Number of megapixels
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.
HD filming (720p)
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.
Live video streaming
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.
Video transmission frequency
The frequency of the radio channel used to transmit the video stream from the camera on board the drone to the receiving device: smartphone or tablet, control panel or pilot’s video glasses. The most common frequencies are 2.4 GHz and 5.8 GHz; video data transmission at a frequency of 1.2 GHz is less common. This parameter directly affects the quality and stability of the video signal, depending on environmental conditions, as well as accompanying interference from other devices. Thus, for receiving video from FPV drones, the most preferable frequency is 5.8 GHz, which is due to a wide selection of channels and high data transfer rates.