Abstract
The colour specification in the polychromatic point-spread function leads to the integration for each primary colour of the monochromatic point-spread functions, taking account of the spectral emission of the source and the spectral response of the receiver. A numerical technique for the off-axis object point has been programmed. The colour variation on the off-axis image in the presence of the primary aberrations is discussed in terms of the illuminance and the chromaticity, and it is compared with that of the aberration free system. The study has been done for the standard observer (CIE 1931). Different correction types of transverse chromatic aberration, the most influential one on the chromaticity variation of the image, are studied, and the relation between the shape of this residual aberration curve and the quality of the image with respect to the illuminance and the chromaticity are shown. Simultaneously the influence of the spectral distribution of the source is shown.