Google’s Pixel 4 features a couple of infrared cameras, a dot projector and a flood illuminator for the handset’s face unlock feature. However, even though the phone has these IR cameras, they typically can’t take pictures.
However, the HedgeCam 2 app from the Play Store changes things. The app, based on Open Camera, allows the functionality of taking pictures with the infrared camera. To enable the infrared camera, first tap the in-app button to switch to the front-facing shooter and then tap it again to start using the infrared camera.
According to 9to5Google, which first discovered the feature, the resolution is limited to 640 x 480, so the resulting quality isn’t the greatest.
It’d be interesting to be able to see the infrared dots by using the infrared camera; however, when using the HedgeCam app you can’t also use the face unlock functionality. 9to5 points out that if a user has two Pixel 4’s they could use one to record, while the other unlocks with face unlock to see the IR dot projector work in real-time.