Comparison Hubsan X4 H502E Desire Cam vs Hubsan X4 H502S Desire FPV

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).

Possibility of online video broadcasting from the quadcopter to an external device — smartphone, laptop, control panel with display, virtual reality glasses, etc.

This feature provides several benefits at once. Firstly, it greatly simplifies the control of the device, even if it is within sight; and if the copter is not visible from the ground (which happens often, especially when using heavy professional equipment), then it is very difficult to do without "eyes on board". Secondly, live broadcasting makes it possible to use a drone for real-time observations, as well as full-fledged aerial photo and video shooting; recording of footage can be carried out both on an external device that receives the broadcast, and on the aircraft’s own carrier (usually a memory card — see below).

The specific features of the live broadcast for each model should be clarified separately; however, nowadays, thanks to the development of technology, such an opportunity is available even in low-cost devices.

— 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.

Additional sensors provided in the design of the quadcopter.

— Heights. A sensor that determines the flight altitude of the machine. Such sensors can use the barometric or ultrasonic principle of operation. In the first case, the height is measured by the difference in atmospheric pressure between the current point and the starting point (that is, the sensor determines the height relative to the initial level); in the second, the sensor acts similarly to sonar, sending a signal to the ground and measuring the time it takes to return. Barometric sensors are not very accurate, but they work well at high altitudes — tens and hundreds of metres; ultrasonic — on the contrary, they allow you to accurately manoeuvre at low level flight, but lose effectiveness as you climb. However, in some advanced models, both options may be provided at once. Data from the height sensor can either be used by the quadcopter “independently” (for example, when hovering or automatically returning), or transmitted to the operator to the remote control or smartphone.

— Optical. A sensor that allows the quadcopter to "see" the environment in certain directions. One of the simplest variants of such a sensor is a downward-facing camera that allows the device to “copy” the surface under which it flies. Due to this, the machine, for example, can navigate indoors, where the signal from GPS satellites does not reach. In...addition to such a chamber, "eyes" can also be provided from different sides of the machine. Note that optical sensors have certain limitations in their use — for example, they lose their effectiveness on dark, shiny or uniform (without noticeable details) surfaces, as well as at high speeds.

— GPS module. A sensor that receives signals from navigation satellites (GPS, in some models also GLONASS) and determines the current geographical coordinates of the machine. Specific ways of using position data can be different: returning home, flying by waypoints (see below), recording a flight route, etc.

— Gyroscope. A sensor that determines the direction, angle and speed of the machine's rotation along a specific axis. Modern technologies make it possible to create full-fledged three-axis gyroscopes of very compact dimensions, and it is with such modules that quadcopters are usually equipped. On the basis of gyroscopes, automatic stabilization systems usually work, returning the car to a horizontal position after a gust of wind, collision with an obstacle, etc. At the same time, such equipment affects the cost of the device, and in some cases (for example, during piloting), automatic stabilization is more of a hindrance than a useful feature. Therefore, some low-cost, as well as advanced aerobatic quadcopters, are not equipped with gyroscopes.

The range of the drone is the maximum distance from the control device at which a stable connection is maintained and the device remains controlled. For models that allow operation both from the remote control and from a smartphone (see "Control"), this item indicates the maximum value — usually achieved when using the remote control.

When choosing according to this indicator, note that the range is indicated for perfect conditions — within line of sight, without obstacles in the signal path and interference on the air. In reality, the control range may be somewhat lower; and when using a smartphone, it will also depend on the characteristics of a particular gadget. As for specific figures, they can vary from several tens of metres in low-cost models to 5 km or more in high-end equipment. At the same time, it should be said that the greater the range of communication, the higher its reliability in general, the better the control works with an abundance of interference and obstacles. Therefore, a powerful transmitter can be useful not only for long distances, but also for difficult conditions.

The presence of an information display on the quadcopter control panel.

Note that this feature should not be confused with the FPV broadcast screen (see below). The information display is usually a simple segment display capable of displaying numbers, individual letters, and, on some models, a limited set of special icons. However, even such equipment significantly expands the capabilities of the remote control and allows the operator to receive a lot of additional information: battery charge, signal level, range, flight altitude, etc. At the same time, the auxiliary screen is inexpensive and can be used even in low-cost models. And in advanced drones, it may well complement the broadcast display: separating data into different screens contributes to ease of control.

A special display that can display the image from the drone's camera in the live broadcast (FPV) mode.

The display for FPV broadcasting is usually placed on the remote control: this allows you to view the image from the camera without being distracted from the control. At the same time, the specific design of such a screen may be different: in some models it is built directly into the remote control, in others it is placed on a special mount and can be removed (or even work separately from the remote control). However, anyway, this feature means that viewing live broadcasts from the copter is available in the original configuration, for this you do not need to look for additional devices such as smartphones or tablets.

An alternative to the display in some drones is an FPV broadcast helmet. It has its advantages (see below), but the traditional screen is cheaper, moreover, it is easier and more versatile to use: so, it can be viewed without problems even with glasses, and the image can be seen by several people.

The number and type of batteries used in the quadcopter control panel.

— AA. Replaceable batteries, colloquially known as "AA batteries". They are available not only in the form of disposable batteries, but also in the form of rechargeable batteries, are produced under various brands that differ in price and quality (which provides freedom of choice), and finding such elements on the market is usually not a problem. The power and capacity of AA elements are relatively small, but in most cases they are quite enough for normal operation of the transmitter for quite a long time. Usually, modern consoles require several of these batteries; in the most high consumption this number can reach 8.

— AAA. Also known as "pinky". In fact, a smaller version of popular AA elements (see above); has the same key features, but differs in more compact dimensions and, as a result, somewhat reduced power. This option is typical for low-cost class models, with a small range of the remote control.

— 3s. This marking does not describe the size of the battery, but its operating voltage and technology. It denotes a lithium-ion or lithium-polymer battery (see "Battery type"), assembled from three cells with a standard voltage of 3.7 V each, and thereby delivering an operating voltage of 11.1 V. The advantages of such a power supply are high power and capacity, which allows you to use the remote control for a long time without recharging. At the same time, batteries of thi...s type can vary significantly in size and weight, and not every model marked 3s will be compatible with the remote control. In addition, finding a spare battery is more difficult than a set of cells of a standard size.

— Proprietary battery. Powered by an original battery that is not related to any of the options described above. Such batteries can be much more powerful than replacement cells, making them well suited even for remotes with high power consumption. Their main advantage is the difficulty with quick replacement: the design of the remote control is at best poorly suited for this, and at worst the battery is generally non-removable. Also, finding the right replacement battery can be a major hassle.

The diameter of each individual quadcopter/multicopter propeller (it is usually the same for all propellers). In general, this indicator is of secondary importance: it is selected by the manufacturer in such a way as to provide features corresponding to the class of the machine. We only note that the noise level may depend on the size of the propellers: all other things being equal (the number of propellers, the number of blades, the weight of the apparatus, etc.), a propeller of a smaller diameter must rotate faster to provide the necessary thrust, and at high speeds the engines also run louder.