A method for determining, in a natural posture in which the Frankfurt plane PF is substantially horizontal, at least one geometric/physiognomic parameter associated with the mounting of an ophthalmic lens in a spectacle frame intended to be worn by a wearer, comprising the following steps: a) capturing at least one substantially frontal image of the wearer's head , b) determining a measured value (Am) of an angle of inclination (A) of the wearer's head , during the capture of the substantially frontal image, which depends on the inclination of the wearer's head about a main axis perpendicular to a sagittal plane of the wearer's head, c) the wearer's head being placed in said natural posture in which the Frankfurt plane PF is substantially horizontal, determining a reference value (Aref) of said angle of inclination (A) corresponding to said natural posture of the wearer's head , and d) determining said looked-for geometric/physiognomic parameter on the basis of the substantially frontal image captured and as a function of the difference between said measured value (Am) of the angle of inclination (A) determined in step b) and said reference value (Aref) of said angle of inclination (A) determined in step c), characterized in that , in step c), the following steps are carried out: c1) capturing, in a manner that is not simultaneous to the image capture of step a), at least one substantially profile image of the wearer's head placed in said natural posture, the wearer's head comprising at least one profile indexing element positioned in such a way that it is identifiable on said substantially profile image of the wearer's head, c2) identifying, on said substantially profile image, the image of this profile indexing element, c3) determining a geometric characteristic of the image of this profile indexing element, and c4) determining said reference value (Aref) of said angle of inclination (A) corresponding to said natural posture of the wearer's head as a function of said geometric characteristic determined in step c3). a) capturing at least one substantially frontal image of the wearer's head , b) determining a measured value (Am) of an angle of inclination (A) of the wearer's head , during the capture of the substantially frontal image, which depends on the inclination of the wearer's head about a main axis perpendicular to a sagittal plane of the wearer's head, c) the wearer's head being placed in said natural posture in which the Frankfurt plane PF is substantially horizontal, determining a reference value (Aref) of said angle of inclination (A) corresponding to said natural posture of the wearer's head , and d) determining said looked-for geometric/physiognomic parameter on the basis of the substantially frontal image captured and as a function of the difference between said measured value (Am) of the angle of inclination (A) determined in step b) and said reference value (Aref) of said angle of inclination (A) determined in step c), c1) capturing, in a manner that is not simultaneous to the image capture of step a), at least one substantially profile image of the wearer's head placed in said natural posture, the wearer's head comprising at least one profile indexing element positioned in such a way that it is identifiable on said substantially profile image of the wearer's head, c2) identifying, on said substantially profile image, the image of this profile indexing element, c3) determining a geometric characteristic of the image of this profile indexing element, and c4) determining said reference value (Aref) of said angle of inclination (A) corresponding to said natural posture of the wearer's head as a function of said geometric characteristic determined in step c3). <EOS>