Recording a camera with IR lighting can save between 20% and 40%, generating a significant economic effect compared to a camera with conventional lighting.
Diego Madeo*
When designing a CCTV system, we must take into account several factors, since the performance will depend not only on the camera and the lens, but also on the quantity, quality and distribution of the available light.
In this sense we must analyze the existing light for each scene in the place and work on this parameter that, until a few years ago, was not given too much importance in a CCTV system. Next, the main characteristics of infrared illuminators and the economic impact of their correct use in the system will be described.
Before we start developing the main features of lighting for CCTV systems, let's look at some electromagnetic theory.
The first thing to consider is that there are different types of electromagnetic radiation, a broad spectrum that goes from radio frequencies to gamma rays. To understand we will concentrate on a portion of the electromagnetic spectrum that ranges from infrared radiation through visible light and even ultraviolet (UV) radiation.
The visible spectrum is a very small range from the wavelength corresponding to the violet color (approximately 400 nanometers) to the wavelength corresponding to the red color (approximately 700 nm.). The human eye can only detect light between 400 nm. and 700 nm.
For example, if you take remote control of your TV, the infrared light beam of the LED that transmits the commands to raise the volume or to change the channel is invisible to the human eye, since it is greater than 700 nm.
But if you take that same remote control and point it at a camera that detects infrared, it will detect the signal from the remote control and you can see this LED light on the display screen.
Although to generate images most day/night cameras use the light of the scene from environmental sources that generate visible light in the form of photons, such as the light of the moon or stars, we must bear in mind that there are cases where there is not enough light available, therefore, the scene suffers consequences, thus producing images of poor quality and visibility.
Visible vs infrared illumination
Depending on the type of application, we can use visible or infrared lighting. In the first case the images have a very good performance, instead the active infrared produce more detail for the same scene improving the functionality of the camera remarkably, being ideal in applications for night images with numbers and letters.
On the other hand, if the camera has analysis of video content, the images in the dark will be seen in a sharp and not "grainy" way, allowing the alarms to be triggered correctly. Keep in mind that if the video is of poor quality, false alarms will occur; or worse, they will not occur when necessary.
If we combine IR lighting with IVA (Intelligent Video Analysis), we ensure exceptional performance for alarm detection and management.
On the other hand, with the installation of infrared light we eliminate the need for visible light, which requires much more energy and a higher cost of operation and maintenance.
There are several advantages and benefits that arise from using IR lighting. On the one hand, infrared lighting in a lightless environment will drastically improve video quality and detection capability without generating environments contaminated by visible light.
On the other hand, in case of more demanding needs in terms of detection distances, you can operate with long-distance illuminators, but if we have difficulties to get energy for lighting, the ideal will be to install thermal cameras; for example, this type of camera detects and identifies passive movement of intruders more than 1000 m away.
Basically, thermal technology captures the heat emitted by bodies and in turn detects differences in temperatures. It also captures images both day and night, allowing vision through fog, "light" rain and smoke.
In addition, failures can be prevented by detecting overheating in certain situations, such as in engines or turbines.
Visible lighting for security
For those applications that require accurate color reproduction at night, a visible deterrent effect, support for security personnel during intrusive situations and optimization of camera performance, Bosch white light illuminators are a quick and easy installation solution.
In some cases, the use of visible white light acts to stop possible criminal acts. Those environments in which the lighting is continuous or activated by means of a motion sensor, have a tendency to scare the intruder or unauthorized personnel. Thus, a way to effectively deter is achieved.
Additionally, visible light illuminators have low power consumption and instant ignition, making them ideal for replacing conventional illuminators.
Benefits of incorporating IR into IP cameras
If day / night cameras are used we will obtain clean and good quality images, but in turn, these cameras must make a great internal effort to make continuous adjustments, thus causing a high consumption of bandwidth.
With the help of an active infrared illuminator the image should not be strained to compensate for the effects of noise in the image.
Noise, or deformation in images with low compression and high bit rate, congests the entire network and requires large storage spaces. This is a consequence of compression algorithms failing to interpret the difference between noise and the specific detail of an image.
Some of the tests performed yielded the following baseline results:
The file size of a Dinion camera during a normal scene is 2,165 kbps. When the lights go out, the camera goes into night mode, adapting to the low-light environment, using the sense-up to achieve the best possible image in this type of lighting.
Even though the image is black and white, the file size is now 2,750 kbps; this is caused by the grainy video which is actually noise produced by the camera's gain amplifier when trying to compensate for the low light level.
Then adding an IR illuminator to the scene, it improves considerably and reduces the file size to 568 kbps, in addition to the fact that it is an image with more detail and less distortion.
If you want to calculate the savings in bandwidth, you will get a saving of 75% as a result.
Depending on how many cameras are connected to the network, bandwidth savings can drastically reduce storage costs. This, in turn, will have a positive impact on the network.
For example, if we had an app with ten cameras in 1 lux, a storage requirement of 30 days at 4CIF and 25fps. without infrared illumination, the storage requirement is 15.1GB per camera every 12 hours. On the other hand, with infrared lighting and when calculating the storage both day and night, it results in a saving of 35% on the total recording.
Operational costs-benefits
The question is: How much money can be saved by using infrared illuminators? To answer this question we must compare the different light sources and their efficiency. We will compare in detail the costs of IR illuminators vs conventional lights. Finally, we will analyze the operational cost over five years.
Incandescent lamps (including halogen lamps) turn out to be very inefficient. Halogen lamps consume 85% of the energy in the form of heat, while normal ones up to 90%. In addition, its useful life is approximately five months, which will represent high maintenance costs.
Fluorescent lamps consume 60% of the energy in the form of heat. They have a longer service life than previous lamps: approximately, greater than five years.
On the other hand, HID (High Intensity Discharge) lamps are a little more efficient, since they have an energy expenditure of between 20% and 40% in the form of heat. However, they are not as popular because they have a long ignition time (two to three minutes) and, in addition, they cannot be turned on immediately after being turned off. Its shelf life is up to two years.
White light LED illuminators are extremely efficient. They only consume 10% of the energy in the form of heat and have lower operating cost. Also, its useful life is up to ten years. For their part, Bosch infrared LED illuminators have twice the range of white light.
Comparing halogen lights, HIDs and the Bosch illuminator, it is evident that there are considerable cost differences between the three light sources: the energy consumption of the illuminator accounts for only 9% of what halogen light consumes and 18% of what HID light consumes.
On the other hand, the total cost of ownership for an LED illuminator is $24 versus $392 for a halogen light. This represents a 94% difference in cost. All these calculations are based on 4,400 hours of use per year.
In conclusion, lighting for video surveillance systems will not only allow you to obtain better images but also a higher return on investment in electronic security, selecting the best product alternative.
And we must bear in mind that infrared illuminators do not disturb the artistic lighting of historical monuments, where low visible lighting is needed, places such as theaters, emblematic buildings which are taken care of at an aesthetic level, etc. The use of this technology will only be intended for security and surveillance.
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Bosch IR Lighting
The Bosch IR lighting system features the use of 3D asymmetric diffuser technology and Constant Light technology, which provides uniform illumination, balances close-up scenes with those in the background, eliminates hot spots and low exposure scenes.
Thus, it reduces the infrared intensity of objects near the illuminator and eliminates hot spots in the scene, poor lighting patterns and reduces wasted light.
In turn, Constant Light technology offers a constant level of infrared illumination throughout the operational life of the equipment. The video produced with this technology optimizes the performance in motion detection and video analysis software, by reducing grainy images, increasing image quality.
*Responsible for marketing and communications of Bosch for Latin America.
