Comparison Visuo XS809S vs DJI Tello

General drone specialization.

This parameter is specified in cases where the device has a clearly defined specialization and is noticeably different in equipment/functionality from conventional quadcopters for entertainment purposes. In our time, the following types of drones are distinguished: mini-drones, racing vehicles(including in the form of racing mini-drones), selfie drones, kits for battles, as well as industrial/commercial solutions. Here are the features of each of these options:

— FPV drones. Quadcopters with a “First Person View” transmit the image visible to the camera in real time. Those. During such a broadcast, the operator will see on the screen the same thing that directly falls into the field of view of the lens. This can be useful for photo and video shooting from the air, more precise control of a drone, and performing a number of specific tasks for reconnaissance or military purposes. Smartphones, tablets or other similar gadgets are used to view images from the camera; there are also remote controls with built-in screens (see “Display for FPV broadcast”) and specialized masks like virtual reality glasses (see “Helmet for FPV broadcast”).

— Mini-drone. Miniature devices with dimensions of no more than 150 mm (length a...nd width) and a weight of no more than 100 g. This allows them to be easily transported from place to place, as well as to fly even in confined spaces - right up to city apartments. At the same time, many mini-drones are intended exclusively for entertainment, but there are also models with quite advanced characteristics. But the communication range of such equipment, as a rule, is quite limited (although, again, exceptions are possible); the same applies to carrying capacity.

- Racing. Devices originally created for drone racing. Such races require not only fast completion of the tracks, but also the ability to accurately fit into a given trajectory; Therefore, racing quadcopters differ not only in speed, but also in control accuracy. In addition, among such machines there may be modifications for complex aerobatics (freestyle, 3D) - in their characteristics the emphasis is even more shifted to accuracy and responsiveness. It should be borne in mind that most racing models are not only expensive, but also quite difficult to operate and are designed for experienced pilots; so it hardly makes sense to buy such a device for initial training or entertainment use.

— Racing mini-drone. A variation of the racing machines described above, characterized by reduced dimensions and having corresponding features. On the one hand, these features include ease of transportation and the ability to be used in confined spaces, on the other hand, relatively low load capacity and communication range.

— Selfie drone. Copters designed primarily for taking selfies. Among the main features of this technology are its small dimensions and the absence of a classic remote control: control is carried out either via a smartphone or using gestures through a special compact controller. This format of work eliminates the need to carry a bulky remote control and allows the operator to look natural in the frame - posing for a photo, rather than being distracted by controlling the drone. And some advanced models provide additional functions that make shooting even more convenient: face detection with autofocus and auto-centering, Follow Me mode (see “Flight Modes”), etc.

— Industrial/commercial. High-quality copters designed for professional use: photographing and video shooting from high altitudes in high resolution, “inspecting” industrial facilities and land plots, spraying fields, etc. In addition to their large dimensions, they are distinguished by a long range and flight altitude (and even and others are usually calculated in kilometers), high carrying capacity and extensive functionality. Thus, many models allow the installation of heavy advanced cameras (some are even initially designed for certain models of professional cameras), others have built-in “optics” with advanced capabilities (for example, with a high magnification factor or support for shooting in the IR range). The design usually includes a large abundance of sensors. And some models may have more specific functions - for example, detecting other aircraft nearby. Of course, such functionality is not cheap.

— Combat (battle kits). Drones designed to organize air battles. As a rule, they are sold in sets of two cars - so that the fight can be organized immediately, without purchasing anything additional; and most models allow you to organize group battles (at least “all against all”) - for this it is enough to buy several identical sets. The role of the “gun” in such a copter is usually played by an IR emitter, and hits are recorded using appropriate sensors. For control, a smartphone or other gadget is usually used, and the control application can provide very interesting and unusual functions - for example, statistics for each player with experience points received for battles, as well as special “skills” (temporary invulnerability, unusual maneuver, etc.) . p.), purchased for these points and activated by clicking on the corresponding icon in the application.

Maximum flight time of a quadcopter on one full battery charge. This indicator is quite approximate, since it is most often indicated for ideal conditions - in real use, the flight time may be less than stated. However, by this indicator it is quite possible to evaluate the general capabilities of the copter and compare it with other models - a longer declared flight time in practice usually means higher autonomy.

Note that for modern copters, a flight time of 20 minutes or more is considered a good indicator, and in the most “long-lasting” models it can exceed 40 minutes.

