The Potential Pitfalls of Thermal Imaging
Thermal imaging is a tool used by many paranormal investigators. It can provide yet another method to record evidence. It can also be an extremely helpful when trying to locate warm-blooded animals, even extraordinary ones like Bigfoot.
Unlike your normal household camera which records in the visible light range, thermal imaging cameras record infrared radiation. Different levels of infrared radiation are emitted at different levels of heat. Therefore the camera allows us to see heat. Because this infrared radiation is always there, the cameras can work in full sunlight, complete darkness or anywhere in between. It is a very cool technology but investigators need to be aware of some of the pitfalls.
One of the biggest obstacles in owning a thermal imaging camera is the price tag. A quality thermal imaging camera with the ability to record starts around $1,000. Unfortunately these cameras have very low resolution and are limited for field environments. High-resolution thermal cameras can cost $3,000 – $30,000 depending on features, resolution and sensitivity!
Reflection and Absorption
Infrared radiation will reflect off of many shiny surfaces just like visible light. That means when your using your thermal imaging camera, mirrors, polished metal, even glossy paint will reflect surrounding infrared radiation back to you. An investigator can easily misinterpret their own infrared reflection as an apparition or entity. Also there are some materials that are treated to reflect infrared radiation but not visible light. Most modern windows have coating to block infrared light but allow visible light to pass right through. In essence these windows work like a mirror when you look at them with a thermal imaging camera: They will reflect the infrared radiation from everything behind you, including the radiation from your body!
Lastly be aware that some materials absorb infrared radiation very well. Matte finishes, black colors and some porous materials may appear “colder” relative to other objects in the room.
Differential Cooling and Heating
Unless you are in a climate controlled environment, virtually everything will be in some state of gaining or losing heat. During the day the sun heats up everything until sunset. Then at night the ground, trees, your backyard swing set all release heat and begin to cool. Different materials have different cooling rates. Aluminum is an excellent conductor of heat: It can heat up and cool down very quickly. Water is a thermal insulator: It takes quite a bit of time or heat energy to change the temperature.
As the outside temperature changes, the temperature of objects will change too, but all at different rates. Many metals will heat and cool much faster than the ground, wood or water. This means your thermal imaging camera will provide a different picture depending on the time of day, temperature, humidity, and wind speeds. This can make it difficult to compare thermal images at different times of the day: Different objects may appear colder or warmer relative to ground temperatures or another baseline. This could lead an investigator to believe some external, even paranormal force was the cause. Be careful with differential heating and cooling!
On a final note even coatings can play a big part in differential heating and cooling. Many modern paints and coatings can act as insulators, allowing them to absorb and release heat at a slower rate. For example a painted sheet of metal could have a number painted with a ceramic or rubberized coating. At certain times of day this number could appear warmer or colder than the surrounding metal because of the insulating coating.
Another huge issue with using thermal imaging is positive identification. Thermal images are typically low resolution, and seeing only the heat from an object makes exact identification difficult. A heat signature in the wood could be a bear or Bigfoot. Thermal imaging can be a good tool to guide investigators, but alone many thermal images don’t stand up to scrutiny.
Thermal imaging cameras can be a very useful investigation tool, but they can provide a lot of false positives if you don’t know what you’re looking at. As always be educated on what your instruments do. Waving a thermal imaging camera around with no concept of what you are recording does not produce good evidence.
I wish I could provide more details into the potential issues of thermal imaging but there isn’t a lot of information available on the topic. If I could get my hands on a good camera I would love to test it in various scenarios to demonstrate the capabilities and limitations of the system. If anyone has a thermal imaging camera they are willing to loan me for some research please let me know:)