Abstract: A multi-wavelength active marker includes a first light source emitting a first wavelength of light, a second light source emitting a second wavelength of light different from the first wavelength, and a converging light-combining waveguide that is arranged adjacent the first and the second light sources. The waveguide guides the light emitted from the first and second light sources to a diffuser for concurrent emission of both of the first and second wavelengths from the diffuser. The multi-wavelength active marker may be used in co-calibration of disparate camera systems, such as a motion capture camera system and a cinema camera, which are not sensitive to the same wavelengths for calibration purposes.