Parallax

:This article is about parallax, the perspective shift. For the DC comic book character see Parallax (comics).

Photogrammetric parallax

Aerial photograph pairs, when viewed through a stereo viewer, offer a spectacular stereo effect of landscape and buildings. High buildings appear to 'keel over' in the direction away from the centre of the photograph. Measuring this effect, also called parallax, allows one, if the flying height and the distance between the aircraft's exposure locations is known, to deduce the building's height.

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