How Effective Night Video Surveillance Helps Prevent Accidents
Peter Beare, Executive Director, Extreme CCTV

Although IP cameras are now much more beneficial to security end users, almost all of them suffer from a critical problem every night - darkness.

FACT: Cameras are dark sensitive.
"No light - no image", this principle is applicable to any video surveillance systems (analogue and IP). For IP systems, though, lighting becomes more important as performance drops more. In an analog system, lighting only affects image quality. In an IP video surveillance system, low lighting not only affects video quality, but can also be a catalyst for system problems.

FACT: Video noise increases data flow from a video camera
Poor performance at night leads to increased noise in the video signal, which is the enemy of compression. Poor compression accordingly affects the increase in bitrate. For example, with good lighting, the signal transmission rate from an IP camera will be only 10 Kb / s. When dusk falls, the speed can already increase to 100 Kbps - a 10-fold increase - resulting in reduced efficiency and system potential.

Active IR is a must for mission-critical low-light IP applications
It doesn't matter what kind of system it is, analog or network, in fact, all CCTV cameras transmit high-quality images in daylight conditions. However, today's security systems require 24/7 performance, so running full-time at night impacts overall system efficiency.

As soon as the sun sets, network bandwidth requirements grow exponentially. What to do? For IP systems, 5 main cycles of operation can be deduced:

1. Video shaping
2. Video encoding and compression
3. Video transmission
4. Video storage
5. Video analysis

The video imaging step can be called the "initial edge" of the system. After all, if the video signal disappears, other stages of encoding, transmission and storage will not receive data to work with. As a result, the last stage of real-time video analysis will also not have useful data for analysis.

To understand the relationship between darkness and bandwidth, consider the camera's automatic gain control (AGC) feature, which amplifies the signal in low light conditions. With the amplification of the video signal, the noise of the video image also increases, graininess appears.

During the day, compression algorithms do a good job, and the bitrate has acceptable values. As soon as dusk falls, the AGC function starts to work, creating more noise. Eventually, the image becomes grainy at night. In this case, the bitrate acquires unacceptable values ​​and can be ten times higher than the daily rate, even for stationary video cameras.

Two photos of the same dark scene, without IR (left) and with IR (right).
The image with infrared illumination is evenly illuminated and the signal-to-noise ratio is 15 dB. In an image without IR, the signal-to-noise ratio is only 5dB and there is much less information, but the file size is larger, which leads to an exponential increase in bitrate.

To understand this rise in data rates, it is necessary to have a basic understanding of compression algorithms. The basic principle of compression is to eliminate useless information in order to reduce the file size. Compression requires a trade-off between image quality and file size. The maximum compression level creates a smaller file but lower image quality. The minimum compression level creates better pictures, but the file size will be larger.

The most popular compression algorithms now are H.264, Wavelet, JPEG, MPEG or M-JPEG, which are known for low information loss. They use one of two data transformation principles:

• Removal of redundant video signal information that is not visible to the human eye, such as close color gradations.
• Removal of redundant information that is duplicated in one frame or between frames, such as large areas painted in the same color.

The noise caused by AGC interferes with the compression algorithms of modern IP cameras. Compression algorithms misinterpret AGC-induced noise and graininess in images as useful information that cannot be compressed, as unnecessary or redundant. Thus, images are less efficiently compressed at night, resulting in larger file sizes that also contain less useful information.

The direct relationship between night work, compression and speed is clear:

It seems that the easiest way to solve this problem is to disable AGC. However, as a result of this, we would get a bad or even completely useless image at night. Obviously, at night, the effectiveness of a video surveillance system is of great importance to ensure reliable security.

The best solution for efficient operation of IP systems at night is to use infrared stage lighting equipment. Installing an IP camera with built-in infrared illumination or an IR illuminator provides high quality night footage with low noise. Under these conditions, automatic gain control (AGC) becomes unnecessary and the compression function works well. The data transfer rate fluctuates within acceptable values, ensuring stable network operation.

Bosch Extreme CCTV solves the problem of bitrate growth with Black Diamond infrared technology. The award-winning Black Diamond infrared illumination eliminates both foreground highlights and underexposed areas in the background.

Black Diamond technology is built into EX85 megapixel IP cameras and UFLED series floodlights.

All of the above leads to the basic and compelling facts: analog or IP video surveillance requires adequate lighting. Reliable video surveillance is based on clear images, 24/7. For clear video images around the clock 24/7, you need effective video surveillance at night. Effective video surveillance at night requires infrared illumination with high performance.

