux is 50% higher than that of competing models. The light source is designed for long-term use. Epson branded concept orients on the use of external acoustics and smart systems. The product is great for home theater.

It is worth noting I Panasonic TX-100FP1E. This projector externally looks stylish, differs even among those models that they have a formal reward for the design of the case. 32 W acoustic system was introduced into the device. This is a new relevant trend in the development of systems for home theater. Failure to integrate smart systems, as in the case of Epson equipment, is primarily due to the fact that many people prefer external equipment.

And also deserves the projector LG HF85JS, Equipped with advanced 4-nuclear processor. Easy and compact device equipped with a built-in smart TV unit. Used decent acoustics. Designers took care of high quality Wi-Fi connection. The weight of the product is 3 kg, and its movement is possible without any problems.

Recommendations for choosing

The most important parameter in the selection of projectors is the area of ​​their application. Typically, such devices put in classrooms, office consulting rooms and other places where electrical lighting have to use. Therefore, it is necessary to find out if they can give a good picture in such conditions. No less important mobility, because work in the office or at school should not be chained to one place. But it is not always that criteria are meaningful.

Projectors can be used as part of home theater. Such models are designed to operate when the light is disconnected. Their brightness is not too large, but the color transfer is improved and a very high contrast is supported.

Too bright equipment for darkened places. With ordinary natural illumination, the light flow must be several times more powerful.

Three-page projector devices initially divide white light According to the RGB scheme. Single-size – can only work with one color at the same time. Therefore, the quality of color rendition and brightness suffer greatly. Obviously, the first type guarantees a more decent picture. The image will look natural. Attention should be paid to the level of contrast. It should be noted that adequate data is not always given in the specifications. IMPORTANT: If the projector is bought for brightly lit rooms, you can neglect this parameter. In such a situation, real contrast will depend primarily from the total brightness. But the home theater should be the most contrast.

Sometimes in the descriptions of the projectors, it is mentioned that they are equipped with automatic diaphragms. This is really a useful device, but its effect is manifested only when demonstrating a dark scene, where there will be no bright objects. In a number of specifications, this is indicated as “dynamic contrast”, which often confuses.

ATTENTION: Among the cheapest devices, single-size projectors made using DLP technology give the highest real contrast.

White balance, otherwise named after color temperature, is determined by special techniques that require the use of special equipment. Therefore, it is realistic to evaluate this parameter only by reviews. Direct establishment for an ordinary person is almost impossible. Importance and color coverage. For most purposes that the ordinary consumer puts, the color coverage must comply with the SRGB standard.

But it usually does not arise problems. Still, the SRGB standard has developed quite a long time, and the main part of the projectors is adapted to it. But individual expensive developments go further – they boast an extended color coverage, with increased saturation. Part of the experts believe that the updated standard will work out when the 4K format is approved.

Other recommendations:

  • Choose permission, taking into account your needs and screen forms (for displaying DVDs and business presentations, it is usually enough 800×600);
  • give preference to products with a function of increasing clarity at the same resolution;
  • clarify whether the projector will be put on the table or fixed on the ceiling, on the wall;
  • find out how long it takes installation and preparation for work;
  • check the availability of automatic vertical correction;
  • find out the presence of additional functions and their real value.

Terms of Use

It is usually considered that the installation and adjustment of the film projector is not more difficult than setting up a modern smartphone. But still problems occur periodically and in this area. Experts unambiguously recommend using a wired connection for any possibility. It helps more stable to hold the signal and reduces the risk of minimum. The perfect option is to use a cable suitable for connectors of two devices without adapters. Old projector models may not leave selection – you have to use the VGA standard. In this case, the output of the sound is performed through an additional 3.5 mm connector.

Joining a personal desktop computer is often conducted via DVI cable. Occasionally enjoy them and to connect a projector to a laptop. But if you can apply HDMI even through an adapter, it is better for it and take advantage of. Before connecting both devices, turn off completely. Clamps are twisted if necessary. The projector is turned on earlier than the signal source. Wireless connection is made via Wi-Fi channels or LAN. In low-cost models use external antennas; Modern high-end projectors already have everything you need “on board”.

On computers sometimes you have to install additional software. Recommendation: If there is no network card, or it is inoperable, the Wi-Fi adapter can help. It is worth considering that the projector is not a device for displaying diamers on sheet. It is necessary to use a separate special screen for it. And of course, before doing something, you should look in the instruction.

Fuzziness Pictures or a message about the absence of a signal means that you need to check the screen resolution in the PC settings or laptop. If the computer “does not see” the connected projector, it must be restarted, after checking the quality of the cable connection. If you fail, you will have to configure the output parameters manually. And also it is worth checking and drivers – they often deliver problems with wireless connections.

If the problem is not solved, you need to act according to the instructions, and then contact the service.

In the next video you will find the top 3 short-focused projectors with Aliexpress.

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