Comparison DJI Goggles RE vs Microsoft HoloLens

The general purpose of the glasses is specified based on which device they are to be used with:

— For PC/Console. Glasses connected during operation to an external device and receiving a video signal from this device. Most often, it is supposed to be connected to a computer or game console, but there are models that can be connected to mobile gadgets, drones, etc. In general, they provide a good compromise between accessibility and functionality, and besides, quite advanced graphics can be displayed on such glasses. On the other hand, for the full use of such models, powerful video cards are often required.

— For a smartphone. Models designed to turn a smartphone into a virtual reality device. To do this, the smartphone is installed in a special slot on the glasses so that its screen is turned towards the user's eyes; glasses themselves do not have screens. And the effect of virtual reality is achieved through the operation of smartphone sensors and (accelerometer, gyroscope) and the use of special applications created specifically for this format of work. The key advantage of glasses of this type is simplicity and low cost: most often these are purely mechanical devices, without built-in electronics (and even advanced models with additional hardware are much cheaper than other types of glasses). On the other hand, the quality of virtual reality directly depends on the capabilities o...f the smartphone, despite the fact that not all devices correctly process such content. In addition, the glasses must be compatible with the smartphone being used, and this is not always guaranteed (for more details, see “Maximum phone size”).

— For quadcopter (FPV goggles). Video glasses used to control drones and radio-controlled unmanned aerial vehicles (UAVs) to provide a first-person view. FPV goggles allow pilots to receive a video feed from a UAV camera in real time. To do this, the design of such glasses provides two separate miniature screens for each eye and complex optics to provide binocular vision. Lenses often have adjustable focal length to suit the visual apparatus and the varying needs of the pilot. Many FPV goggles are equipped with a built-in receiver and antennas to receive signals from the video camera on board the UAV, as well as control the quadcopter. FPV systems are actively used in the segment of racing drones, aerial photography, and even in combat operations. Glasses with a first-person view provide the pilot with a more complete perception of the surrounding environment and improve the controllability of the aircraft.

— Standalone device. Points that function completely autonomously and do not require the use of external devices. To do this, the design provides for its own processor, "RAM", video adapter, drive for storing content and a battery for power. Thus, with such a gadget, virtual reality becomes available literally anywhere in the world; and at a cost, such glasses are comparable to models for PC / consoles. On the other hand, the capabilities of stand-alone devices are noticeably more modest: the relatively low power of video adapters does not allow for the same advanced graphics as on PCs or consoles, the amount of internal memory is usually small, and the continuous operation time is limited by battery charge.

Resolution of built-in displays in glasses equipped with such equipment — that is, models for PC / consoles, as well as standalone devices (see "Intended use").

The higher the resolution, the more smooth and detailed the “picture” is given out by glasses, all other things being equal. Thanks to the development of technology nowadays, models with Full HD (1920x1080) screens and even higher resolutions are not uncommon. On the other hand, this parameter significantly affects the cost of points. In addition, it is worth remembering that in order to fully work with high-resolution displays, you need powerful graphics capable of playing relevant content. In the case of glasses for PCs and set-top boxes, this puts forward corresponding requirements for external devices, and in standalone models you have to use advanced integrated video adapters (which affects the cost even more).

The viewing angle provided by virtual reality glasses is the angular size of the space that falls into the user's field of view. Usually, the characteristics indicate the size of this space horizontally; however, if you need the most accurate information, this point needs to be specified separately.

The wider the viewing angle — the more the game space the user can see without turning his head, the more powerful the immersion effect and the less likely that the image will be subject to the "tunnel vision" effect. On the other hand, making the field of view too wide also does not make sense, given the characteristics of the human eye. In general, a large viewing angle is considered to be an angle of 100° or more. On the other hand, there are models where this indicator is 30° or even less — these are, usually, specific devices (for example, drone piloting glasses and augmented reality glasses), where such characteristics are quite justified given the overall functionality.

The refresh rate supported by the glasses' built-in screens, in simple terms, is the maximum frame rate that the screens are capable of delivering.

