What Is a Thermal Camera?
Updated: Apr 19
Thermal imaging cameras, also called infrared (IR) cameras, detect heat naturally given off by objects, animals, or people. Thermal imaging cameras have lenses, just like any other camera, but in this case the lens focuses only on heat waves present in objects. Thousands of sensors convert the energy readings into an electrical signal which creates a video image forming a “thermal profile”. The hotter a subject is, the more heat it produces. Thermal cameras can see this heat and convert it to an image we can then see with our eyes. Cooler temperatures appear as shades of blue, purple, or green, while warmer temperatures appear as shades of red, orange, or yellow.
Thermal cameras are commonly used to observe and film the nocturnal activity of wildlife. Rare animals and never-before-seen footage of animal behavior have been captured using this type of camera. Even in daylight, thermal cameras can be used to help locate wildlife that may be well camouflaged behind shrub vegetation.
Why do thermal imaging cameras work better in the dark?
Since the ambient temperature at night (and importantly the temperature of unheated objects and the center of the environment) is much lower than during the day, thermal imaging sensors can show warm areas with higher contrast in the dark which makes them easier to see.
Focus and be Still!
Whether you’re just learning to use a thermal camera or you’re an expert thermographer, you’ve probably heard the mantra “Focus First!” The rationale is simple: of all the settings that can be adjusted, FOCUS is by far the most important way to improve thermal camera accuracy.
Focus is essential to both image quality and temperature accuracy in thermal cameras. A blurry or out-of-focus thermal image can produce a temperature measurement that’s off by as much as 20 degrees…perhaps more. That significant temperature difference will lead you to an incorrect conclusion. So it is very important to remember to keep the camera still!
Stationary vs. Movement
A moving heat signature at night is quicker to identify than a stationary one. Yes, thermal heat signature devices have some disadvantages. One of them is that they can not focus while being moved or focus on moving objects very well, unlike night vision devices, which experts recommend to those who want to conduct long-term research observation of a certain location.
So calm your breathing, be still, relax, FOCUS your thermal camera, and enjoy the view!