Resumen
The invention can be used to measure the topography of surfaces of a transparent or translucent substrate (22) through which light can pass. According to the invention, a reference surface (241) having a known topography is moved closer to the surface (221) being studied. The intermediate space is filled with optically absorbent fluid (23) and the assembly is illuminated with a wide source (15) in which it is possible to differentiate at least two spectral bands with different absorption in the fluid (23). The quotient of integrated radiances in these spectral bands is not dependent on the point of the source or on the direction of observation. The recording of images (32) of the light transmitted in said spectral bands and the subsequent analysis thereof can be used to obtain the full profile of the surface (221) being studied.