Television images become to be used for various fields as security observation in addition to broadcasting. It will be useful to install a camera system for security in order to obtain “restraint of a crime” and “criminal information”. In particular, it is demanded to obtain “face discrimination” as criminal information. However, on an outdoor situation in the nighttimes there are many difficulties to obtain the “face discrimination” images by CCD camera. It is important how to establish lighting conditions to obtain video-monitored images. The lighting conditions are prepared by diversely modelled visual targets based on Cuttle's modelling evaluation experiments as reference and evaluating the level of “face discrimination” on the monitor. We discussed descriptive method for modelling effect using the illuminance as parameter.