To date, there are a lot of functions of CCTV cameras, firstly, this is due to the fact that each manufacturer is on the path of constantly improving the characteristics of its products. Secondly, the same functions can be called differently by different manufacturers, in our case, there may also be a different translation, because. localization in Russia is usually handled by a distributor. Third, and most unfortunate, many of the new features are just marketing gimmicks, just new names for existing features.

All this makes the task of choosing the right video camera extremely difficult even for a technically savvy person.
In this article, we will consider only the most common misconceptions encountered when choosing CCTV cameras. And in no way will we consider errors in the design and installation, although there are no fewer of them.

Mistake #1.Expect the same image quality from a CCTV camera as on a "TV"
The prerequisite for this extremely widespread misconception is, in fact, the goal of both a professional television or household camera and a video surveillance camera is the same - to record a video image. However, there are far more differences than similarities.

Surveillance cameras are designed to work 24 hours a day, 365 days a year, for 10 years continuously.

• IP surveillance cameras -price from 3 840 rubles

Mistake #2. The higher the resolution, the better the camera
It is important not to substitute concepts; for the purposes of video surveillance, one of the most important tasks is detailing, i. the opportunity to consider all the details and details. Naturally, resolution greatly affects the ability to detail, but not only it. If we pay attention to the characteristics of video surveillance cameras with different resolutions, we will see that all cameras will have the same physical sensor size, usually 1/2.7 or 1/3, and megapixel values ​​​​from 1.3 MP to 3 MP. That is, an increase in the number of megapixels is achieved by reducing the size of the pixel, which means that the surface that falls on one pixel will decrease, which means that the photosensitivity as a whole will decrease.

If we compare the light sensitivity of a camera with the same sensor size and a different number of megapixels, we will definitely see that the light sensitivity of a camera with a smaller number of megapixels will be higher.

This video clearly compares the IMX 225 sensor - 1.3MP and the IMX 323 sensor - 2MP

Conclusions:
Optimal at the moment for most tasks isresolution from 1.3 to 2 MP . If you need a camera with a higher resolution, the physical size of the sensor should also be larger.

Mistake #3. The more light sensitivity, the better the camera
Probably one of the most desirable, but also the most expensive feature, the slightest increase in light sensitivity entails at least a 30% increase in the cost of the camera. Trying to understand and compare ISO values, you will encounter a number of problems.

First problem
Measurements of photosensitivity values ​​are not normalized, i.e. each manufacturer measures in their own way, someone measures on the sensor, someone on the camera as a whole, someone on the object that the camera is looking at. As you understand, these will be three different values.

Second problem
The measurement system is not standardized enough, of course there is international unit of illuminance lux (LC), and it is of course standardized, but many parameters are not taken into account when calculating it, for example, whether there is reflected light or not, in what range the light should be, in what spectrum, etc.

Third problem
For many reasons, only one series of matrices can be correctly compared. All this makes the task of correct comparison of camera photosensitivity very difficult even for a person experienced in video surveillance systems.

Conclusions:
In most cases, choosing cameras with high light sensitivity, you overpay for artificially high values. One of the most reliable metrics of the actual ISO value is the size of the sensor, the larger the sensor, the larger the ISO value.

If high ISO values ​​are necessary for you. The best solution would be to use cameras only from trusted manufacturers, or contact video surveillance specialists with extensive practical experience in designing, installing, and maintaining video surveillance systems.

Mistake #4. Using only ALL-IN-ONE cameras
One of the latest marketing tricks, which, if you do not peer closely, sounds quite attractive. The advantages of ALL-IN-ONE cameras include small dimensions, and fairly wide functionality in a small all-weather case, and ease of transportation and installation. IP cameraBewardbright representative of the ALL-IN-ONE family

But as you probably already understood, even the most attractive front-end (front-end) often hides a completely ambiguous back-end (back-end). And the first minus is the decrease in the overall functionality of the camera. In such small cameras it is simply physically impossible to place a large matrix, a large number of LEDs.

As a rule, in such cameras, an M12 format lens is used, as a result, a decrease in the range of focal lengths, and a decrease in the amount of light captured by the lens, as a result, low light sensitivity. The relative all-weather capability of such cameras is up to -20 degrees Celsius. Also in such chambers, as a rule, there are no dry contacts.

Conclusions:
If you have a difficult exposure, if you need a powerful backlight, if the camera will work in frosts far exceeding -20 degrees Celsius, if you need a safe cold start system, dry contacts. Then ALL-IN-ONE is not your choice.

