Field of view
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.
Gyroscope
The presence in the glasses of its own built-in
gyroscope.
The gyroscope captures the direction, speed, and angle of rotation of the device—usually along all three axes. Without such a sensor, it is impossible to achieve a full-fledged "immersion" in virtual reality, so it is available in all standalone glasses, as well as in most models for PC / consoles (see "Intended use"). In the second case, the only exceptions are individual models with a specific purpose — "personal cinemas", glasses for piloting drones, etc. In turn, glasses for smartphones do not initially require gyroscopes, since smartphones themselves have such sensors. However, there are exceptions here too — advanced models created for specific top-level devices: in them, the built-in gyroscope works in conjunction with the gyroscope of the connected smartphone, ensuring maximum positioning accuracy.
Proximity sensor
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.
Lens distance adjusting
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.
Pupillary distance adjustment
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.
Card reader
The presence of a card reader in the glasses — a device for reading removable memory cards.
Such equipment is found only in independent devices (see "Intended use"). The card reader allows you to install an additional amount of memory to store various data — in addition to your own points drive. At the same time, removable cards have a number of advantages: they are much cheaper than built-in storage (in terms of gigabytes of volume), and the volume of such a card can be chosen at your discretion. So a model with a small capacity, but with a card reader, can be a good alternative to glasses with a large amount of internal memory. Also note that you can purchase several memory cards and change them as needed. And card readers are available in many modern devices (laptops, smartphones, tablets, etc.), so that removable cards make it easier to store information with such devices (for example, you can record a movie on a card for viewing). On the other hand, removable memory is slower than the built-in memory, and some software functions may be limited for it — in particular, not every model of glasses allows you to install applications on the card.
USB C
The presence in the glasses of the connector type
USB-C. This is a relatively new type of USB port, which has a miniature size (slightly larger than microUSB) and a convenient double-sided design that allows you to connect the plug in either direction. It can be found in glasses for various purposes and, accordingly, provide different ways of application. So, in models for PC / consoles, this connector is used similarly to traditional USB — with the main connection, in parallel with the HDMI or DisplayPort video interface. In standalone devices, on the other hand, USB-C is mainly used to charge the battery and connect to a computer for direct file exchange, settings management, firmware updates, etc.
Also note that this paragraph may specify the USB version, which corresponds to the USB-C connector. Nowadays, two versions are relevant — 3.2 gen 1 and 3.2 gen 2; for VR glasses, the difference between them is generally not fundamental.
Headphones
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.
Track camera
The presence of a special external camera in the glasses; often several such cameras are installed at once, for a more complete coverage of the surrounding space.
The main function of the
track camera is to track the movement of game controllers held by the user. This makes it possible to perform various game actions with the help of appropriate hand movements — for example, to strike or shoot from a bow. In addition, the track camera can be used to "perceive" the environment — for example, building a "safe zone" in virtual space based on data on the size of the room, so that the user can see right in the game how far he can move without collisions.