Abstract: In order to idealize the reflection model of object surface,the scene radiance of the Lambertian object illuminated by the strip light source,the uniform light source and the hemispherical uniform light source is derived by the radiance and the spherical triangle formula,and then the Lambertian surface reflection model in three kinds of light sources is obtained.

Key words: surface reflection model, lambert, light source, shape from shading algorithm, bidirectional reflectance-distribution function