Mistake #5. Anti-vandalism will protect the camera from any impact
It is important to understand that if an attacker decides to break the anti-vandal camera and he has something other than his bare hands, such as a hammer, he will disable the camera one way or another. Those. the task of anti-vandal cameras is to hold out for enough time to film the attackers, for their further identification.

Accordingly, if you assume in advance with a high degree of probability that they want to disable the camera, then perhaps you need to choose not an anti-vandal camera, but simply place the camera out of reach from intruders, for example, at a great distance, or at high altitude, naturally, the characteristics and location such a camera should allow it to identify people. One of the reliable indicators of anti-vandalism is compliance European standard EN 62262 protection of electrical equipment from external influences. According to which the larger the value IK code the more impact resistant the camera is.

View Axis CCTV Camera Shock Testing

Conclusions:
Think carefully about the tasks that the camera faces and the conditions in which the shooting will be carried out, the simplest solutions are not always the most correct ones.

Mistake #6. The longer the IR range, the better.
A subtle technical point is that the increase in the range of IR illumination occurs, as a rule, due to the use of collimator lens .


An important feature of the use of a collimator is that an increase in the illumination range is achieved by reducing the viewing angle.
The second negative moment if you pay attention to the picture, even that part of the frame that is informative (the figure of a young man) is quite strongly illuminated. All this in a compartment significantly reduces the information content of the resulting image.

Conclusions:
An increase in the IR illumination range should be achieved by increasing the power of the IR diodes, or their number. If a collimator is used, it is important to use only adaptive collimator lenses. The use of zoom illumination will allow, when changing the zoom of the camera, to adjust the illumination range evenly with the zoom. For example, there is such a backlight on the Beward B89L3270Z18 camera.

Mistake #7. Save on outdoor cameras
The well-known truth - the miser pays twice, in the case of street surveillance cameras is not entirely true, in the case of street cameras, the miser will have to pay three or even four times.
Even in Moscow, very cold days are quite Not unusual , and the temperature minimum recorded in Moscow is -42 °C.

Most Chinese and European brands, however, produce CCTV cameras in the temperature range down to -20°C. Therefore, the failure of such a camera even in Moscow is quite likely. The specificity of outdoor video surveillance cameras is that they are usually located at a considerable height. Replacing the camera in the winter is at its best, the pleasure is not cheap. And no less important is the question of what to change, to change to the same camera, which means that with a high degree of probability they will face the same problem again. If you change to a camera from another manufacturer, then there is a chance you will encounter compatibility problems.

Conclusions:
If outdoor cameras are part of your video surveillance system, pay special attention to the characteristics and choice of manufacturer.

Mistake #8. To think that ONVIF guarantees equipment compatibility
On the one hand, ONVIF is of course a universal standard used by all leading manufacturers. One of the main points to keep in mind is that there are different versions of this standard. If your DVR supports the ONVIF 2.0 format, then most likely it will not understand the IP camera that supports ONVIF 1.4.

Conclusions:
The task of integrating equipment from different manufacturers is complex and must be approached with the utmost attention, and even in this case, there is a high probability that 100% compatibility cannot be achieved.

Useful materials

We reviewed 4 outdoor surveillance cameras from different price segments at once. They ruthlessly put the models outside and connected them to one antenna that amplifies the signal of the mobile Internet.

We often encounter the fact that employees of many Russian enterprises initially perceive video surveillance as an alien evil. At best, they want to leave everything as it is - 1 megapixel AHD cameras, video recorders (old as a guard's joints) and a web of cables hidden under plaster.

What can be done here? First, let's figure out what new cameras for business can please you. We took several cameras from the "golden mean". There will be no super-megapixel solutions here, when you can watch the life of insects in the grass from a crane. We will show only those cameras that are taken from us for small businesses, gas stations, schools, car washes, summer cottages, hotels, parking lots, etc.

How to compare

Additional "buns" in the set of street cameras are usually not provided - a memory card / power cable comes with the "home" Nobelic / Oco2. The appearance of the cameras is standard for this class. The connection is identical (with one exception).|

There remains practically the only criterion (apart from price) - image quality.

The simplest and most affordable outdoor camera for 6,700 rubles. For this price, owners of small shops can get a turnkey security solution that controls a fairly large area.

It can be used not only outdoors, but also indoors. 72° viewing angle, IP67 water and dust resistant. It connects to the Internet both via Wi-Fi and Ethernet.
Operating temperature: from -30 to +50 degrees Celsius - will survive in the European territory of Russia.

