The methods of illuminance calculation of optical system are systematically analysed in this paper and a valuable program are presented.The program could be used to calculate the illuminance of such systems as plane
sphere
2-D curved surface
multi-D axisymmtric curved surface and so on. The lens reflection and absorption
central shade
lense coating
spectrum distribution of light source are all considered in the program.In addition
the utility of illuminance algorithm in the field of chromaticity is put forward and discussed.