The highest speed that a quadcopter can achieve in horizontal flight. It is worth considering that in most cases this parameter is indicated for optimal operating conditions: a fully charged battery, low air temperature, minimum weight, etc. However, it is quite possible to rely on it both when choosing and when comparing different models of copters with each other.

Note that quadcopters were originally designed as stable and maneuverable aerial platforms, and not as high-speed vehicles. Therefore, you should specifically look for a fast quadcopter only in cases where the ability to quickly move from place to place is critical (for example, when the device is supposed to be used for video recording of fast-moving objects over large areas).

Resolution of the matrix in the standard camera of the quadrocopter.

Theoretically, the higher the resolution, the sharper, more detailed image the camera can produce. However, in practice, the quality of the "picture" is highly dependent on a number of other technical features - the size of the matrix, image processing algorithms, optical properties, etc. Moreover, when increasing the resolution without increasing the size of the matrix, the image quality may drop, because. significantly increases the likelihood of noise and extraneous artifacts. And for shooting video, a large number of megapixels is not required at all: for example, to shoot Full HD (1920x1080) video, which is considered a very solid format for quadrocopters, a sensor of only 2.07 megapixels is enough.

Note that high resolution is often a sign of an advanced camera with high image quality. However, this quality is not determined by the number of megapixels, but by the characteristics of the camera and the special technologies used in it. Therefore, when choosing a quadcopter with a camera, you should look not so much at the resolution as at the class and price category of the model as a whole.

The maximum resolution and frame rate supported by the aircraft camera when shooting in HD (720p).

HD 720p is the first high-definition video standard. Notably inferior to Full HD and 4K formats in terms of performance, it nevertheless provides pretty good detail without significant demands on the camera and processing power. Therefore, HD support is found even in relatively inexpensive copters. And in high-end models, it can be provided as an addition to more advanced standards.

In drones, HD cameras typically use the classic 1280x720 resolution; other, more specific options are practically non-existent. As for the frame rate, the higher it is, the smoother the video turns out, the less movement is blurred in the frame. In general, values up to 24 fps can be called minimal, from 24 to 30 fps — medium, from 30 to 60 fps — high, and speeds over 60 fps are used mainly for slow motion HD.

The viewing angle provided by the standard quadcopter camera; for optics with adjustable zoom, usually, the maximum value is taken into account.

The viewing angle is the angle between the lines connecting the centre of the lens to the two opposite extreme points of the visible image. Usually measured along the diagonal of the frame, but there may be exceptions. As for the specific values of this parameter, in modern copters they can range from 55 – 60 ° to 180 ° and even more. At the same time, a wider angle (ceteris paribus) allows you to simultaneously fit more space into the frame; and a narrower one covers a smaller space, however, the objects that are in the frame look larger, it is easier to see individual small details on them. So when choosing by this parameter, you should consider what is more important for you: wide coverage or an additional zoom effect.

Stabilization system built directly into the complete drone camera.

Any stabilization system is designed to compensate for vibrations and shakes, thus providing a stable image, without shaking or sudden movements in the camera. This function slightly increases the cost of the device, but the video quality increases noticeably. On the other hand, stabilization makes it difficult to perform complex maneuvers, since its use worsens the feedback: changes in the camera image do not quite correspond to changes in the drone’s position in space. In light of this, in devices that have an acrobatic mode (see “Flight Modes”), such a system can be switched off.

Note that specifically in the camera, stabilization is most often carried out according to the electronic principle: reserve space is allocated at the edges of the matrix, and in the event of vibrations or shocks, the camera “pulls up” a fragment of the image from this reserve, keeping the image in the frame motionless. This format of operation somewhat reduces the useful area of the matrix, but is inexpensive, does not affect the weight of the camera and does not complicate its design. A more effective, but also more complex and expensive option is a built-in optical stabilizer, which uses a lens with a moving lens system.

In addition, another method can be used to stabilize the image - a mechanical gimbal stabilizer. However, such a gimbal is not part of the c...amera, so its presence is specified separately (see below). At the same time, some copters provide both functions at once - both built-in stabilization and gimbal; this ensures maximum efficiency.

The presence of a slot for memory cards in the design of the quadcopter.

Usually, this function is provided in models equipped with cameras (see “Camera type”), and the cards themselves are used primarily for recording captured photos and videos. However, in some models, other data can be stored on such media — GPS tracks, flight routes, flight programs, etc. Anyway, cards are convenient, first of all, by the ability to quickly transfer data between the device and other devices that have a card reader (in particular, laptops).

