ANAMORPHOSES
(introduction 1)
The definition of perspective as intersection of the visual pyramid with a transparent
plane given by Alberti (or Leonardo) depends on a strictly mathematical
interpretation of vision. The visual pyramid (having the base in the observed objects
and vertex in the viewer’s eye) described in “De pictura" is a geometrical
abstraction that deliberately avoids taking into consideration the physical and
physiological complexity of vision, which was instead recognised by the theory of
optics in the Middle Ages (natural perspective) (1).
On the one hand, this implies a return to the principles of Euclid's optics (geometry of
rays) and on the other hand it generates conflicts and contradictions. When projecting
three-dimensional objects on the flat picture plane (artificial perspective), the
dimensions that these objects have on the image plane must be determined so that
proportions appear correct when looking with one eye from a fixed point of view. As
a consequence, it was within the study of elaborate methods to create perspective
drawing that the possibility of anamorphoses emerged. Distorted figures could be
produced without breaking geometric rules: if the viewer did not look at the picture
from the point of view the painter used for the projection, then the figure appeared
distorted and unrecognisable. For example, the "exaggerated" perspectives of the
rectangles in Figure 1 and Figure 2 are obtained through a classic procedure
(Barozzi's second rule), but the point of view and the distance point are in a "strange"
position (optical anamorphosis).
That is why, ever since the 15th century, theorists and practitioners have developed
rules according to which a viewer looking at a painting (with both eyes and from any
point of view) should have a harmonic
perception of space and proportions.
However, transgressions to those norms
became very popular in the 17th century.
The production of monstrous and horrible
images was carefully studied: reflection
and refraction were used in order to
produce deformation of figures and to
make their decoding more complex
(catoptic and dioptric anamorphoses).
Rational geometric rules were used in
order to produce “un-ruled” forms; order
was changed without being destroyed (2).
The diffusion of anamorphoses and the
interest in optical illusions was linked to
complex transformations in the culture.
The transformations relate to philosophical and religious reasons: crisis of the self,
who appeared to be lost in a homogenous space and no longer trusted his/her
sensations (Cartesian dilemma, vanity of the world, but also will to re-affirm the
presence and strength of laws by breaking harmony and going beyond what is deform
and confused); to practical and scientific matters: eliciting wonder and admiration
through scenic effects (banquets), but also showing the power of natural magic (as
opposed to Aristotelian physics); to aesthetic matters: evolution of Mannerism and
affirmation of the Baroque style (3).
New spaces were opened up, adding to the ones coming from the application of
perspective to (civil or military) engineering and to astronomical and cartographic
surveys. The separation between the theory of projections and of sections (of
prevalently mathematical interest) and perspective as a technical and artistic matter,
which contributed to establishing the autonomy of projective geometry, progressively
took place.
(1)
Bauer, Experimental Shadow Casting and the Early History of Perspective, The Art Bulletin,
June 1987 vol. LXIX, 2
(2)
Even if the principles underlying the construction of anamorphoses had been studied also in the
16th century, the first work discussing these is details is J. F. Niceron La perspective curieuse,
Parigi 1638, translated into Latin with the title Thaumaturgus opticus, Parigi 1646. Both versions
had numerous editions and had a large distribution.
(3)
Cf. J. Baltrušaitis, Anamorfosi e magia artificiale degli effetti meravigliosi, Adelphi 1978