The preferred term for the shorter wavelengths in the infrared region extending from about 0. 75 μm (visible red), to around 2 or 3 μm (varying with the author). The longer wavelength end grades into the middle infrared. The term really emphasizes the radiation reflected from plant materials, which peaks around 0. 85 μm. It is also called solar infrared, as it is only available for use during the daylight hours.