Panoramic cameras for surveillance
Modern panoramic cameras provide a full 360 degree view. They help to see the whole picture on the protected site as a whole with a minimum blind spots. When deciding which surveillance cameras are better, it is worth considering that panoramic models can replace several fixed ones and are more efficient than rotary ones. EquIPped with a motorized mechanism, devices monitor objects in a circular view. Popular option. Dome model with lens fish eye, fixed to the ceiling or wall. It is advisable to use it in areas, and not replete with partitions.
Covert surveillance cameras
Surveillance can be organized with a hidden camera. They are released so that the object does not see that it is being filmed. A hidden surveillance camera can be disguised as an object, for example, a briefcase or a book. There are miniature models that do NOT exceed the size of a match head. This lens is installed in the wall, only the lens remains on the surface. Before choosing a hidden surveillance camera, it is important to know that secret surveillance of an object is illegal.
Surveillance camera. Which surveillance system is better to choose?
A well-chosen surveillance camera will provide the necessary overview of the perimeter in the room or on the site with low purchase costs. Now many of their varieties are offered, so as not to get confused in such a variety, it is important to study the technical characteristics of the devices.
Types of cameras for surveillance
First, what needs the device will be used, its technical characteristics. For example, before choosing an outdoor surveillance camera, it is important to know that the body of such a device must be sealed, preferably equIPped with a heating function. To organize monitoring indoors, dome cameras are often installed without protective covers. In addition, all latches are divided into analog, digital. The main difference between them is in the way of signal processing and transmission.
Camera with microphone for surveillance
With the development of security surveillance, the system has been improved by the presence of audio. There are many cameras on the market with a built-in microphone with great clarity and sensitivity, which can clearly record the speech of the object. A surveillance camera with sound helps to get accurate information about the situation at a guarded object, to detect a threat in time. Some models are equIPped with speakers that transmit the dispatcher’s speech to the object.
What are surveillance cameras?
A modern surveillance camera is an integral part of the security system. Such equIPment performs different types of tasks, depending on the performance characteristics, the price for it can vary significantly. Classification of cameras for surveillance at the installation site:
- Street. fixed outside the building.
- Internal. not intended for outdoor use.
By data transfer method:
- Wired. the signal is sent via fiber optic, twisted pair, coaxial cable.
- Wireless. no installation is required, power supply is required.
- Colored. shooting is exclusively in Color mode.
- Black and white. they can be used when there is a lack of lighting or in complete darkness with infrared illumination.
- Day Night. in the dark, the retainer switches from color mode to black and white.
- Cylindrical. made in the form of a cylinder.
- Modular. bare board without case.
- Dome. the shell looks like a hemisphere.
- Fish eye. panoramic devices with ultra-wide view.
Motion Sensor Cameras for Surveillance
The princIPle of operation of a camera with a motion sensor is a reaction (pre-programmed) to the movement of an object in the field of view. She can:
- Start recording information;
- Turn on the siren;
- Send a signal to the monitor by selecting a moving object in a frame.
Motion sensors are activated automatically or manually. Mostly they are infrared, differ in the range of operation (no more than 6 m), in the viewing angle (often 70 ). Before choosing an outdoor surveillance camera for a home with a motion sensor, it is important to know that it is logical to install it where the traffic is not very intense, so that the recording starts when there is a need for it.
Rotary surveillance cameras
For shooting in a spacious area, it is better to choose a PTZ camera for observation. It is equIPped with mechanics that change the viewing angle of the device. A PTZ camera automatically or with a control panel rotates the lens and captures what is happening around. The function helps to reduce the number of devices on the object, rather than limit the field of view. Most PTZ cameras are capable of zooming in on the subject. Devices can be programmed for lens rotation sequence, specified rotation angle and frequency.
Wireless surveillance camera
Compared to wired devices, wireless counterparts do not have the cost of laying cables. They send a signal using 3G, 4G, Wi Fi technology, while electricity is supplied to the device itself via a wire. But the range of their action is limited and the cost is higher than wired counterparts. Wireless models are divided into several groups:
- Wi-Fi surveillance cameras, these are IP models that work through an access point.
- VEB. model, this is a set: camera. transmitter. receiver. USB interface converter (plus special software).
- GSM. sends data via cellular communication channels (range is limited by the operator’s coverage area).
PrincIPle of operation
The surveillance system registers, prepares for archiving and recreates on the monitor data on all movements in the area, included in the view of the camera lens. It can be equIPped with auxiliary mechanisms that allow reading information about wireless communication information. There are cameras equIPped with motion sensors and timers, which makes its functionality and quality of control wider.
The basis of the operation of a surveillance camera is its ability to transmit the resulting image to a matrix that is sensitive to light with the help of a lens and special devices. The processed image from the matrix through the recorder and the server goes to the monitor or other programmed device.
