Comparison Epson EB-U42 vs Epson EB-W41

Main purpose of the projector.

This parameter is somewhat subjective and largely depends on how the device is positioned by the manufacturer; nevertheless, for the most comfortable use, it is best to follow the stated purpose. The options may include: universal, for presentations, for home theater, professional, portable, gaming. Here is a more detailed description of each option:

— Universal. The simplest type of projector, roughly speaking—any model that does not belong to one of the specializations described below. Most have fixed optics, a projection distance of 1 – 12 m, an image diagonal of approximately 1 – 7 m (see below), and a relatively low price.

— For presentations. Projectors primarily intended for business use, particularly for giving presentations. They generally have a short projection distance with a fairly large image diagonal, allowing them to be used in small rooms; they can work with both widescreen and standard image formats (see below), and support resolutions typical of computer graphics cards—for example, 1280х800. At the same time, the native resolution itself (see below) may be quite low. In addition, an almost mandatory feature of this type of projector—with rare exceptions—is a 15-pin D-Sub...input (see “Connectors”).

— For home theater. Projectors intended primarily for watching films. The main criterion for assigning a particular model to this category is how the projector is positioned by the manufacturer itself (in other words, whether this purpose is specified in the official documentation). However, there are also some common features: cinema-oriented models generally support widescreen image formats, have a high native resolution (see below), allowing them to work with HD video, and are equipped with the appropriate interfaces (see “Connectors”).

— Professional. High-end projectors with advanced specifications, numerous features and, accordingly, a considerable price. They are characterized by high image contrast ratios, support high-resolution video (including cinematic image formats), feature optical zoom for scaling the image without loss of quality, allow the connection of multichannel audio systems, and much more. The specific set of options in professional projectors may vary depending on the model, but in any case, these are fully loaded devices with top-tier specifications.

— Portable projector. An ultra-compact type of projector: most models are small enough to be carried in a pocket. These devices are primarily intended for giving impromptu presentations. Their form factor and power supply can vary. Some models are standalone devices with their own built-in storage and batteries (and sometimes even a full-fledged mobile OS such as Android on board). Others are designed like external cases or add-ons and, when in use, are attached directly to a mobile phone, using it as the signal and power source. However, in all cases, portable projectors have rather modest specifications due to their small size—for example, they have neither high brightness nor high image contrast. Battery life (in models with their own batteries) generally ranges from 40 minutes to an hour and a half. Energy-efficient LED lamps are also characteristic of this type (see below).

— Gaming. Specialized projectors intended for use with video games. Externally, they often feature a distinctive “aggressive” design, which may follow the style of a particular line of gaming PCs or laptops. As the name suggests, their practical specifications are primarily geared toward delivering a high-quality gaming image. To this end, projectors for this purpose typically offer, among other things, high native resolution (at least 1920х720, and more often 1920х1080 or higher), color reproduction of 1 billion colors, support for refresh rates (see below) of up to 120 Hz inclusive, and at least one HDMI input for receiving a digital signal from a computer graphics card. In addition, such models often support 3D. The maximum image diagonal may reach 7.5 m or more; this category also includes ultra-wide-angle devices capable of providing an image diagonal of about 3 m from a distance of about half a meter.

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.

The native resolution of the image produced by the projector matrix.

The minimum for modern projectors is actually the VGA standard, which assumes a resolution of 800x600 or close to it. The most limited of modern high-definition standards is HD (720); the classic size of such a frame is 1280x720, but projectors also have other options (up to 1920x720). A more advanced HD format is Full HD (1080), which also has several variations (the most popular is 1920x1080). And among high-end projectors there are models of Quad HD, Ultra HD (4K) and even Ultra HD (8K) standards.

In general, the higher the resolution, the clearer and more detailed image the projector can produce. On the other hand, this indicator directly affects the cost, and all the benefits of high resolution can only be appreciated if the reproduced content also corresponds to it. Note that modern projectors can work with higher resolutions than the “native” ones – for more details, see “Maximum 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.

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.

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.

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.

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.

Optical zoom ratio provided by the projector.

Optical image enlargement is achieved through the operation of the lenses in the projector’s lens. With this type of magnification, the size of the entire image changes; this can be useful both for adjusting the picture to the screen size and for detailed viewing of individual details (provided that these details do not extend beyond the screen when enlarged). In general, optical zoom is considered more advanced than digital zoom, since it allows you to adjust the diagonal without moving the projector and preserves the original image resolution regardless of the zoom ratio. However, lenses with this capability (“zoom lenses”) are more complex and expensive than fixed optics, although the price difference is practically unnoticeable compared with the cost of the projectors themselves.