X-Nico

unusual facts about image plane



Tin Mine Falls

If we additionally assume that the image plane is perpendicular to the ground plane (an imaginary plane Tangential to the surface of the Earth), and that the waterfall flows on a plane that is parallel to the image plane, we can estimate the height by measuring the vertical separation of waterfall head and base in


see also

Depth of field

Moritz von Rohr also used an object field method, but unlike Merklinger, he used the conventional criterion of a maximum circle of confusion diameter in the image plane, leading to unequal front and rear depths of field.

Point spread function

It can be shown (see Fourier optics, Huygens-Fresnel principle, Fraunhofer diffraction) that the field radiated by a planar object (or, by reciprocity, the field converging onto a planar image) is related to its corresponding source (or image) plane distribution via a Fourier transform (FT) relation.