Varieties of surveillance cameras
All existing cameras can be divided into the following categories:
1. At the place of application. outdoor and indoor.
To protect against moisture ingress, outdoor cameras are placed in a special case, inside which a constant temperature and humidity is maintained. Usually these cameras are equIPped with anti-vandal protection and special lighting. Distinguishes between their shape of a dome or a cylinder. PTZ cameras are common.
Indoor cameras are designed for indoor use. They are inserted into a plastic housing, not equIPped with special protection and are designed for a lower load.
2. By the method of signal transmission. wired or wireless.
In wired cameras, the signal is received using optical fiber or special cable. Wireless cameras use power supply and router.
3. By data transmission format. digital and analog.
In digital cameras, the mandatory use of an encoder is provided, which is responsible for changing the matrix signal into a digital stream. Such cameras are widely used, they can be both wired and wireless. Their advantage is ease of connection, high image quality and the likelihood of viewing the signal in real time.
Analog cameras transmit an electrical signal to the recorder. This method is already considered obsolete, although the viewing quality depends on the characteristics of the cable used. There is a device for analog transmission of images in digital quality. AHD format. With this broadcast, comments are delayed or image decomposition. Such a transmission can occur at a distance of up to half a kilometer if a coaxial cable is used and at 100 meters using a twisted pair. Its main disadvantage is that with increasing distance, color loss is possible.
4. According to the color rendering method. black and white, color and day. night:
- Black and white transmit the image in the color corresponding to the name, are undemanding to lighting, they can store more information than color ones. Their use is cheaper for organizing security;
- Color cameras provide images in color. They are more often used as internal office cameras.
5. By their appearance, cameras can be divided into the following types:
- Cylindrical. Very compact cameras, usually in a metal housing that resembles a bullet. Fastened with a bracket, used more often where covert surveillance is conducted;
- Cabinet. the most common, equIPped with a variety of control systems and external connectors, which makes its installation and configuration more convenient. They can be both with built-in and interchangeable lenses;
- Dome. the camera is housed in a dome-shaped body. They can be used both outdoors and indoors. They are distinguished by secrecy of work, excellent design, high image quality. They use effective zoom lenses, which have a variable focal length that allows you to increase the details of the image. Can be mounted both on the wall and on the ceiling;
- Cubic. a similar type of wireless cameras designed for indoor use. A small area falls into their view;
- Rotary. their use is a priority in that it allows you to remotely control the camera. You can change the viewing angle, rotate the camera and zoom in on the image. Such a camera is capable of tracking a large area;
- Fisheye. covers a large area, but produces a distorted image due to a 360-degree viewing angle;
- Modular. is a board with microcircuits and built-in lens. It can be built into any enclosure. Used for hidden shooting.
6. According to the degree of security, cameras are divided into:
- Dust and moisture resistant;
The degree of dust and moisture resistance is indicated by the IP indicator and a two-digit number, where the first number indicates protection against dust, the second. against moisture.
The vandal-proof camera is indicated by the IK index and a number from 00 to 10. The higher the number, the higher the degree of camera protection.
Explosion-proof chambers are designated with the Ex code. They are used to monitor explosive works and gas-polluted zones. For external protection, these cameras are equIPped with a special housing with a cover. Can be used both indoors and outdoors.
What are surveillance cameras
The use of cameras is becoming more and more popular every year. If until recently they could only be found at high security facilities, large enterprises, now everyone can install them, even in their own house or apartment. There are a great many of them on the modern market of products. Cameras are different Not only in appearance, but also in functional properties, and in order to make the right choice when buying, you need to have information about their distinctive features.
To make the right choice, you need to determine where the camera will be located and what tasks it will perform. It is important to consider every detail. It is advisable to remember that black and white cameras produce sharper images. When planning to install a camera indoors, you should choose a lighter one in a plastic case. When installing in places where people are staying, it is better to install an anti-vandal camera in a metal case. For outdoor use, choose a camera with a sealed housing. It is important to remember that a wide angle of view produces a blurry image.
The modern market offers a huge variety of cameras. But for the right choice it is worth careful.
What are surveillance cameras
To choose the right surveillance camera, you need to understand what criteria to evaluate the device.
The main princIPle is that there is nothing complicated here. There are many manufacturers of surveillance cameras, they all compete fiercely with each other, but there are big fundamental differences in the characteristics of comments.
With the development of technology, historically, all cameras can be divided into two groups in terms of price / quality ratio:
1. Traditional cameras. This includes classic analogue format, AHD and
2. IP cameras. Digital cameras.
Surveillance cameras: types and characteristics
The most familiar cameras. They are still chosen because of their lower price, however, the demand for such formats is falling rapidly.
