Relation between focus and camera intrinsic parameters

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Does a focus tuning affect the camera intrinsic parameters? More precisely, if the focus of a camera is changed, does the camera intrinsic parameters matrix remain unchanged?

Apparently, since this matrix involves only the focal length, image sensor format, and principal points of the lens (see Wikipedia), it should not be changed by a focus tuning; but this is clear for me if the camera contains a single lens only; in general, a camera contains several lens, say 2, and the focus changes the distance between these two lens. So, if this pair of lenses can be seen as a single lens, what does prevent the focus tuning to modify the "intrinsic characteristics" of this equivalent lens?