Comparison JJRC H73 vs MJX X103W

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 maximum resolution and frame rate supported by the aircraft camera when shooting in Full HD (1080p).

The traditional resolution of such a video is 1920x1080; this is what is most often used in drones, although occasionally there are more specific options — for example, 1280x1080. In general, this is far from the most advanced, but more than a decent high-definition video standard, such an image gives sufficient detail for most cases and looks good even on a large TV screen — 32 "and more. At the same time, achieve a high frame rate in Full HD It is relatively simple and takes up less space than higher resolution content, so Full HD shooting can be done even on aircraft that support more advanced video formats like 4K.

As for the actual frame rate, the higher it is, the smoother the video turns out, the less motion is blurred in the frame. On the other hand, the shooting speed directly affects the requirements for the power of the hardware and the volume of the finished files. 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 Full HD.

— 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 control method provided in the copter.

Modern drones are usually controlled by a remote control, a smartphone, or both. Here is a detailed description of each of these options:

— Remote control only. Management carried out exclusively from the complete remote control. The most common option, found in all varieties of drones — from the simplest entertainment models to high-end professional devices; and heavy commercial / industrial models (see "Type") are completely controlled exclusively in this way. Such popularity is explained by two points. Firstly, the functionality of the remote control can be almost anything — from a small device with a couple of levers and buttons to a multifunctional control unit with a screen for live broadcasts and displaying various specialized information. Thus, the equipment of the remote control can be optimally matched to the features of a particular copter. Secondly, you can install a powerful transmitter with a large range in the remote control (whereas the range of smartphones is very limited, and it also depends on the specific gadget model). Well, besides, the control panel is initially supplied with the drone (except that the batteries in some models need to be purchased separately).

— Smartphone only. Management carried out exclusively from a smartphone (or other similar gadget — for example, a tab...let) through a special application; communication is usually carried out via Wi-Fi. This option is good because almost any functionality can be provided in the control application; and the copter itself turns out to be convenient in transportation — in the sense that you do not need to carry a separate remote control with it. However, the range in such a control is very small — even under perfect conditions, it usually does not exceed 100 m, and in some models it does not even reach 50 m; and the actual communication range also strongly depends on the characteristics of the control gadget. In addition, the controls on the touch screen are not tactile, making blind control almost impossible. As a result, this option is very rare — in certain models of mini-drones and selfie-drones (see "In the direction"), for which the absence of a remote control and ease of carrying are important, and the described disadvantages are not critical.

— Remote control and smartphone. The ability to control the drone both from the remote control and from a smartphone. The features of both options are described in detail above; and their combination is found mainly in relatively simple devices, for which the shortcomings of control via a smartphone are not critical (although there are exceptions). At the same time, the main option for such copters is often control from an external gadget, and the remote control may not be included at all; This point does not hurt to clarify before buying. However, anyway, this control format gives the user the opportunity to choose the best option for a specific situation. For example, for recreational flights during a "sally" in nature, you can get by with a smartphone, and for aerobatic training, a remote control is better. So most modern quadcopters that can be controlled from a smartphone / tablet fall into this category.

The type of motors used in the quadcopter.

Modern copter drones are traditionally equipped with electric motors (usually one for each propeller), and by type, such motors are divided into relatively simple collector and more advanced brushless ones. Here is a detailed description of each variety:

— Collector. In motors of this type, a collector is used to switch the current between the windings — a mechanical device in the form of a ring mounted on the motor shaft and divided into separate sections. The current to this ring is supplied by a pair of fixed contacts — the so-called brushes. Such a design is very simple and inexpensive, moreover, it is repaired without much difficulty. On the other hand, collector motors have a relatively low efficiency, and brush contacts wear out and fail quite quickly due to constant friction (especially with frequent operation at high speeds). Therefore, the main scope of their application are relatively simple and inexpensive quadcopters — in more advanced technology, the brushless motors described below are often used.

— Brushless. In such motors, current switching between windings is carried out using electronic circuits, without the use of moving parts. This complicates and somewhat increases the cost of the design, but it gives a number of advantages over collector units. First of all, brushless motors are more efficient and experience less wear when running at full po...wer. In addition, it is easier to adjust the actual power in them, the range of such adjustment is wider, the accuracy is higher, and the reaction to changing the settings is almost instantaneous. With all this, modern technologies make it possible to create relatively inexpensive and affordable brushless motors, the cost of which is often only a small part of the price of the entire copter. So this option is quite popular in modern drones, it can be found even among relatively inexpensive models.