Comparison Optoma UHD550X vs Optoma UHD60

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.

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 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.

— Light sensor. A sensor that detects the level of ambient light. Most commonly used to automatically adjust the brightness of the projector to suit current conditions. So, in a darkened room, high brightness is not needed, but in daylight, on the contrary, you cannot do without it. You can also adjust the operating mode manually, but it is more convenient when the projector does it automatically.

— DLNA support. DLNA technology is designed to connect home electronics into a single network and exchange content in real time. One of its advantages is that DLNA devices are guaranteed to be compatible with each other regardless of model and manufacturer. In a projector, this feature can be used, for example, to view a movie on a large screen from a computer hard drive, or to display an Internet broadcast on this screen that was originally opened on a tablet. DLNA works on the basis of a standard local network, with a connection via LAN (see "Management ports") or Wi-Fi (see below).

— MHL support. The projector has HDMI inputs that support the MHL standard. This standard is used to transfer video and audio from mobile gadgets (via microUSB) to external devices. Accordingly, this feature is useful for those who plan to connect smartphones and other portable equipment to the projector. At the same time, an MHL gadget connected t...o a compatible HDMI port can also be charged in the process. Note that you can also output the MHL signal to a regular HDMI port, but this will require an adapter, and the charging function will not be available.

— Picture-in-picture. Ability to play two channels simultaneously on one screen: main and additional (in a separate small window). The sound is played only for the main channel. This mode allows, for example, to skip a break in a football match and not be late for the second half. Note that for this function to work, images must come from different sources — for example, from two different tuners, or from a tuner and an external device (DVD player, media centre, etc.).

— PJ-Link protocol. The projector supports the PJ-Link protocol. This is a service standard designed to control projectors over local networks (usually LAN or HDBaseT, see "Management port"). All PJ-Link-enabled equipment (projectors, controllers) is fully interoperable regardless of brand and manufacturer, making it much easier to build networks of multiple projectors and replace individual components in such networks.

— 3D support. Support for 3D implies the ability to reproduce three-dimensional stereoscopic images. A 3D image can be based on various technologies. Traditionally, active (see the relevant paragraph), passive (see the relevant paragraph) and hybrid 3D technologies are distinguished. Special glasses are required to view the three-dimensional image. In the case of active 3D, special shutters are built into the glasses, which operate from an independent power source. For passive and hybrid 3D, regular 3D glasses without battery power are sufficient.

— Active 3D. Active 3D technology is based on the principle of alternating flickering of the image. The flickering of the image on the screen is synchronized with the flickering of the lenses in the glasses, as a result, each eye receives a separate image, which makes the picture three-dimensional. The main advantage of active 3D is the ability to view images without reducing the original picture quality. You can look at the screen from any angle and from any position, while the image will still be three-dimensional. Among the shortcomings, there is the presence of some discomfort for the eyes, which occurs due to the regular flickering of lenses in glasses. Also, active 3D glasses may darken the original brightness of the image somewhat. Additionally, glasses of this type are very expensive.

— Passive 3D. Passive 3D provides the display of a double image. Passive 3D glasses use special lenses that cut off the duplicate image in such a way that each eye sees only the image intended for it, which creates the illusion of a three-dimensional image. The main advantage of passive 3D is that it does not tyre the eyes, which is typical for active flickering 3D. Passive 3D glasses are inexpensive.

— Interactive pen. The projector supports interactive pen technology. This technology allows you to actually turn the projected image into an interactive whiteboard: with a pen, you can draw, write and make notes directly on the projected image, which is especially useful during presentations and educational events. It is worth taking into account that the pens themselves and additional equipment for their work may not be included in the set.

— Multimedia (air mouse remote). Air mouse remote are devices that have a gyroscope, which allows you not only to switch menu items with the “↑”, “↓” buttons, but to use the remote control as a mouse. By directing it to the screen, a cursor will appear that moves in the direction of the remote control. This makes management easier and faster.

— Voice control. The projector's support for voice control allows you to dictate certain commands through the remote control. However, voice control does not cover all functions and recognition accuracy may require re-entering the command. If you need a more extensive range of functions, then pay attention to the voice assistant.

— Voice assistant. For a long time now, device control has been shifting to voice commands. For this, certain interfaces and systems are used. The most popular are Amazon Alexa and Google Assistant. For "apple" devices, this is Apple Siri, but this technique is not presented in projectors. At the same time, unlike the voice control function, the voice assistant does not just turn on this or that function, mode, makes it louder, quieter, but allows you to perform certain operations in applications, whether it is to launch the desired clip on Youtube or display the weather in the browser.

The number of USB 2.0 ports provided by the projector.

Do not confuse these connectors with USB slave (see "Management ports") — in this case we are talking about USB ports for various peripherals. Most often, these ports are used for direct playback of content from flash drives and other storages (for example, external HDDs). At the same time, we note that video viewing is not available in some projectors (only photos), in others a very limited set of formats may be supported. However, a direct connection is often more convenient than viewing through a computer or other device. The USB ports can also be used for other purposes, such as updating firmware, transferring files between a flash drive and the projector's built-in storage, or even for keyboards/mouses (in Android devices, see above).

The USB 2.0 standard itself is considered obsolete, but it is quite enough for projectors, and newer peripherals are fully compatible with such connectors. At the same time, you rarely have to connect more than one external device to the projector at a time, so there are few models with more than one USB 2.0.

HDMI interface version supported by the projector.

About the interface itself, see above, and its different versions differ in maximum resolution and other features:

— v 1.4. The version released back in 2009. Despite this, it has quite decent specifications, due to which it continues to be used in modern video equipment. Specific features of HDMI v1.4 include 3D support, the ability to work with 4K video (4096x2160) at 24 fps and with Full HD at 120 fps. In addition to the original version, there are also improved modifications — v.1.4a and v.1.4b; they differ only in some 3D-related improvements.

– v 2.0. Standard introduced in 2014. Thanks to the increased bandwidth compared to v 1.4, it allows you to transfer 4K video at speeds up to 60 fps, as well as up to 32 channels and up to 4 audio streams simultaneously. In addition, this version was the first to introduce support for the 21:9 ultra-wide format, and the v2.0a update introduced HDR compatibility, with further enhancements to this feature in version 2.0b.

— v 2.1. A version released in 2017 also known as HDMI Ultra High Speed. The data transfer rate has indeed been significantly increased, allowing the support for video up to 10K at 120 frames per second. In addition, some improvements regarding HDR have been made. Note that connecting via HDMI v2.1 requires the use of special cables, although the basic features remain available when working with standard cables.

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.