It is worth noting that different devices can be designed for different standards of memory cards, and the media themselves are usually not supplied in the kit. Therefore, before choosing a card, you should clarify according to official data which type will be optimal for your model.

— Return home function. With this function, the quadcopter can automatically return to the starting point. The specific details of this feature may vary. So, some models return "home" at the user's command, others are able to do it on their own — for example, when the signal from the remote control is lost or when the battery charge is critically low; in many devices, both options are provided at once. Also note that this function is found even in models that do not have a GPS module (see "Sensors") — the copter can navigate in space in another way (by inertial sensors, by a signal from the remote control, etc.).

— Follow me mode. A mode that allows the quadcopter to constantly follow the user at a short distance — like a "personal drone". The way to implement this mode and the equipment required for it can be different: some models track the direction to the transmitter and the signal strength from it, others constantly receive data from the GPS module of a smartphone or other gadget and follow these coordinates, etc. Anyway, such a mode can be useful not only for entertainment, but also for quite practical purposes — for example, for using a quadcopter as an “air chamber”, constantly located next to the operator and at the same time not occupying hands.

— Dronie (distance). Initially, the term “dronie” refers to a selfie (photo or video) taken from a...drone. This mode is mainly intended for such tasks. And its essence lies in the fact that the copter smoothly moves away from a certain object along a given trajectory, keeping this object in the centre of the frame. The classic version of flying in Dronie mode is moving away first horizontally, then horizontally and up; however, in some models, the copter’s trajectory can be further configured. Frame management can also be carried out in different ways — from simple pointing at a certain point and ending with the selection of an object on the screen with further "smart" tracking of this object. Anyway, for all its simplicity, such a shooting technique allows you to create quite interesting videos: for example, in this way you can first capture a group of people in close-up in one video, then the beauty of the landscape around them.

— Rocket (distance up). A flight mode in which the copter smoothly rises to a predetermined altitude along a strictly vertical trajectory. Similar to the Dronie described above, it is mainly used when shooting video: first, a certain scene is shot in close-up, and as it rises, the camera covers an increasingly wider area around this scene. Usually, in Rocket mode, you can pre-set the height at which the device will stop.

— "Orbit mode" (flying in a circle). A mode that allows you to launch the copter in a circular orbit around the specified point. It is also used mainly for shooting video: in such cases, the camera remains constantly pointed at a given object, but the angle and background, due to the movement of the drone, are constantly changing. In the "orbit" settings, usually, you can set its radius, height and direction of movement, as well as the angle of the camera.

— Helix (circle in a spiral). Another mode used as an artistic technique for filming videos. In this mode, the copter, keeping a given object in the centre of the frame, moves around it in a spiral, gradually moving away and increasing its height. This allows you to get the maximum variety of angles and angles of coverage.

Note that Dronie, Rocket, Helix, and Orbit modes originally appeared as part of the proprietary QuickShot toolkit in DJI's Mavic series drones. However, later similar functions were introduced by other manufacturers, so now these names are used as common nouns.

— Flight plan(Waypoints). The ability to set a specific flight route for the quadcopter, by control points. This feature is very similar to the GPS waypoint flyby (see above), but it works differently, without the use of GPS navigation. One of the most popular options is building a route in the smartphone application through which the copter is controlled; when the programme is launched, the smartphone issues a sequence of commands corresponding to the route to the device. In general, the Waypoints mode is not as accurate as a GPS waypoint flyby and offers fewer options. Therefore, this function is mainly for entertainment purposes; if the copter has a camera, it can be useful for taking a selfie or a simple video.

— Flight by GPS points. A mode that allows you to launch a quadcopter along a specific route — by setting individual route points to the car in advance (according to GPS coordinates) and the order in which they are passed. In addition, additional settings may be provided — for example, speed and altitude on individual sections of the route. This function is similar to the Waypoints mode (see below) in many ways, but it is found mainly in mid-range and high-end devices. At the same time, the use of GPS provides higher accuracy, which allows the drone to be used for professional purposes. For example, if you set a route for shooting from the air in this way, the operator will be able to fully concentrate on working with the camera, without being distracted by controlling the copter.

— Acrobatic mode. A special mode for performing aerobatics. Note that the specific meaning of this mode may be different, depending on the level and purpose of the copter. So, in the simplest entertainment models, automatic programs are usually provided that allow you to perform certain aerobatic manoeuvres literally “at the touch of a button”. And in advanced devices in flight mode, the stabilization system is turned off, and the drone is very sensitive to operator commands; this requires high precision in control, but gives maximum control over the flight.