Comparison SJCAM SJ8 Pro vs Xiaomi Yi 4K Action Camera 2 Basic Edition

The degree of dust and water protection of the protective case supplied with the camera.

Protected case will save your camera from dust, water, temperature changes, shocks, etc. The specific degree of protection is indicated according to the international IP (Ingress Protection Rating) system, according to which each device is assigned a code of the form IPXX, where X is replaced by specific numbers. The first of them characterizes the protection against the penetration of foreign objects (from 0 to 6, where 0 is no protection). Usually, in boxes for action cameras, this indicator does not go below 5, because otherwise the container would have too large gaps, and its use simply would not make sense. Level 5 provides dust resistance — dust can get inside the case, but in small quantities that do not affect the device inside. Level 6 corresponds to complete imperviousness to dust.

The second digit is protection against liquid ingress (from 0 to 8, where 0 is no protection). Usually, the minimum level of protection against water is 6.

6 — protection against short-term immersion (for example, falling into a sea wave);
7 — protection against temporary immersion under water (up to 30 minutes) to a shallow depth (up to 1 metre), without continuous operation in immersed mode;
8 — protection against immersion to a depth of more than 1 metre for a time of more than 30 m, with the possibility of continuous...operation underwater. The specific level of protection of level 8 can be quite impressive — up to the possibility of diving to several tens of metres.

Note that protective cases for action cameras can be sold separately. Therefore, if the capabilities of the complete container do not suit you, there may be a more secure case on the market. On the other hand, in general, it is still more convenient to buy such an accessory immediately with a camera — so as not to waste time and effort on choosing the right protective case.

Camera ability for recording WVGA (480p) video.

The most popular resolution options provided by this standard are 640x480 and 848x480; there may be other options, for example, 736x480 or 720x576, but the resolution of such a video is very low by modern standards.

Another important parameter indicated in the specs of the video is the frame rate. The higher it is, the smoother the picture looks, and the less moving objects are blurred in the frame. Accordingly, the higher the frame rate, the better the dynamic scenes will look on the video. A value of 120 fps or more usually indicates that the camera can shoot video in slow-motion format (although it should be specified separately). At the same time, many models with high fps allow you to set a lower frame rate than stated in the specifications — for example, a camera for 120 fps can also support 30 and 60 fps. This feature is useful in cases where you need to save memory — the higher the frame rate, the more space the video takes (at the same resolution), and by reducing the number of frames per second, you can fit more material in the same amount of memory.

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.

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.

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.

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.

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.

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.

— Photo during video. The ability to take photos directly while recording a video — usually using a separate button. Thus, it is convenient to fix the most significant moments of what is happening. Such photos are much better in quality than "freeze frames" from the captured video.

— Serial photo shoot. This feature allows you to take several pictures at once in a short period (usually it is a fraction of a second). A series of shots increases the chance of capturing a good moment, which can be very important given the specifics of using action cameras.

— One click recording. The ability to quickly turn on the camera for recording — literally at the touch of a button, by the name. Moreover, such a button works even if the device is turned off. However, the recording inevitably starts with some delay; but often this delay is a fraction of a second.

— Online streaming. Ability to stream video to popular services like YouTube and social networks (Facebook, Instagram, TikTok, etc.). Usually, the online streaming function is implemented when the action camera is connected to the Internet via a Wi-Fi network, less often via a wired connection. Communication with the World Wide Web can be held directly or through a smartphone or computer. It will require the use of appropriate software.

— Time lapse. A special mode of operation of the action camera, in which video recording is carried out at a slower frequency is mainly used for filming slow processes. Thus, for example, a long journey or a long sunset can fit into a 3-minute video.

— Auto-rotate. The function of automatic rotation of the captured photos and videos to the position corresponding to the position of the camera. Without this feature, all footage during playback would be displayed strictly in landscape orientation, and footage shot with the camera upside down or upside down would have to be rotated in a photo or video editor. Usually, at the beginning of video recording, auto-rotation is blocked — so that the position of the frame at any time corresponds to the rotation of the camera itself relative to its original position.

— Photo panoramas shooting. The ability to use the camera to take panoramic photos. In traditional action cameras (see "Product type"), such shooting is carried out as follows: the camera takes several separate photos, which are then glued into one image. Regarding panoramic and 360-degree models (see ibid.), it is worth noting that not all such models support shooting in panoramic format, so it is advisable to check the availability of this function separately.

— Key points labels. The ability to add special marks to the footage that indicate key moments. While viewing such videos, you can go directly to the labels — this is easier than manually searching for the right moment. This feature is especially useful when shooting long videos, as well as when numerous individual files. The label, usually, is placed right during the shooting by pressing a special button or by voice command.

— Night shooting. Special mode for recording in low light conditions. The specific implementation of this function may be different: in some models, the sensitivity of the sensor is increased, in others, shooting in the IR range is used. Accordingly, specific features may vary: not every camera with this function can shoot in complete darkness, and these nuances should be clarified separately.