Infrared
From The Glossary of Digital Photography
A spectrum of light (electromagnetic radiation) not visible to the human eye. The wavelength of infrared is longer than that of visible light and appears on the electromagnetic spectrum near red light in the visible spectrum. Some digital cameras are sensitive to infrared and others can be modified to be so. Photographs made with infrared light are very empheral and other-worldly in their appearance. There are a number of uses for digital infrared imaging in medicine, science, and night-vision applications.
