[en] In the emulsion chamber which are exposed at mountain altitudes a phenomenon called (optical) halo can be observed in the cores of high energy extensive air showers. A 'halo' is defined as an area of a few mm² of high optical density, which happens when a great number of charged particles go through a X-ray emulsion. In the present paper it is proposed to use a simple parameter: 'energetic' halo. It is shown that there is an evident correlation between the optical halo (observed in X-ray film) of the area exceeding 80 mm², the area of which was calculated by the use of the isodense method and the energetic halo