The dimensions of the camera do not attract too much attention: 70 × 165 mm.

Supports video recording on MicroSD memory cards up to 128 GB. That is, you can record for free on the card, and watch the archive through the application wherever there is Internet.
Through the Ethernet port, it can be connected to a computer and watch video on any computer on the local network.

The camera has a corridor mode that allows you to clearly view long narrow rooms: the 3130F is conveniently located in the aisles between racks in warehouses and other similar places.

Nobelic 3130F mounts on any horizontal or vertical surface, and is also attached to the wall: all mounting accessories are included. Ease of installation and connection is another advantage for small businesses that cannot afford to spend extra money on an installer's visit.

Compact, powerful 4-megapixel outdoor camera, dimensions similar to the previous model (70×165 mm). The body of the camera is protected according to the IP67 standard. Operating temperature from -30 to +60 degrees Celsius. IR illumination up to 30 meters - the camera will capture a large area of ​​​​the territory even at night, when the watchman is already deeply asleep.

The camera can be powered from PoE (twisted pair) and from a 12 volt power supply - having a choice has the added benefit of less installation fuss and easier repositioning of the camera.

The resolution is twice as high as that of the Nobelic 3130F, the viewing angle is also larger, but the price has also increased - up to 11,990 rubles. For this money, you should get a solution that you don’t want to change in a few years. Let's not forget that the camera is not a loss for the enterprise, but a tool for making money. It will be strange if the camera after a while seems outdated, will not be able to perform its functions, and, therefore, be profitable. Let's check this thesis further, at the testing stage.

The interface, LAN connection, transfer of access rights to the camera, broadcasting to the public, full encryption of the video stream - all this is organized exactly like in all other cameras of the Nobelic series. We will not talk about this every time, but by default we mean it.

Nobelic NBLC-2430F Vandal Resistant

The only dome camera in the review. In addition, this camera is vandal-resistant, which is an additional plus on the street. A drunkard throwing a bottle at the camera will not cause a local video disaster.

The 4-megapixel 2430F features several noise reduction technologies and a wide dynamic range technology that allows you to get a normal image in conditions of sudden changes in lighting conditions.

The camera can be powered from PoE (over twisted pair) and from a 12 volt power supply.

Withstands temperatures from -30 to +60 degrees Celsius; differs in slightly less modest dimensions - 110 × 81 mm. But the larger the camera - and the viewing angle becomes larger: 106 °.

Nobelic NBLC-3230V-SD with varifocal lens

The varifocal lens allows you to adjust the focal length, thereby changing the viewing angles (99-37 °) and the scale of the selected viewing area. This allows you to look at different objects through the cloud interface. You don't have to travel 100 kilometers to the camera to change focus and see how a truck that decided to park in a secluded place is unloading.

The camera has a memory card slot so you can enable local video recording on a Micro SD card.

The Nobelic 3230V-SD supports twisted-pair power and can also be powered from a 12V power supply.

Chamber dimensions: 90.4 × 213 mm. Will survive harsh conditions: from minus 40 degrees to plus 60.
The price of the camera is 15,490 rubles - the maximum mark in the review, achieved due to the lens and reliability. Whether this amount is justified or not - we will check on the test.

Table of main characteristics

Support for the ONVIF protocol will appear later, currently under development.

Compare image quality

Comparison of all cameras at once at a distance of 8 meters with 8x zoom.

In the original resolution, if you do not zoom in, the picture looks like this. The shooting angle of each camera is noticeable.

More differences between cameras become noticeable at a distance of 15 meters. We zoomed in 12 times. Nobelic 3230V showed slightly worse results. The case when you need to look into the interface and fix the camera.

Original picture from four cameras. The only camera from the review that gives a clear image beyond 18 meters is the Nobelic 3430F.

conclusions

The Nobelic NBLC-3430F is on the other side of the scale of possibilities - the camera wins due to the high resolution of 2688x1520 and proves that the number of megapixels is not always of decisive (or equivalent) importance. The camera is suitable for monitoring large open spaces.

The Nobelic NBLC-2430F dome camera is only slightly behind - its resolution is the same as that of the 3430F, but the viewing angle is wider. Due to this, objects located in the center of the image appear slightly less clear. But more details are placed in the frame.

The Nobelic 3230V-SD camera stands apart. With all the declared characteristics, the camera is demanding on the user. Requires customization for a specific application, but this can be done without much difficulty.