Shooting above 4K
The maximum resolution and frame rate of video taken by the camera in a standard
higher than 4K. Since such formats have not yet become widespread, the number of devices with the corresponding resolution is not so large.
Digital stabilization
The presence of a digital (electronic) stabilization system in the camera design.
Any stabilization is intended to compensate for small juddering of the image that occurs due to the instability of the hold in the hands, vibrations from the motor or road roughness (when used in transport), etc.
Digital stabilization is carried out as follows: a reserve area is allocated along the edges of the sensor, which under normal conditions does not participate in the formation of the final image. If the device is being shaken, the camera electronics select certain parts of the image from the reserve and build the image in such a way that in the end, it remains stable.
Compared to other methods of stabilization, digital systems are extremely simple and reliable. Moreover, they are inexpensive and have almost no effect on the weight, dimensions, and price of the camera. At the same time, with this method of stabilization, the effective area of the image sensor is reduced, which can adversely affect the image quality and the amount of noise on it.
Optical stabilization
The presence of an optical stabilization system in the design of the camera.
Any stabilization is intended to compensate for small juddering of the image that occurs due to the instability of the hold in the hands, vibrations from the motor or road roughness (when used in transport), etc.
Optical stabilization is carried out by a system of movable lenses and gyroscopes in the camera lens; such a system monitors the vibrations of the device and adjusts the optics in such a way that the image falling on the sensor remains motionless.
The optical method is considered more advanced than the electronic method described above: it allows you to use the entire area of the image sensor, which contributes to good image quality. At the same time, the stabilization mechanism turns out to be quite complex and expensive, and often quite fragile. In addition, it increases the weight and dimensions of the entire device — not by much, but sometimes this may be important. And the miniaturization of such systems further affects the price. As a result, the presence of an optical stabilizer is most often a sign of a fairly advanced camera.
Noise cancelation
The presence
of a active noise reduction system in the design of the action camera.
This function is relevant only for models with the ability to record sound (see above). The noise reduction system, by the name, monitors extraneous noise in the recorded sound (for example, the rumble of the wind in the microphone array) and eliminates them — thus, the camera captures only “useful” sound with a minimum of ambient noise. Of course, even the most advanced of these systems are not perfect, and errors in operation are inevitable — the camera may miss some noise or reduce the volume of a “useful” sound. However, in most cases, noise reduction somehow positively affects the quality of the recorded audio.
Microphones
The number of built-in microphones provided in the camera.
This parameter is indicated only for models that have
more than one microphone. This design provides additional capabilities, but the range of these capabilities depends on the number of microphones and the features of a particular model. So, most often such devices have two microphones; this can be a pair for recording stereo sound, or one microphone can work to record sound, and the second one can act as a sensor for the noise reduction system (see above). A larger number - 3 or 4 microphones - is found mainly in 360-degree cameras (see “Product type”), where such equipment is used to record “surround” multi-channel sound.
Megapixels
The number of megapixels in the action camera sensor, in other words, the resolution of this sensor(1 megapixel is 1 million photosensitive points).
There is an opinion that the higher the resolution, the better the image quality. It is true from the point of view that manufacturers are trying to install high-resolution sensors in advanced cameras. At the same time, there are no strict dependencies here, and from the technical point of view, the number of megapixels determines only the maximum image resolution that can be captured using this sensor. The quality of this picture will depend both on several features of the sensor itself (size, type, special design solutions), and the specs of the camera. So when choosing, you should focus not so much on the resolution of the image sensor, but on the general class of the camera and reviews with examples of footage.
Sensor
Additional information regarding the sensor installed in the lens. This item can specify both the diagonal size (in inches) and the sensor model, and sometimes both parameters at once. Anyway, such data is provided only if the device is equipped with a high-class image sensor. With the model, everything is quite simple: knowing the name of the sensor, you can find detailed data on it.
The diagonal of the image sensor is traditionally indicated in fractions of an inch — accordingly, for example, a 1/2.3" sensor will be larger than 1/2.6". Larger sensors are considered more advanced, as they allow for better image quality at the same resolution. This is because due to the larger sensor area, each pixel is also larger and receives more light, which improves sensitivity and reduces noise. Of course, the actual image quality will also depend on several other parameters, but in general, a larger sensor size usually means a more advanced camera.
Aperture
Action camera optics aperture. This characteristic determines how much the lens weakens the light flux passing through it. This parameter is indicated by a fraction, for example, f/2.8. The smaller the number in such a designation, the higher the aperture ratio and the more light the lens can transmit. A high aperture ratio is important, first of all, when shooting in low light conditions: it allows you to capture an image without “raising” the sensitivity of the matrix and without creating additional artefacts in the form of noise, and in photo mode, it also allows you to work with shorter shutter speeds (which is useful for dynamic scenes). In addition, the higher the aperture ratio, the lower the depth of field and the easier it is to get a blurred background. Note that for simple shooting scenarios, this parameter does not play a decisive role, but for professional tasks, it can be very significant.
Photo resolution
The maximum resolution at which the action camera can take photos. Specified in pixels horizontally and vertically.
This parameter is directly related to the resolution of the image sensor(see above): the total number of pixels in the photo, usually, corresponds to the number of pixels in the sensor. For example, a photo resolution of 4608x3456 corresponds to a sensor of 15925248 pixels, or approximately 16 megapixels. If the number of pixels in the photo is greater than the claimed resolution of the sensor, then the manufacturer uses software tricks that allow you to improve the photo resolution to a higher one than originally. This reduces the cost of devices but also affects the quality of images.
Theoretically, high-resolution images can provide good detail, but in fact, much depends on the specs of the sensor (primarily physical size) and image processing features.