Recall that screens are provided in models for PC / consoles and in stand-alone devices (see "Intended use"). And the quality of the picture directly depends on this indicator: other things being equal, a higher frame rate provides a smoother image, without jerks and with good detail in dynamic scenes. The flip side of these benefits is an increase in price.

It is also worth considering that in some cases the actual frame rate will not be limited by the capabilities of the glasses, but by the characteristics of the external device or the properties of the content being played. For example, a relatively weak PC graphics card may not be able to pull out a high frame rate signal, or a certain frame rate may be set in the game and not provide boosting. Therefore, you should not chase after large values and points with a frequency of 90 fps will be enough.

The presence of a sensor in the glasses that reacts to approaching the user's face.

A similar sensor is used to automatically switch between operating and standby modes: for example, when the user takes off the glasses, the sensor turns off the built-in screens (or the phone, if it is connected to the glasses via a connector), saving battery power and equipment life, and when put on, it turns on points for full functionality.

The ability to move the lenses of the glasses back and forth, thus changing their location relative to the screen and the user's eyes. The specific meaning of this function can be different: it can adjust the angle of view (so that the screen fits completely in the field of view and at the same time is not too small), play the role of diopter correction (which is important for users who wear glasses) or focus, change the setting interpupillary distance (see below), etc. These nuances should be clarified separately. However, anyway, this function will not be superfluous — it makes it easier to adjust the glasses to the personal characteristics of the user.

The ability to adjust the interpupillary distance of glasses — that is, the distance between the centers of two lenses. To do this, the lenses are mounted on movable mounts that allow them to be moved to the right / left. The meaning of this feature is that for normal viewing, the centers of the lenses must be opposite the user's pupils — and for different people, the distance between the pupils is also different. Accordingly, this setting will be useful anyway, but it is especially important for users of a large or petite physique, whose interpupillary distance is noticeably different from the average.

At the same time, there is a fairly significant number of glasses that do not have this function. They can be divided into three categories. The first is devices where the lack of adjustment for the interpupillary distance is compensated in one way or another (for example, by a special form of lenses that does not require adjustment). The second is models where this adjustment is not needed in principle (in particular, some augmented reality glasses). And the third — the simplest and cheapest solutions, where additional adjustments were abandoned to reduce the cost.

The presence of your own headphones in the design or delivery of virtual reality glasses.

A full-fledged "immersion" in the virtual world requires not only a picture on the screen, but also an appropriate sound accompaniment, for which headphones are the best option. However, glasses take up quite a lot of space on the head, and not all “ears” can be comfortably combined with them (this is especially noticeable on large over-ear headphones). In addition, when connecting headphones with a wire, there may be problems related to the length and/or location of the audio cable. Thus, some models provide this function. These models can have any purpose (see above); most of these are for PC/console glasses, but headphones are also popular in standalone devices. Also note that some glasses use speakers located in the ear area; such speakers are also considered headphones in this case.

An alternative to the bundled "ears" is a headphone output; however, there are models with both functions at once — either folding / removable cups or the simplest speakers mentioned above play the role of headphones in them.

The type of control provided in the design of the glasses.

Note that in this case we are talking exclusively about our own controls installed directly on the body of the glasses; many models are equipped with external controllers (see "Remote control"), but they are not taken into account in this case.

- Button. Control with classic buttons. The main advantage of this option is simplicity and low cost, while its functionality is quite enough to work with basic functions like menu navigation. On the other hand, the buttons require some effort when pressed, which can be somewhat inconvenient, especially when using the controls intensively. However, most often this disadvantage is still not fundamental.

- Touch. Control using sensors that are sensitive to touch and do not require pressing (unlike buttons). In the simplest models, these are separate sensors, the functions of which are similar to the same buttons. In more advanced devices, entire touch panels can be provided, for example, allowing you to control the cursor visible through the glasses and use special gestures. Anyway, this type of control is more advanced than push-button, however, it is more expensive, and therefore less common.