Continuous advances in the miniaturization of semiconductor technology allow nowadays fabrication of devices with performance exceeding the photographic techniques (nuclear emulsion). Single particle counting pixellated detectors open up a whole new field of possibilities in real-time detection and visualization of radiation and understanding its interaction in matter. Pixel detectors allows to visualize directly the ionization paths of different types of radiation, with additional energy and time information, even at very low fluxes which can be used for reconstruction of the incident radiation field