This is a spectrograph of the sun. The human eye is capable of seeing between 700nm and 400nm. So heres the question. If the digital camera is capable of seeing in the infrared spectrum which is above 700 then why didn't the camera capture anything above 700. The reason is most cameras have an infrared blocking filter that makes the camera less sensitive to infrared light. Since the camera made an exposure based on the visible spectrum it didn't record the IR because it isn't as bright. When you put on the Infrared filter all other light is blocked so it makes a longer exposure to capture the infrared.
Posted by Hello