Abstract: The invention relates to a method of observing and analyzing optical singularities, the method consisting in: illuminating the outside of the container by using a light-emitting surface (6) of axial symmetry around a vertical axis (Z) parallel to the axes of symmetry of the containers, with a property of the emission that is detectable by the acquisition system(s) (11) varying along a generator line of the light-emitting surface; for containers of low transmittance, taking the view image of the container portion by the image acquisition device receiving light beams coming from a portion of the light-emitting surface (6) situated on the same side of the container; or for containers of high transmittance, taking the view of the container portion by the image acquisition device receiving light beams coming from a portion of the light-emitting surface (6) that is diametrically opposite relative to the container.