Spectral matching factors for starlight and full moon illumination conditions, GaAs and multialkali photocathodes, and some commonly encountered objects are computed and compared. For the S251 photocathode, these factors for combinations of dark green paint, green vegetation, and rough concrete are 0.27, 0.13, and 0.23 in clear starlight conditions and 0.55, 0.28, and 0.49 in full moon conditions, respectively. For the S252 photocathode, the former are 0.57, 0.48, and 0.56 and the latter are 0.72, 0.68, and 0.72. Finally, for the GaAs photocathode, they are 0.58, 0.65, and 0.61 and 0.45, 0.69, and 0.52, respectively. These values can be used for realistic estimates of the field performance and to optimize the design of night vision systems.