It has been experimentally established that above a body surface a zone is formed in which light rays deviate in two different directions on both sides of the initial propagation direction. The efficiency of light diffraction has been found to decrease with distance from a screen and its edges and fractures. A portion of the light energy of the edge wave component propagating from the screen has been found to convert into the energy of the edge wave component propagating in the geometric shadow with the screen covered in soot. It has been demonstrated that the edge light is produced by rays deviated in the diffraction zone and by rays reflected from the screen edge, with the latter being conceptually a Sommerfeld edge wave component. It has been found that the phase shift between the fundamental and Sommerfeld components of edge light results in their amplification on illuminated side and attenuation in the shadow to the extent that total values of flux of the edge rays propagating on both sides of a shadow boundary of a thin weakly absorbing screen turn out to be approximately equal. The effects of thickness, shape, and absorptivity of the screen on the edge light have been estimated. The hypothesis that the wave amplitude diffuses through the light wave front has been demonstrated to be false.