Within this group, there is also a division into new and old categories.
Classic analog cameras with D1 (704×576) or 960H (960×576) resolution, users are no longer interested, even at a low price. Technologies are developing very quickly, and now, for a small surcharge, you can Get many times better image quality.
The standard analog format cameras have been replaced by AHD and HD-CVI. They can be called a new generation of analog surveillance, with an aspect ratio of 16: 9 and a resolution of HD 720p (1280×720) and Full HD 1080h (1920×1080).
The advantages of the new format are improved clarity: small details, faces, car numbers or banknotes are now visible on the recording. In addition, such analog cameras are still inexpensive.
The princIPle of operation of a traditional camera is to save the recording data to the recorder. It uses wires. you need to organize your own cable network. The picture can be displayed on a computer or TV in real time or stored in the archive. A copy of the archived recording can be transferred via a USB drive. They can also be viewed remotely from a phone, tablet or computer, via the Internet. But only if the surveillance system is connected to the world wide web, of course.
The future of surveillance. Digital: The most modern and advanced recording system. IP cameras in comparison with others have the best picture and clear detail, because the image matrix of such cameras starts from 1 megapixel and more.
An IP camera is a small computer with its own operating system and information processing system.
The footage will be stored in the camera itself on a flash drive or in the virtual cloud. In large surveillance systems, IP cameras can be connected to a DVR to store massive amounts of information. In any case, storing information on a USB flash drive directly in the camera itself is less reliable.
These cameras often do not need wires. they can record information over Wi-Fi. The function of remote access to recording or in real time is always available from any medium. From your phone, tablet or computer, you can see what is happening now in a particular room. Or raise the archive for a certain time.
For surveillance systems with a large number of IP cameras, it is better to create a separate LAN with high bandwidth. This is necessary in order not to create a load in the process of recording information and does NOT slow down the operation of other devices connected to the Internet.
IP cameras can be programmed to analyze the footage according to a variety of parameters: identification of numbers of cars, faces, Counting of people passing by. You can even filter out shots of faces in a particular color of clothing. Or search for the exact moment where the car parked near the porch drove off. Or someone opened it.
Which surveillance system is better?
A surveillance camera is not just an interesting toy that is chosen for financial capabilities. In order not to be mistaken in the choice, you should contact a specialist. Different types of surveillance installations are suitable for different tasks, and in this case the most expensive does not mean the best.
A good experienced specialist will carefully study your project and task and recommend the product that suits you.
Don’t be intimidated by a large indoor area or open area: with modern technology this is not a problem. A parking lot, a shared office or a courtyard, which a couple of years ago was work for a whole network of cameras, today will be within the power of a single observation point. And the cost of observation in this case can be surprisingly low.
Every day in the world they invent new interesting gadgets and technologies. In the next article, we will talk about observation options that you do not know exactly.
Indoor cameras are designed for indoor use. They are smaller in size and have a plastic body. The fastening of such devices is not as reliable as in outdoor ones, since it is designed for lower loads. Additional protection is also missing.
These are devices that can be controlled remotely. The camera can be rotated for panoramic shooting, change the angle of view, Zoom, etc. It is an expensive domed equIPment capable of covering a huge observation area.
This is an inexpensive option for outdoor and indoor use. The signal can be transmitted using:
- Fiber optic (for territorial distribution systems). Transmission can be carried out at a distance of up to 10 km without any additional amplification at a frequency exceeding 10 billion bits / s. With its help, you can transfer a large amount of information data.
- Coaxial cable. This is a more expensive option. It is definitely simple and reliable. The coaxial cable can be used without an additional amplifier. It is capable of transmitting data over a maximum distance of 400 m.
- Twisted pair. Signal transmission is carried out at a distance of up to 200 m. The data are transmitted through special transmitters and receivers, which are responsible for converting information. The main advantage is a high degree of protection.
- Letter part. IK;
- Two-digit code (00 to 10).
The higher the number, the better the device is protected from mechanical damage.
By signal transmission method
For this parameter, cameras can be:
A built-in encoder is required, which is responsible for converting the matrix signal into a digital stream. These cameras can be wired or wireless and have a wide range of applications.
The main advantages of digital devices are:
- Clear high-quality image;
- Real-time signal playback capability;
- Easy to connect.
But keep in mind that such systems are NOT compatible with analog cameras. The duration of the likely image delay is less than 300 ms.
At the place of operation
According to this indicator, the cameras are divided into:
The most common type. These cameras are stationary, they shoot a fixed location. For outdoor installation, the device is placed in a special thermal casing. Lens (2.8-100 mm). wide focus (to increase the observation area). The ability to change focus and viewing angle is provided by a zoom lens. The device is equIPped with a special mounting bracket.
