Method for observing an emission of light (14, 15) from a sample (10) in a medium (11) of refractive index nL disposed against a surface (20a) of a transparent support (20) of refractive index nS, greater than nL, the emission of light comprising luminous components oriented toward the support and forming an angle θ with a direction (20b) perpendicular to the surface (20a), said components including supercritical luminous components and critical or subcritical luminous components, the method implementing an observation device (100) capable of collecting at least part of the emission of light, of applying filters (170) to the luminous signal collected; and of transforming the filtered luminous signal into an image zone of the sample (6a, 6b); the method being characterized in that: A modulation of the filtered luminous signal is carried out, in which luminous components arising from the critical or subcritical luminous components of the emission of light are allowed to pass through so as to obtain image zones (6a, 6b) of one and the same region of interest of the sample, the modulation pertaining to all or some of the luminous components of the collected luminous signal which arise from the supercritical luminous components of the emission of light; and At least one useful image zone (6c) of the sample is produced by combining image zones (6a, 6b), the combination evidencing differences between the image zones (6a, 6b) related to the modulation.