Comparison Syma X21W vs ZEROTECH DOBBY

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.

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 of photos that the standard quadcopter camera can take. This parameter is directly related to the resolution of the matrix (see above): usually, the maximum resolution of a photo corresponds to the full resolution of the matrix. For example, for pictures of 4000x3000 pixels, a sensor of 4000 * 3000=12 megapixels is provided.

Theoretically, a higher resolution of photography allows you to achieve highly detailed photographs, with good visibility of fine details. However, as in the case of the overall resolution of the matrix, high resolution does not guarantee the same overall quality, and you should focus not only on this parameter, but also on the price category of the quadcopter and its camera.

Also note that the high resolution of the camera affects the volume of the materials being shot, for their storage and transmission, more voluminous drives and “thick” communication channels are required.

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.

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.