Office de Radiodiffusion-Television Française. A stereo microphone configuration designed by the French national broadcasting system. This method calls for two cardioid microphones to be spaced 17cm (6.7″) apart, at an angle of 110˚. The 17cm represents normal ear spacing, and the 110˚ is to simulate the directional pattern of the ears. Recordings made using the ORTF method sound more open and spacious than those produced by the X-Y miking method. ORTF works well with headphone applications, but tends to sound somewhat dry and lacking in warmth due to the directional patterns of the cardioids, which pick up little ambient room sound. However, because of the close spacing of the microphones and the resultant similarity in phase, ORTF does provide mono compatibility, desirable in broadcasting. The Swedish equivalent is NOS, which is the same, except that the angle is 90˚ with a spacing of 30cm (11.8″) somewhat wider.