Thermal Night Vision Camera

Thermal cameras are similar to home video cameras except that they make pictures by detecting and displaying tiny differences in heat, not light. Even the heat from a person’s hand on the wall leaves enough thermal energy behind to show up clearly to a Night Vision Camera.

So, does that mean that thermal imagers only let you see things that are hot? No. Everything generates thermal energy, even ice! And even though thermal energy is invisible to the naked eye, Night Vision Cameras detect it and turn it into video that is easy to understand, allowing you to see more, and see farther, than you ever could with your eyes.

When people talk about a thermal camera’s Resolution, they’re talking about the number of Pixels used to capture thermal energy. The bigger the number, the higher the camera’s Resolution. The higher the Resolution, the more Pixels you have gathering energy.

This means that a higher Resolution camera will typically let you see more detail, see smaller objects, and see them from farther away.

But how do they work? Well infrared is part of the electromagnetic spectrum, which the human eye can only see a small part of. We are able to detect visible light or radiation, whilst not seeing ultraviolet light at one end of the scale and infrared at the other (as per the second image on the right).

Infrared lies between the visible and microwave sections of the electromagnetic spectrum, with the primary source of infrared being heat or thermal radiation. So an object with a temperature above absolute zero (-273.15 degrees Celsius or 0 Kelvin) emits infrared radiation. Although our eyes can't see it, we can feel it on our skin. Even cold objects emit infrared radiation though the hotter the object, the more radiation it emits.

These thermal imaging cameras take the infrared energy from the object (A), focus it with the optics in the lense (B) and pass it onto the infrared detector (C) before sending it onto the sensor electronics in the back of the device (D). This then translates the data into an image which can be seen in the viewfinder. (Third picture on the right)

Thermal imaging also intensifies the image as it is not affected by the amount of light available, providing you with the clearest image even in the darkest conditions. THis works by detecting the heat being radiated by an object, putting it miles >Ahead of other technology such as Image Intensification, which amplifies small amounts of visible light thousands of times to get its image.