ELI5 Why flash is seen on phone camera but not to a naked eye, when key of a remote control is pressed
In: Physics
Cameras usually have the ability to see in the IR spectrum. It’s limited and it’s usually blanked out by the visible light spectrum, but a remote has a bright IR light inside.
As other people have said, remotes use infrared (IR) light (which is the same as visible light, just with a wavelength outside the range that humans can see) which phone cameras can detect. Humans eyes cannot detect it, but part of the software that displays what the camera sees to the screen (sort of) converts it to light that’s visible to humans. This is likely because phone screens can’t display infrared light (only visible light), but the software forces it to show SOMETHING from the camera.
A camera can pick up the whole light spectrum whereas your eyes can now. Remotes emit infrared light which the human eye can not see.