[ Beneath the Waves ]

Thermal Imaging Examples

article and photographs by Ben Lincoln


In 2014, I finally obtained a thermal imager after Mike Harrison and several other EEVblog forum members discovered how to update the software on a FLIR E4 to give it the same resolution as the much more expensive E8. The E4 (~$980) is software-limited to 80x60, but could be uncapped to run at the sensor's native resolution of 320x240 like the E8 (~$4000) — however, as of July 2014, there is no mod/hack available to do this to newer E4 devices, so if you didn't take advantage of the opportunity between about November and May of 2014, you are unfortunately out of luck (for now?).

In any case, here are some of the more interesting examples I've found of objects or scenes that appear very different in this part of the spectrum.

Cars and Plumbing
[ Cars ]
[ Plumbing ]


[ Handprints ]
[ Fresh printout handprint ]
Fresh printout handprint

Hand- (and foot-) prints are one of my favourite examples of what thermal imaging can reveal. In the second photo, you can see that the effect is different when the surface has been pre-heated (in this case, by a laser printer).


In addition to handprints, footprints can also be captured under the right conditions:

[ Ghostly Footprints ]

Refrigerated Goods
[ Coffeemate ]
[ Half-and-half ]
[ Shopping bag ]
Shopping bag

Chilled objects can be especially interesting. Notice how the bottle of Coffeemate® and the carton of half-and-half aren't thermally transparent (you can't see what's behind them), but it is still possible to see the fluid level in each because it is cooling the container from inside. The thermal image of the shopping bag reveals where the glue used to attach the carrying handle is, in-between two layers of paper.

[ Downtown Seattle ]
Downtown Seattle
[ Fountains and frozen pillars in Las Vegas ]
Fountains and frozen pillars in Las Vegas
[ A homeless camp ]
A homeless camp
[ Museum of Glass ]
Museum of Glass

Thermal imaging of clouds at night creates an otherworldly effect. In the third image, a semi-infamous homeless camp in a wooded park is captured — the residents were completely invisible to the naked eye, but show up like lightbulbs in thermal wavelengths. That specific example made me realize why the military and police find these devices so useful.
The fourth image is of the Museum of Glass in Tacoma, Washington. Its central cooling tower apparently works very well.

[ Laptops ]
[ Monitors ]
[ Printers ]
[ Webcams ]
[ Various electronics ]
Various electronics

Just about any electronic device gives off a significant heat signature. Some LCD monitors' transformers and lighting systems give off so much heat that their shape can be seen through the case. Similarly, in the last photo, a Cisco switch whose cooling fan has been removed runs so hot that the locations of its major chips an also be seen from outside the casing.


Electronics generally show up so well on a thermal imager that I'm told they are used to sweep for hidden cameras and other surveillance gear.

Hidden Cameras
[ Hidden cameras (1/2) ]
Hidden cameras (1/2)
[ Hidden cameras (2/2) ]
Hidden cameras (2/2)

A room full of hidden cameras (part of the traveling Spy: The Hidden World of Espionage exhibit) has its difficulty level dramatically reduced with a thermal imager.

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