Difference Between Dominant and Peak Wavelength 

Dominant and Peak Wavelength

Dominant wavelength is the single wavelength that is perceived by the human eye, and is defined as the wavelength of monochromatic light that has the same apparent color as the light source. Simply stated, if the color of a single wavelength ("X" nm) is indistinguishable from the color of a given LED, then that LED has a dominant wavelength of "X".

Peak wavelength is defined as the single wavelength where the radiometric emission spectrum of the light source reaches its maximum. Simply stated, it does not represent the perceived emission of the light source by the human eye, but rather by photo-detectors.