The term night vision refers to the ability to see when there is not enough light. Usually, night vision is made possible by a combination of sufficient intensity range and sufficient spectral range. Sufficient intensity range refers to the ability of seeing objects in low light condition. It has been observed that humans have poor night vision as compared to most animals. This is largely because of the differences in the anatomy and morphology of their eyes. On the other hand, the spectral range techniques can sense the radiation that is invisible to a human observer. Their vision is restricted to a certain range of electromagnetic spectrum that is called visible light. In order to ensure improved vision in low light conditions, companies like Axton Technologies offer a wide range of IR illuminators.
The light spectrum is measured in the inverse or in the wave length, whichever is frequent. The wave length of light is measured in nanometers and one nanometer is equal to 1 x 10-9 meters. The visible portion of this spectrum is between 380nm to 750nm range. The day/night optical cameras are manufactured in a way so that these can observe a wider spectrum than the human eyes. These optical cameras perform better with the assistance of IR illuminators. In case there is very low illumination from the street lights or the moon, an IR illuminator can be used as a spotlight to use these cameras.
There are different types of IR illumination devices including LED light, laser type and filtered incandescent lamps. These are high power lamps that are covered by an infrared filter. It lets the infrared radiation pass and blocks the visible light component. LED illuminators utilize a group of standard infrared emitting LEDs. The laser types are the most efficient among IR illuminators. These devices are based on an infrared laser diode which produces near infrared energy.
As IR illuminators have several advantages over other night vision technologies, they have merged as the most in demand among a wide range of industries and businesses. Apart from being cost-effective as compared to other options, IR illuminators also offer better quality as they can perform high-speed video capture; see through darkness, mist, fog, rain and snowfall etc; and eliminate the inconsistency of ambient light. As the market has a growing demand for these, Axton Technologies brings a range of IR illuminators along with LED light and other professional lighting solutions for security and surveillance.
CCTV Cameras are a common thought when one thinks about security. IT is now becoming a common sight to see such cameras around homes, offices and also public places. Since these cameras need to work day and night and are supposed to capture all the movements that may occur within their range, it is necessary to make it efficient enough to capture things in the dark as well. The IR illuminators are devices that enable these CCTV cameras to capture images and videos that cannot otherwise be seen through a human eye. Let us see a few benefits of using IR illuminators and later IR LED lights along with CCTV Cameras.
- The term infra red specifies that it will help capture images even in the dark when things are not clear for the human eye.
- The infra red light is only visible to the camera and cannot be seen by anyone else. Thus making it suitable in areas where security is needed.
- Similar to the above advantages, an IR LED is also made up to help a CCTV capture images in the dark.
- The power consumption of these IR LED illuminators that are being used for CCTV cameras is comparatively low. Thus, it helps in saving the amount that would be spent on power bills.
- Although the LED lights are well known for their efficient light supply, the IR LEDs focus on maintaining security and hence one would not realize whether it is on or off.
- The use of IR LEDs with CCTV cameras is proved to be an efficient method that consumes less energy and is easy to be installed.
Thus, taking into consideration the other installation and power costs that you may have to bear while maintaining a security system; one can surely take the help of IR LED illuminators to save the further costs. Although this might not be the best solution to obtain security, this method proves to be better than simply installing a CCTV camera that will only record the movements during day time.
An Electronic sensor that senses infrared (IR) light emitted from objects such as IR Illuminators when found within a certain range is called a Passive Infrared Sensor or PIR sensor. PIR sensors are usually used in PIR based motion detectors in order to check the movement of an object.
Working of PIR Sensors
Every object that has a temperature above zero degrees emits energy in the form of radiations. This form of radiation is usually invisible to the human eye. It gets detected by devices that are specially designed to detect such kinds of radiations. The “P” in the PIR sensors stands for passive. This is because the sensor does not release any form of radiation or energy to detect objects. In fact, it detects the radiations emitted by the other object that may be within its field of view. Though these sensors do not have to emit any sort of energy, they are the most complicated sensors as compared to others like photocells. Let us go, through the basic of the actual working of a PIR sensor.
The Passive Infrared sensor has two main slots in it. Each of these slots is constructed in a way that they are more sensitive to IR lights. There is a lens attached in between. This lens helps in widening the area that is being detected. The two slots detect the slightest movement taking place within their reach. When the sensors are idle, i.e. there is no movement around the sensor, both the slots show the same amount of IR detected. When a warm body, such as a human or an animal comes closer to the sensor, one half of it is intercepted and this causes a positive differential change among the two slots. By the time the body moves out of the range, it causes a negative differential change.
PIR Sensors are useful in detecting minute changes in temperature as they can also detect radiations from Infrared Illuminators that are not visible to the human eye. It will prove to be helpful in detecting movements in areas where entry is restricted.
“Night Vision” mainly refers to a technology that provides vision in complete darkness and improves vision quality in low light environments. The two main methods that this technology is implemented in are low light imaging and near infrared illuminators. These two methods differ from each other in many ways. They both work in different ways and different equipments are used while implementing them.
Let us observe a few main differences between them.
- The Low light imaging technique makes use of Image Intensifiers and On chip gain multiplication cameras for the entire process. Whereas, the near infrared illumination technique requires the usage of IR illuminator that help in obtaining a finer and sharper image.
- As the low light imaging method makes use of the amplification method, it needs at least some amount of light in order to capture an image. The near infrared, on the other hand can perform well even during the night time mist, fog, rain and also snowfall.
- The low light imaging technology is usually used in the objects such as night vision goggles and night scopes that can be used for a better vision in low light. Near IR is used in the form of filtered incandescent lamps, LED type and the laser type illuminators. These are used along with night vision cameras to capture images even in the dark.
- An advanced feature that may not be observed using the low light imaging method is eliminating shadows and identifying letters, numbers and objects. All this is possible with the use of near infrared illuminators.
- Finally, speaking about the cost, the near infrared illumination method is the least expensive method that can be used for night vision.
The above mentioned points have clearly stated a few basic differences between the two methods. The main ones being the way they work, the results they give and cost of implementing each of them. The quality of the image intensifiers used in low light imaging can be further improved by using a near infrared illumination lighting. Thus we know that the image intensifiers and the latter method when installed together will deliver a better performance and a sharper image quality. Thus, no matter how well the low light imaging works, an additional near infrared light will always enhance its quality.