Comparison DJI Tello vs DJI Spark

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).

The speed at which the quadcopter rises up in the air or descends to the ground. Recreational, photo and video models tend to have more moderate climb/descent speeds, while professional or racing drones can rise and fall much faster. This indicator can be used to evaluate how quickly the copter can rise to a height for filming or, if necessary, avoid obstacles, and a high descent rate will be useful if the drone needs to be returned to the ground quickly and safely.

The type of camera installation that the quadcopter is equipped with.

- Built-in. A camera that is permanently installed on the vehicle and cannot be removed without disassembling the fuselage. This is the simplest option for tech who want to use a quadcopter for photo and video shooting or for flying with a first-person view (see “Real-time broadcast”); In addition, this camera design is considered more durable and reliable than a removable one. On the other hand, it does not make it possible to remove the camera to make the car lighter or replace it with another one that is more suitable in terms of characteristics.

- Removable. As the name suggests, such cameras are installed on detachable mounts. Thanks to this, the customer can remove or install the camera, depending on what is more important to him at the moment - the light weight of the car or the presence of an electronic “eye” on board. Note that in some models you can install not only a standard device, but also a third-party device.

- Absent. Drones that are not equipped with cameras at all fall into two main categories. The first does not involve the use of any cameras at all; As a rule, it includes inexpensive devices primarily for entertainment purposes, for which the “peephole” is just an expensive and unnecessary excess, which also increases the weight of the entire structure. The second type is models with...the ability to install a camera. It includes quite advanced copters - up to powerful professional machines capable of carrying a digital SLR. This option will be useful for tech who would like to independently select a camera to suit their needs. However, we note that the second type may have an auxiliary “eye” for live FPV broadcasts (see below); however, if such a “peephole” does not allow for taking photos/videos, it is not considered a full-fledged camera, and its presence is indicated only in additional notes. — Thermal imaging. A camera operating on the principle of a thermal imager - it detects infrared radiation from heated objects and forms a characteristic thermal image visible to the drone operator. Each color in this image corresponds to a specific temperature. A thermal imager equipped in a drone opens up possibilities not available to traditional optical cameras. Thus, it can be used to distinguish a person or animal against a camouflage background or in dense vegetation in an area. Thermal imaging cameras also “see” perfectly in complete darkness.

Quadcopters with a thermal imaging camera are by no means a cheap pleasure. They are used by rescuers, military, law enforcement, repairmen, hunters and fishermen. In particular, drones with a thermal imaging camera help find living people when clearing rubble, and are widely used to search for possible fires, gas leaks from pipelines, etc. In some situations, the performance of a thermal imager may be low - for example, it is not able to clearly identify an object if its temperature coincides with the background temperature (which makes it difficult to use in hot weather). In addition, the resolution and detail of the picture, even in advanced models, is quite modest. Thermal cameras in drones can be built-in or detachable.

The physical size of the photosensitive element of a camera. Measured diagonally, often indicated in fractions of an inch — for example, 1/3.2" or 1/2.3" (respectively, the second matrix will be larger than the first). Note that in such designations it is not the “ordinary” inch (2.54 cm) that is used, but the so-called "Vidiconovsky", which is less than a third and is about 17 mm. This is partly a tribute to the tradition that comes from television tubes — "vidicons" (the forerunners of modern matrices), partly — a marketing ploy that gives buyers the impression that the matrices are larger than they really are.

Anyway, for the same resolution (number of megapixels), a larger matrix means a larger size for each individual pixel; accordingly, on large matrices, more light enters each pixel, which means that such matrices have higher photosensitivity and lower noise levels, especially when shooting in low light conditions. On the other hand, increasing the diagonal of the sensor inevitably leads to an increase in its cost.

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.