Comparison Viewsonic PX701HD vs Viewsonic PX706HD

The main function of the projector.

This parameter is rather conditional, it largely depends on how the device is positioned by the manufacturer; however, for the most comfortable use, it is best to follow exactly the stated purpose. The options here can be: multipurpose, for presentations, for home theater, professional, portable, gaming. Here is a more detailed description of each option:

— Multipurpose. The simplest kind of projectors, roughly speaking – all models that do not belong to any of the specializations described below. Most of them have non-interchangeable optics, a throw distance of 1-12 m, an image diagonal of about 1-7 m (see below), and a relatively low cost.

— For presentations. Projectors designed primarily for business use, such as presentations. Usually they have a small throw distance with a rather large diagonal, which allows them to be used in small rooms; capable of working with both widescreen and conventional image formats (see below), and also support resolutions typical for computer graphics cards — for example, 1280x800. In this case, the actual resolution itself (see below) can be quite low. In addition, an almost mandatory feature of this type of projectors (with a few exceptions) is the presence of a D-Sub 15 pin input (see "Connectors").

— For home theater. Projectors designed primarily for film viewing. The main criterion for classifying a particular model in this category is how the projector is positioned by the manufacturer itself (in other words, whether this purpose is indicated in the official documentation). However, there are some common features: cinematographic models usually support widescreen image formats, have a high real resolution (see below) that allows you to work with HD video, and are also equipped with the appropriate interfaces (see "Connectors").

— Professional. High-quality projectors with advanced parameters, an abundance of functions and, accordingly, a considerable price. They are characterized by high image contrast, support high-resolution video (including cinematic image formats), have optical zoom to scale the image without losing quality, provide the connection of multi-channel sound systems, and much more. The specific set of options in professional projectors may vary depending on the model, but in any case, these are the most charged devices with top-end characteristics.

— Portable projector. An ultra-compact variety of projectors: most models are pocket-sized. Such devices are intended primarily for improvised presentations. The format of work and power supply may be different. So, some models are made as separate devices with their own built-in storages and batteries (and sometimes even with a full-fledged mobile OS like Android on board). Others are similar in design to external cases or consoles and are put directly on the mobile phone during operation, using it as a source of signal and power. However, anyway, portable projectors, due to their small size, have rather low technical specifications — they have neither brightness nor high image contrast.. Battery life (in models with their own batteries) usually ranges from 40 minutes to one and a half hours. Also, this variety is characterized by cost-effective LED lamps (see below).

— Gaming. Specialized projectors designed for use in video games. Outwardly, they are often distinguished by a characteristic “aggressive” design, while the design can be done in the style of a certain line of gaming PCs or laptops. As for the specifications, they, in accordance with the name, are aimed primarily at providing a high-quality game "picture". To do this, projectors for this purpose provide, in particular, high real resolution (not lower than 1920x720, and more often 1920x1080 or more), colour reproduction at the level of 1 billion colours, support for frame rate (see below) up to 120 Hz, and also at least one HDMI input for receiving a digital signal from a computer graphics card. In addition, such models often provide support for 3D. The maximum image diagonal can reach 7.5 m or more; at the same time, ultra-wide-angle devices are also found in this category, capable of providing an image diagonal of about 3 m from a distance of about half a metre.

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.

Minimum projector lamp life as stated by the manufacturer. Specified by the total time of continuous operation. Note that if the projector was operated without violations, then upon reaching this time, the lamp will not necessarily fail — on the contrary, it can work for quite a long time. However, when evaluating durability, it is best to focus on the claimed service life.

When working in economy mode, the brightness of the backlight is noticeably reduced, on average by 30-50%. With a decrease in brightness, heat dissipation also decreases, which saves the working life of the illuminator, thereby increasing the lamp life. Thus, the ECO mode allows you to extend the lamp life by an average of 30%. If the typical projector lamp life is 4000 hours, regular use of the ECO mode will extend the backlight life to approximately 5500 hours.

The power consumption of the backlight lamp installed in the projector.

Theoretically, the more powerful the lamp, the brighter it is. However, this is only true when comparing lamps of the same type (see above); and even in this case, the brightness may also depend on the nuances of the design. Therefore, when evaluating the capabilities of a lamp, it is worth focus not so much on power, but on the directly claimed brightness in lumens (see below).

But what this parameter directly affects is the total power consumption of the projector: the lamp is the most “greedy” component of the device, compared to it, the power consumption of the rest of the electronics is very small. Also note that many powerful lamps have high heat dissipation and require cooling systems, which affects the size and weight of the projector.

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 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.