HD (720p)
The ability of the camera to record HD video (720p).
The official HD specification provides a resolution of 1280x720. However, in action cameras, there may be resolutions slightly different from this parameter, for example, 1080x720 or 1440x960. Anyway, HD is the most modest of today's high-definition standards, which, nevertheless, provides a fairly clear and detailed image.
Another important parameter given in this paragraph is the frame rate. The higher it is, the smoother the movement in the frame will be, and the details in dynamic scenes will be visible clearly. Technically,
30 fps or even less is enough for video, but
60 fps is considered the perfect value — at this frame rate, motion blur becomes almost imperceptible and at the same time the size of the captured files remains within reasonable limits. However, there are cameras on the market with higher frame rates at HD resolutions —
100 fps,
120 fps,
200 fps and even
240 fps. This speed is usually used for recording slow-motion video, but such a possibility needs to be specified separately.
Quad HD
The ability of the camera to shoot QuadHD video.
This standard includes an extensive set of resolutions — from 1440 to 3456 pixels horizontally and from 1440 to 2160 pixels vertically, with almost two dozen intermediate options. It is a rather specific transitional option between the relatively inexpensive FullHD 1080p and the demanding UltraHD 4K, allowing you to shoot higher resolution video than 1080p without significantly increasing the cost of equipment. Note that pure QuadHD resolutions are rare in TVs and monitors, but modern technologies make it possible to comfortably watch videos of this format on any high-resolution screen.
Another important parameter given in this paragraph is the frame rate. The higher it is, the smoother the movement in the frame will be, and the details in dynamic scenes will be visible clearly. For example, a filming speed of
25 fps or
30 fps approximates the standard frame rate in film and television; such an image is quite viewable, but fast-moving objects in the frame will look blurry. With an increase in speed to
60 fps, this effect becomes almost imperceptible. The highest QuadHD frame rate found in modern action cameras is
120 fps; this frequency is used when shooting slow-motion video (as well as models with a frequency of
100 fps) because at a n
...ormal playback speed, 60 fps is enough.Ultra HD (4K)
The ability of the camera to shoot Ultra HD 4K video.
This format covers several resolutions in which the horizontal frame size is approximately 4K pixels. The most popular in action cameras is 3840x2160 (twice the FullHD frame on each side), but there are other options — for example, 3840x1920, corresponding to an aspect ratio of 2:1. In general, 4K is a kind of successor to Full HD: among HD standards that surpass Full HD, UltraHD is the most popular, in particular, many advanced TVs are produced with 3840x2160 screens. On the other hand, this format is quite demanding in terms of processing power and memory, so it is relatively rare in action cameras, mainly among premium models.
Another important parameter given in this paragraph is the frame rate. The higher it is, the smoother the movement in the frame will be, and the details in dynamic scenes will be visible clearly. However, in UltraHD mode, most modern action cameras produce a very low frame rate — most often
30 fps, and in some models
24 fps or even
15 fps. This video is quite viewable, but fast movement in the frame may look blurry. There are cameras capable of shooting UltraHD at a solid speed of
60 fps — the blurring effect during such shooting is almost imperceptible. However, such a model cost is high.
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.
Field of view
For models with several lenses, as a rule, this parameter is indicated for each lens.
Most often (unless otherwise indicated), the specifications indicate the field of view by the diagonal of the frame; in some
ultra-wide-angle lenses it can exceed 180°. A special case is made up of lenses for which a 360° view is declared: this means that the optics cover the entire hemisphere in front of it. Such lenses are found in panoramic and 360-degree cameras (see “Product type”).
In general, the field of view primarily determines what area of the scene is being captured into the frame. Accordingly, the wider it is, the more space the camera captures, and the lower the likelihood that something that is happening will be off-screen. On the other hand, it is worth considering that a strong increase in the field of view leads to distortions of the “picture”, especially at the edges, as well as, to a decrease in the size of visible objects and a decrease in detail. Detailed recommendations regarding choosing a camera based on this parameter can be found in special sources.
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.