Human observers are sensitive to the ‘(physical) light field' in the sense that they have
expectations of how a given object would appear if it were introduced in the scene in front of
them at some arbitrary location. Thus the ‘visual light field' is defined even in the ‘empty space'
between objects. In that sense the light field is akin to visual space considered as a ‘container'.
The visual light field at any given point can be measured in psychophysical experiments through
the introduction of a suitable ‘gauge object' at that position and letting the observer adjust the
appearance of that gauge object (eg through suitable computer rendering) so as to produce a ‘visual
fit' into the scene. The parameters of the rendering will then be considered as the measurement
result. We introduced white spheres as gauge objects at various locations in stereoscopically
presented photographic scenes. We measured the direction (‘direction of the light'), diffuseness
(‘quality of the light' as used by photographers and interior decorators), and intensity of the light
field. We used three very different scenes, with very different physical light fields. The images
were geometrically and photometrically calibrated, so we were in a position to correlate the
observations with the physical ‘ground truth'. We report that human observers are quite sensitive
to various parameters of the physical light field and generally arrive at close to veridical settings,
although a number of comparatively minor systematic deviations from veridicality can be noted.
We conclude that the visual light field is an entity whose existence is at least as well defined as
that of visual space, despite the fact that the visual light field hardly appears as prominently in
vision science as it does in the visual arts
Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.