cam_focal_length   85 modules/dng.c  static int cam_focal_length[2]          = { 0, 1000 };
cam_focal_length  242 modules/dng.c      {0x920A, T_RATIONAL,   1,  (int)cam_focal_length},     // FocalLength
cam_focal_length  769 modules/dng.c      cam_focal_length[0] = get_focal_length(shooting_get_zoom());