Comparison A4Tech PK-930HA vs A4Tech PK-920H

The maximum video resolution supported by the camera. WVGA is the most modest of the widely used formats — it does not belong to high-definition (HD) standards. Webcams of this format usually have a resolution of 640x480 to 1024x768; you should pay attention to them if you need the simplest and most inexpensive solution.

Historically the first of the high definition HD (720p) standards. Initially, it assumed a resolution of 1280x720, however, in webcams, models with a different frame size are also included in this format — in particular, 960x720 and 1280x960, which have a 4:3 aspect ratio of the frame (unlike the original 1280x720, for which it is 16:9 ). Anyway, HD-models are relatively inexpensive and not particularly demanding on the quality of communication, however, they allow you to get a fairly detailed “picture”.

Focus method — focus — provided in the design of the camera.

The simplest and most common option is manual focus; it requires some setup steps, but does not cause any particular difficulties, besides, it allows you to set the sharpness as you wish, without relying on automation. Autofocus, in turn, saves the user from having to fiddle with the settings, however, it is also more expensive. In addition, autofocus systems may not work as you would like, and they still sometimes have to be adjusted manually (however, such a need is extremely rare).

The viewing angle determines, first of all, how wide the field of view of the camera is, what area of the scene being shot falls into the frame. Accordingly, a wide viewing angle allows you to capture more space and the lower the likelihood that something of what is happening will be behind the scenes. On the other hand, it should be taken into account that a strong increase in viewing angles 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.

— Face scanner (FaceID / Windows Hello). A specialized scanner for facial recognition. Note that this is not just about “recognition from a photograph”, but about a full-fledged three-dimensional scanning using a special IR sensor. This allows very accurate and reliable recognition to be achieved. And thanks to advanced algorithms, accuracy is maintained even when facial hair changes, putting on and taking off glasses, and other similar changes. As for the purpose, the face scanner is mainly used for user authentication — in the case of Windows it is Windows Hello, and for iOS devices it is FaceID.

— Quick capture button. A button similar to the capture button on cameras: when you press it, the webcam takes a picture and saves it to a dedicated folder. Thus, a minimum of effort is required from the user — literally one click on the button is enough to get a digital photo immediately stored on the computer. The quality of such shots is not high and this option is not able to replace a full-fledged digital camera, but it may well come in handy when speed or ease of taking a picture is important.

— Microphone. The presence of a built-in microphone allows you to use the camera not only to work with video, but also to transmit or record voice and other sounds. This is often more convenient and cheaper than buying and using a separate microphone. And the presen...ce of noise reduction allows you to make speech more clear by removing extraneous sounds from the air. Webcams with a noise-canceling microphone are primarily needed for professional use when you need a clear transmission of words — for online lessons, video conferences, etc.

— Speaker. The presence of a speakerphone will allow you to communicate with the interlocutor without the use of additional accessories (headphones, speakers). Actual is in models for conferences. However, the sound quality and volume can be mediocre.

— Motion detector. A feature that allows the camera to respond to movement in the frame. Most often used to automatically start recording or broadcasting if a moving object appears in the field of view. However, this function is not very common — it is convenient mainly for surveillance systems, and webcams are rarely used in such systems (it is more convenient to use specialized cameras in them).

— Night shot. The ability to use the camera at night, in low light. The specific implementation and capabilities of this feature may vary. So, some models use a highly sensitive sensor that can work effectively in low light; in other models, IR illumination is installed, invisible to the human eye, but perfectly perceived by the sensor. These nuances should be clarified in each case separately. However, it is also worth noting that webcams are rarely used in twilight or darkness, and even in such situations it is more reasonable to use regular backlighting (see below): it preserves the colours in the image, while shooting at night usually gives a black and white picture. .

— Backlight. Own lighting system built right into the camera — usually in the form of several LEDs. Designed for shooting in low light conditions; at the same time, in contrast to night shooting (see above), in this case, the illumination is carried out in the visible range. This allows you to keep the image in colour.

— Monitor mount. Mount for fixing a webcam on a computer monitor or laptop display. It is this arrangement that is most often optimal: for example, during a video call, it will give the impression that the user is looking at the interlocutor, although in fact his gaze may be directed not at the camera, but at the screen. In addition, the camera installed on the monitor does not take up space on the table, and the risk of accidentally touching it is minimal.

— Tripod mount(1/4" thread). The presence of a 1/4" threaded socket on the camera body. It is this size that is standard for modern tripods and is used in most of these devices. So this feature allows you to mount the camera on a tripod without using adapters and other additional equipment.

— Protective curtain. A movable shutter with which you can cover the webcam lens. Such a device provides additional security, because your PC or laptop can be hacked and watched through the camera. In addition, the shutter protects the optics from various contaminants.

The range of rotation angles in degrees supported by the webcam. In this case, it means turning the camera to the right or left, without tilting back and forth.

Tilt angle interval forward-backward relative to the vertical position of the camera. Tilt angle adjustment allows you to quickly redirect the lens to the desired plane for the best view. The parameter is measured in degrees.

Types of indicators (usually light) provided in the design of the camera. In modern models, there are (separately or together) two types of indicators:

— Nutrition. An indicator that indicates that everything is in order with the power supply. On some models, this indicator only works when the camera is turned on and ready to use, on others it can also work in standby mode — for example, it will glow in a different light than when the camera is on.

— Activities. An indicator that indicates that the camera is shooting video — and, accordingly, it is being recorded or broadcast on the Internet. Such an indicator makes it easier to keep track of the shooting mode and avoids unpleasant situations, such as accidentally broadcasting to the Internet from a camera that you forgot to turn off.