The device comprises an aperture stop disc (1; 1') divided into a plurality of mutually exclusive filtering segments comprising a first (11; 11'), a second (12; 12') and a third filtering segment (13, 13'); the third filtering segment (13; 13') is adapted to pass a third portion of the spectrum (23) which is included in the portion of the spectrum passing the first and second filtering segments.;Due to third filtering segment, the aperture assigned to the color component corresponding to the third portion of the spectrum - preferably blue - is larger than the aperture assigned to the color component corresponding to the portion of the spectrum passing the first and second filtering segments.
展开▼
