How do I convert from radiance to reflectance?

The Living Optics camera captures spectral radiance as its nominal output. To convert to reflectance, the illuminant spectra is needed.

To estimate the illuminant spectra, place a calibrated white reference target in the scene (i.e. Tyvek or Spectralon target) and image it with the Living Optics camera.

During post-processing, reflectance is obtained by normalising the radiance spectra of a scene with the corresponding spectral radiance extracted from the white reference target.