Aims. The aim of the article is to show how the light curve of video-meteors can be described theoretically. Methods. The method of numerical integration of the system of differential equations describing the motion and ablation of a meteoroid during its atmospheric motion is employed. Results. We have shown that the modification of the ablation equation and the more general assumptions on the meteoroid cross-section behaviour can lead to a better description of light curves of faint video-meteors. The applied method indicates that the traditionally-used statistical parameter F could be replaced by another one, Levin's parameter μ, which has a physical meaning.