You must have done this someday in your life, where you took your television remote and checked the infrared light coming out of it through a camera. You feel great when you do it for the first time, as it feels like some magic that you cannot see it with the naked eyes but the light is visible through the camera. Those who have not tried it yet, must try it right now and get the experience before reading any further as this post is about the reason behind it being visible only in the camera. Whenever we press the buttons of the remote, the infrared light travels to the appliance from the remote and that is how we control it.
In scientific words, the human eye sees the wavelengths between approximately 390 to 700nm, and Infrared light has a range of around 700nm to 1mm. The digital cameras can detect light outside the visible spectrum and that is why it can be seen in the camera. One of the Quora users wrote it to so that people can understand it easily, “Because the camera has a sensor that responds to IR as well as visible light. The electrical signal from the IR light is converted back to visible light by the LEDs (or LCD) on the phone’s screen. Since there is no color that we sense as IR, the camera designers just show IR as white. But the designers could have chosen a different color than white, maybe dark red- that might look better to us. Designers of thermal IR cameras do allow showing different intensities of IR as different colors.”
You can even see the infrared emitter through the camera that is on the front of the television. The emitter is what detects the infrared light passed from the remote to the television, and works according to the controls given. Sunlight has visible light, ultraviolet light, and infrared light as well, so when we use the camera to see the sunlight we can feel the difference in the lights coming from the Sun. If you haven’t tried it yet, then do it now and let us know about your experience in the comments section below.