Comparison Hubsan X4 H107C Cam HD vs Hubsan X4 H107D FPV Plus

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.

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 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.

The capacity of the battery supplied with the quadcopter.

Theoretically, a larger battery can provide a longer charge time. However, keep in mind that this time also depends on the power consumption of the copter — and it is determined by the power of the engines, dimensions and weight, as well as a number of other features. In addition, the actual battery capacity is determined not only by ampere-hours, but also by its nominal voltage. Therefore, only quadcopters with the same battery voltage and similar operating characteristics can be compared by amp-hours; and it is best to evaluate battery life by directly claimed flight time (see below).

The term "protected housing" in drone copters usually refers to protection for propellers; sometimes it also covers the fuselage, but the key point is precisely the covered blades.

The specific design of such protection may be different. The traditional option is characteristic rings or arcs that cover each screw of the copter on the sides; however, there are also more exotic options — for example, a lattice "shell" that covers the entire apparatus. Anyway, in the event of a collision, the protective devices prevent the rotating blades from contacting the obstacle, protecting both the propellers themselves and the objects surrounding the copter from damage; of course, such protection is not absolute, but at least it reduces the likelihood of serious accidents. And solid rings around the screws can also increase their traction. On the other hand, the additional "kit" increases air resistance, especially when driving at high speed; therefore, in many drones (especially advanced ones), protection is made removable — primarily for flights in open areas, where there are no obstacles and the risk of collisions is minimal.

General dimensions of the device. A fairly obvious parameter; we only note that for models with a folding structure (see above), in this paragraph, the dimensions in the working (unfolded) position are given, and the dimensions in the folded form are specified separately.