How to Fake Thermal Imaging Video

It has tons of real world uses, and thermal imaging has started leaking into Hollywood as well. From Predator, to Stargate, even the Ghost Hunters on Sci-Fi, I'm sure everyone has seen thermal imaging video. I recently had need to create some thermal imaging video and began to research prices of cameras. I quickly discovered they were a lot more than I wanted to spend and looked into modifying a camcorder instead. I quickly discovered that wouldn't work either (more on that shortly), so I began playing around trying to make normal video look as if it were shot with a thermal imaging camera.

After glancing around the net for tutorials I came up blank. That's when I decided it was time to come up with the technique myself. Hopefully, someone else with the same problem will come across this instructable and save themselves the time it takes to figure this out.

Step 1 How Thermal Imaging Works

In order to properly fake thermal imaging video, I had to develop a decent understanding of what it was and how it worked. The electromagnetic spectrum consists of several sections including (in order of wavelength) radio, microwave, infrared, visible light, ultraviolet, x-ray, and gamma rays.

There are basically three ways for a camera to "see in the dark". Light amplification is the most commonly used method. It is really just the gain on a camera and tells the camera to increase the amount of visible light it is collecting when the light source is faint. Also common on consumer camcorders is the nightshot feature, which lights the area in front of the camera with infrared light which can't be seen by human eyes, but which the camera can see. It then converts what it sees into video in the same way it normally would. These images tend to be pretty desaturated with a tint of green. Think Blair Witch Project, and you'll probably have the right idea.

That leaves thermal imaging, which uses cameras that do not operate with CCDs (charge-coupled device). Instead most thermal cameras use a concept called FLIR (forward-looking infrared) that captures thermal radiation and creates an image based on temperatures. These black and white images are then assigned color values and our easily recognizable thermal images are created. FLIR isn't the only thermal radiation system, but I'm guessing it's the most common, and the one I studied to understand the process.

Comments

[daninja]

cool! me and my brother were going to do a nerf hitman movie and we needed to have thermal imageing!

[conrad2468]

I have this on my mac.......its based on light.....lol smile right when you take a pic and look @ ur grillz!

[yokozuna]

I've also since discovered final cut has a filter that can be customized in the same way as my photoshop gradient. I haven't had time to update the instructable, but Mac users with a copy could save themselves from the dreaded frame export/import scenerio. I'm guessing Avid and Premiere have something similar, just don't know where it is off-hand.

[joosh]

Great instructable. The only thing bad i can see is that white line messes up your thermal. Just have a random hot line in to grass. lol

[CameronSS]

It would be nice if you could figure out how to make the shadows darker than the grass...as it is, the shadows appear "warmer" than the grass, when they would actually be cooler (darker blue).

[yokozuna]

I see what you mean, but the purple color is actually supposed to be cooler than the blues. If you look closely at the gradient in step three, you should see what is really like a simulated temperature scale.

[CameronSS]

Oh, I see now. *smacks self in face* Nice job, I wasn't actually trying to be demeaning.

[yokozuna]

No worries- after I read your comment, the purple does appear brighter than the blue, and it's very understandable why someone would have seen it that way.

[Axel_Freelancer]

i thought that purple was warmer that blue cause the guy was lying on the grass, therefor transmining his heat.......but i got it wrong .... lol