By external execution
The design solution for all models is also different. Manufacturers distinguish the following types:
- Fish eye;
SURVEILLANCE CAMERAS. DEVICE
Obviously, the design of a surveillance camera is determined by its purpose. Since the camera converts an optical image into an electrical signal, it must include elements that carry out this conversion.
Three components without which the surveillance camera will not work:
- Signal processing unit.
We omit the Obvious moment that the lens projects the observation scene onto the matrix and see what happens next. The matrix is a semiconductor wafer (crystal) with many elementary elements (pixels), each of which, under the influence of light, generates an electric charge.
Up to this point, all types of surveillance cameras work the same way. Next, the resulting charge must be processed. This is where the differences for analog and IP cameras begin, which we’ll look at.
The device of an analog surveillance camera provides for sequential reading of information from the matrix. I will not go into technical details, but the essence of the process is that the electric charge moves sequentially through all the cells and is converted into electric current outside the crystal.
This is how CCD (CCD) matrices work. Their entire surface is used to convert light energy into electrical energy, as a result, such devices are characterized by:
- Low level of intrinsic noise;
- High level of light sensitivity.
The device of the IP surveillance camera is such that the transformation of the charge into an electrical signal is carried out directly on the matrix. For this, each elementary site (pixel) contains electronic components (transistors). Thus, the usable area for light conversion is reduced. This is a CMOS (CMOS) matrix.
As a consequence, all other things being equal, the light sensitivity is lower and the noise level is higher. A positive result of such a camera device is the formation of a digital signal directly on the matrix.
The technical characteristics of the surveillance camera always indicate the size (format) of the matrix in inches. The most common cameras are 1/4 format” and 1/3″. The larger the matrix area (1/3″ 1/4″) All the better. This applies to all parameters, but first of all:
- And permissions.
In conclusion, the signal processing unit is an electronic circuit that performs many functions: from generating an output signal to implementing various automatic camera adjustments. By and large, for an ordinary user this information in the internal device of the camera should be enough.
WHAT ARE SURVEILLANCE CAMERAS
Cameras are classified according to a number of parameters:
- Operating princIPle (analog and IP)
- Form Factor (Boxed and Unboxed)
- Climatic performance (outdoor and indoor installation), etc.
Most of the types listed on this site are considered in SEPARATE articles, so here I will briefly describe what features this or that device has and I will indicate several links to the most relevant materials.
Analog cameras have recently entered a new round of popularity due to the emergence of new technologies. Providing HD and FullHD quality at a low cost and ease of installation, configuration and operation make them very attractive for installation in private houses, apartments and summer cottages.
Analog cameras are characterized by a constant image transmission rate (25 frames per second), lack of “freezes”, full compatibility with other equIPment within the same technology.
IP surveillance cameras are convenient for use in analytics systems, as well as when organizing wireless surveillance systems and remote access for viewing via the Internet. By the way, mobile surveillance by phone or tablet has become quite popular, and so. IP technologies make it quite easy and simple to implement.
Now let’s see what kind of outdoor surveillance cameras are. There are two options here:
- The camera is fully assembled at the factory and ready to install;
- A set of a modular chamber and a hermetically (thermo-) casing.
It is worth noting that for most “household” tasks the first option is preferable. In the second case, it will be necessary to ensure the sealing of the case, often this happens outdoors in conditions of high humidity, low temperatures, so a professional approach is required here.
WHAT CAMERAS IS BETTER
This question is encountered quite often, although, in my opinion, it is rhetorical. Indeed, the best surveillance camera is the one that solves the tasks assigned to it with minimal cost.
For example, if you need to organize a general overview of the area, then the cheapest option may be a good option. However, you can consider situations in which cameras with a set of well-defined capabilities are required and it is better NOT to neglect this.
For example, for indoor surveillance under constant lighting conditions, it is sufficient to select the appropriate resolution and angle of view. Most of the second options can be relinquished rather painlessly. However, if the camera is installed opposite the entrance, this should not be neglected by the backlight compensation function.
It’s another matter if street surveillance is organized. Here it is necessary to compensate for changes in illumination and this can be done:
- Due to the electronic shutter;
- Or automatic iris control (ARD).
The second method is more expensive, but definitely better.
It should be noted that compensation for certain adverse effects on the surveillance camera can be achieved through various technical solutions. It is quite natural that some of them will be preferable in terms of cost, others due to a better solution to the problem.
For example, to monitor at night, the color camera must switch to black and white mode (this is called day-night). This is done either electronically or through the use of a mechanical IR filter. From a qualitative point of view, a mechanic is the best option.
2010-2020 G. All rights reserved.
The materials presented on the site are for informational and informational purposes and cannot be used as guiding documents