A novel technique has been developed for the quantitative study of vibronically-resolved transition intensities in polyatomic molecules beyond the Condon approximation. Matrix elements of coordinate-dependent transition moment operators are evaluated analytically with the pertinent vibrational wave functions obtained by means of Lie algebraic methods. Experimentally-observed S2O C?1A?-X?1A?(?*-?) emission intensities, in conjunction with previous Franck-Condon calculations, reveal pronounced non-Condon effects for vibronic bands terminating on higher-lying vibrational levels of the ground electronic state. The transition dipole moment is examined as a function of both the S-O and S-S local stretching coordinates. © 2000 American Institute of Physics.