The OnePlus 8 Pro comes with a fun extra "color filter camera" that processes infrared light in addition to visible wavelengths. With the help of some post-processing, it creates stunning and weird false-color images. That's not all there is to it, though. IR light is essentially electromagnetic radiation capable of penetrating certain materials other lightwaves can't, so the camera can be used for a neat party trick: It lets you see through some thin plastics and a few other materials.
As XDA Developers' Mishaal Rahman tweeted, the see-through effect is mostly visible with thin plastics, like in the YouTube video embedded above. It showcases how you can see through a remote. A Redditor also showed off some other images of another remote exposing text and the batteries hidden within it. Other Reddit users report that it's possible to see through some fluids like red wine and coke. IR light sources like a remote's LED also light up brightly when viewed through the color filter camera. The effect doesn't work for other plastics like the keyboard and parts of the camera in our sample further below, though.
Left: Regular image. Middle: Color filter camera image. Right: Back cover removed.
These eery images are a result of the camera's capability to capture infrared light. In fact, all cameras out there would normally retain infrared wavelengths in photographs, but they come with built-in IR filters that make results as close to our vision as possible. OnePlus' custom processing on top of both the infrared and visible light is probably the reason why its results don't look like mono-color images shot on certain film equipment or special night-vision cameras. There are also post-processed thermal photos that use colors visible to us to depict temperatures, which could be another possible application for the OnePlus camera if the company implemented that.
Not all materials become see-through due to the missing IR filter.
OnePlus' tech isn't something special and unprecedented in the consumer technology space, though. The Pixel 4 and the latest iPhones use IR blasters and cameras for biometric authentication, even if you can't take pictures with them. VR equipment like the Oculus Rift works with the same technology. There are even some old Sony camcorders that used to include an infrared night-vision mode.
It's neat that OnePlus allows us to use the technology as a party trick, though that's really all it is — I'd rather have an additional regular lens or a lower price tag than a camera that only works for extremely rare, specific purposes.