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Let's place someone from the side
in front of a projector or an overhead projector turned on,
so that
his shadow can be distinguishable
on a projection screen or a white wall.
We hold a piece of paper
to an intermediate position between the individual and the screen,
and move it closer
until the edge of the sheet appears in the cone of light.
When we gradually
place forward the sheet in the light beam,
the shadow of the paper
gets regularly closer to that of the individual profile.
From a determined distance between the shadows
we can see that the shadows of the nose
and the chin are growing.
Indeed,
when the illumination of dark area
falls below a certain percentage of the illumination of lighted area,
the eye does not make any difference between dark area and lighted area.
between dark area and lighted area.
It follows on from
an obvious enlargement of the zone of the shadow.
Because of the fact that
the nose is closest to the piece of paper,
its shadow seems to be growing
whereas the head is not moving.
Production: University of Lille 1 - Sciences and Technologies
SEEM Multimedia Service - University of Lille 1
The Online Thematic University for Sciences
Teachers/ Researcher: Jean-Marie Blondeau, Bernard Bonnel
Project coordinator (shooting and editing): Bernard Mikolajczyk
Technician: Gerard Destrun
Voice over: Alain Nempont
Contact: semm@univ-lille1.fr