[photogrammetry]
In imagery, the apparent distortion of the top of a three-dimensional or vertical photograph in relation to the nadir point; specifically related to vertical images collected from a pinhole sensor where there is apparent displacement of objects that have elevation related to their base. The direction of displacement is radial from the principal point on a true vertical, or from the isocenter on a vertical image distorted by tip or tilt. Often referred to as building lean.
