While humans have decent enough eyesight in daylight, the fact remains we are simply not designed to be able to see in the dark. This is because we spend hour waking hours during the day, when it is light. Our sight is simply light bouncing off the processing sectors in the eyes and sending a signal back to the brain. In the dark, with limited light, we are less efficient.
There are many animals with far greater night-vision ability than us. These are generally animals that come out at night – that are nocturnal – and they need that night vision to survive. Look closely at these animals and you will see they have larger pupils than we do – the aperture that lets in the light, that widens and closes as needed.
Technology has come a long way in helping us ‘see’ in the dark. You have probably seen films or TV series in which they depict the military using night vision headsets. These are very real, and use light to create an image. However, it is not a clear image – clear enough at short distances for a soldier to take decent aim – but one that is somewhat rudimentary.
The other form of night vision is rather different; this is thermal imaging. How do thermal imaging cameras work? Let’s have a look at what it’s all about.
Thermal Imaging Explained
There is a fundamental difference between standard night vision equipment and thermal imaging cameras. The former uses the light spectrum and complex optics to create an image that is interpreted by the user. This is a viable method in many cases, but in some it is simply not enough.
Thermal imaging cameras work on a different principle. Put it simply: everything gives off heat. If we take 0-degrees as the baseline, anything above that will register on a thermal imaging camera to some degree. This is because, rather than looking for the light, this type of camera looks for the heat signal – in the infra-red spectrum – and converts this into an image.
To go into a little more detail; the camera consists of a very clever lens system that focuses the infra-red light that all objects in its field of view are emitting. It then transmits this information to an array of many tiny receptors, which in turn create a pattern.
This pattern – called a thermogram – is displayed in various different colours, which indicate different levels of heat. Therefore, the use can see where the objects that are emitting the greatest heat – living things and artificially heated elements – are within the image, and can also see them moving.
You may have seen a thermal image on TV, perhaps from a police helicopter search in which they are used to track people from above. This is largely what the user sees – and it is a very useful tool for many different types of user. If you are in need of one – turn to Thermal Imagers for a recommendation.
Who Uses Thermal Imaging?
Thermal imaging cameras are widely used by the military and security services. They are very useful in finding people at a distance, and even those hiding in some situations. These cameras are also used in industry. For example, if you have heat loss in your insulation, a thermal imaging camera can easily pick up precisely where it is being lost, so that the problem can be rectified.
The technology used in thermal imaging devices has come a long way in the last few years, to the extent that there are now inexpensive models that you can buy off the shelf, so if you think this may be of use to you, check them out right away.