The impact of video surveillance on the human psyche

How people change under video surveillance

Technologies of the 21st century have turned video surveillance into a keen eye that monitors the actions of people around the clock. If a person sees a camera or a sign warning about its presence, he automatically begins to control his behavior. You can see more details here.

According to empirical studies of the issue of the impact of video surveillance on the human psyche, very interesting results were visible. People became more noble and acted on the basis of universal moral standards. Moreover, according to sociologists, such behavior appeared, without thinking, automatically when the presence of surveillance cameras was recorded.

With the development of society and rising economic levels, security issues are receiving more and more attention. The following is generalized and considered mainly from the point of view of individual users, such as houses, entrances, a small yard, a small store, the need to install video surveillance, how to choose the appropriate camera.

Watch the video after the event, find the cause of the accident and review it so we can understand the evidence and better understand the accident.

1. Lens focal length

Camera lenses are generally divided into two types: fixed focus and zoom. We must select a lens with a suitable focal length according to the scale and size of the scene to be observed.

Common fixed focus lenses mainly have focal lengths such as 2.8mm, 3.6mm, 4mm, 6mm, 8mm, 12mm, 16mm, 25mm, etc.

The zoom lens is divided into manual zoom and electric zoom. Manual zoom, when we need to set, according to the monitoring range, manually adjust the corresponding focus. The electric zoom can be remotely controlled to adjust the focal length of the lens by operating the keyboard, DVR/NVR, client software, etc. at the end. The focal lengths of ordinary zoom lenses mainly include 2.8-12mm, 2.7-13.5mm, 3.5-11mm, 5-50mm, etc. For lenses with larger zoom capabilities, we can choose cloudy billiard ball. Built-in lenses have 10x, 12x, 18x, 20x, 22x, 30x, 60x and other zoom capabilities. At the same time, these panoramic cameras usually support 90-degree up and down, 360-degree left and right panning to select, which can ensure comprehensive monitoring without dead ends.

The focal length of the lens is different, the viewing angle and the range that can be controlled will also be different. Below are the apparent distances and ranges of some common focal lengths. You can refer to them when choosing a camera.

1. 2.8 mm, viewing angle 90 degrees, viewing distance 5-6 meters
2. 3.6 mm, viewing angle 82 degrees, viewing distance 6-8 meters
3. 6 mm, viewing angle 60 degrees, viewing distance 10-15 meters
4. 8 mm, viewing angle 45 degrees, viewing distance 15-20 meters
5. 12mm, viewing angle 30 degrees, viewing distance 25-30 meters
6. 16 mm, viewing angle 22 degrees, viewing distance 30-35 meters

The shorter the focal length of the lens, the larger the viewing angle of the observation screen and the closer the visual distance. The viewing distance is usually determined by multiplying the focal length of the lens by 2 and then floating it up a little, for example 2.8*2=5.6, so the appropriate viewing distance for a 2.8mm lens is about 5-6 meters.

Of course, the above are only approximate reference values, which are very useful for choosing the focal length of a surveillance camera lens in general household or small surveillance projects. The more accurate lens focal length, viewing angle and viewing distance also depend on many factors, such as the target surface of the lens, viewing distance measurement standard and so on.

Now we have more options in consumer smart home cameras - panoramic cameras. The panoramic camera uses 180-degree, 360-degree panoramic lens, and the camera's viewing angle can reach 180 degrees, 360 degrees. Thus, in a small office, living room and other spaces, the panoramic camera can be completely covered to ensure that there are no monitoring dead ends.

The focal length of the panoramic lens is relatively short, such as 1.44mm, 1.1mm, and the viewing distance is very short, so the best application scenario for the panoramic camera is indoors, such as the living room at home, meeting room, etc.

2. Selecting the appearance of the camera

How to choose the right camera appearance? It mainly depends on our installation location. This is very clear and very precise.

If we want to mount the camera on the wall, we usually choose a gun camera. If it is installed on the ceiling, then a dome camera is usually chosen. If it is an outdoor environment, we should pay attention to the camera should be waterproof and dustproof, and pay attention to the IP protection level of the camera. Generally, the IP65 camera can meet the outdoor requirements of waterproof and dustproof.

In addition, equipped with a suitable mounting bracket, the bolt camera can also be installed on the ceiling, and the dome camera can also be mounted on the wall. I won't expand on this here.

In some large outdoor surveillance scenes, we can choose a PTZ camera that can rotate 360 ​​degrees. The same thing happens indoors. For example, we can place a small panoramic camera on a corner table and rotate it to clearly see the entire room when accessed remotely via a mobile phone.

3. Camera function selection

According to our surveillance needs, choose cameras with different functions.

Transmission mode, we can choose, video cable transmission, network cable transmission, WiFi transmission, wireless AP transmission, 4G mobile network transmission and other various camera function transmission methods.

Audio, if we need to control the sound while monitoring the image. Then we have to select a camera with audio function.

Under different lighting conditions, if the camera is installed indoors, it should be illuminated from outside the door or window. Since the light is different inside and outside, you need to choose a camera that supports advanced dynamic features. If you need to illuminate and see the car license plate clearly at night because the car's headlights are very bright, you need to use a camera that supports strong light suppression.

POE power supply. Sometimes, if it is not convenient to power the camera with a power cord, you can choose a network camera that supports POE power. Just set up a POE switch on the back panel.

Starlight level, if you monitor the environment, there is little light at night, and you hope the monitoring picture at night will be colorful, you can choose the starlight level camera. It can support color monitor screen in low light. If there is no light at all at night, you can use white light to fill the camera with light, and you can maintain a colorful surveillance picture at night.