Today, the technology is used by all combat and reconnaissance branches of the military and many police forces – so it is frustrating when Hollywood botches it up. Here are 6 misconceptions in depiction of thermal imaging in Hollywood that intelligent viewers should be aware of.
1. “Switching to thermal”
There are many weapon scopes for marksmen and snipers which employ TI technology. However, very few of them incorporate both day scope and a thermal imager. In many cases the scope would be standalone and would require the sniper to remove the existing day scope and replace with the Thermal one. Some products are clip-ons in which case they would be placed in front of the day scope without removing it. But it wouldn’t be a click of a button and would still take the guy about a minute to get an image which by that time – the aliens would be shredding the good guys to pieces.
2. Thermal in color
If this point was unclear – thermal technology does NOT see colors. All colors in thermal imaging are cosmetic. We decide that red is hot, and blue is cold, but we could just as easily use yellow to define cold or pink for hot. The pallet is completely the choice of the manufacture. In fact, most thermal imaging used for defense or security – don’t have color pallets at all and are just grayscale (as opposed to civilian uses). Probably because it’s less confusing for a user who is mostly interested in detecting hot objects like people or vehicles which may be a threat. It may be less pretty – but pretty isn’t the goal here. Almost all the cameras out there today have a Polarity option which allows to switch between Black-hot and White-hot.
3. “The cooling-disappearing body”
This I actually came across in a video game. When an enemy was shot down – via the thermal weapon sight, the body would then cool down in front of your eyes for a few seconds and gradually disappear. Makes sense, since thermal sees heat, right? Wrong! Algor mortis, the stage when a body gets cold only begins after an hour. During the first hour the body loses approximately 2 degrees and then another degree for every hour until it reaches the surrounding temperature. Obviously, this is affected by the environment, but you can assume it would take a few hours for the body to reach its surrounding temperature, and even then, you need to remember that thermal imaging also sees the substances differently, so a dead human may even appear in a thermal image way after her cools.
4. Residual heat signatures
In the movie Sicario there is a sick fight scene in tunnels under the border – the whole scene is shown in night vision and in thermal. In fact, director Stefano Sollima gets top marks for realism in this scene and I was debating whether to include it in my list. However, in one scene the guy wearing the thermal monocular on his helmet is following the heat signatures left by the footsteps of the guy before him. Now, I’m not saying it’s impossible to see footsteps in thermal – but the ground would have to be pretty cold and that foot would have to be pretty hot to leave a signature. Also, it would have to have been in place for 10-20 seconds to leave a heat signature which would last and be as clear as it appears in the movie.
Can thermal work like an x-ray machine allowing you to see a concealed weapon? Not really. It’s simple if you think about it. We wear clothes to protect us from the cold and isolate our body temperature (and avoid getting arrested for public nudity). Those clothes would do the same for a hand gun or bomb. Only if the difference between the body temperature and the object was extreme would you be able to see a difference, and even then, it would be more a general blob of slightly different coloration (not to mention rather uncomfortable!). Also, every additional layer of clothing would make the heat transference to the surface more difficult. So while you could potentially see a gun hidden under a t-shirt, add a jacket and it makes it even harder. Also-also, the airgap would add another level of difficulty in identifying the object as the heat transference would be very weak. So you’d need to press the fabric against the weapon – which would allow us to identify it with our visible light anyway.
My all-time favorite. For some reason, Hollywood has been convincing enough with this little fib, that I get asked about this a lot from customers. I guess movies and video games have been showing this nonsense for years. To be perfectly and unequivocally clear – Thermal CANNOT see through walls. In fact, it can’t actually see through windows unless that window is made of Germanium (which would be pretty damn expensive). There is technology that has the capability to see through walls, but doesn’t give any type of clear image or an image at all and requires the user to stand very close to the wall – but it’s not thermal. Before you start posting links of cameras being are used for inspection or maintenance, let’s remember that those cameras are only seeing the surface temperature being transferred to that point on the wall. We can use such cameras for maintenance and none-destructive testing – but we’re not going to be seeing any terrorists behind that wall.
Despite my rant, I imagine some of the items above will become incorrect in the future, as companies keep developing the technology. We can do science today which would have been science-fiction less than a decade ago. It’s an ever-evolving technology, and Opgal is proud to stand shoulder to shoulder with other competitors who are pushing the technology further every year.