Fig.1.5 Masaccio, Tribute Money (ca. 1425). Brancacci Chapel, Church of Santa Maria del Carmine, Florence
In addition to rationalizing the representation of space
and providing an illusion of depth, perspective was often used to draw the
spectator's eye to the key figure or action in the painting.1 Take,
for instance, Masaccio's The Tribute Money (Figure 1.5). The slanted
lines representing the horizontal features of the building that recede into
the distance, often called orthogonals because they represent lines
in the scene that are orthogonal (Box 1.1) to the picture plane,
converge at a point known as the vanishing point for this perspective
construction (a concept explained in the next chapter). The vanishing point
falls slightly to the right Christ's head, thus drawing attention to the central
actor in the drama Masaccio has represented. In Piero della Francesca's Montefeltro
altarpiece (Figure 1.6), the vanishing point coincides with the Madonna's
left eye. In Leonardo da Vinci's Last Supper (Figure 9.9), the vanishing
point is centered upon Christ's head.
Fig 1.6 Piero della Francesca, Madonna and Child, Six Saints, Four Angels, and Duke Frederico II da Montefeltro (Brera altar-piece) (ca. 1472-4). Panel. Pinacoteca di Brera.
Fig 1.7 Domenico Veneziano, Martyrdom of Saint Lucy (ca. 1445). Panel. Gemäldegalerie, West Berlin
In other cases, such as Domenico Veneziano's (Figure Martyrdom
of Saint Lucy), the vanishing point coincides with a central locus of
the action rather than the head of the main figure: the hand of the executioner
that has just plunged a dagger into Saint Lucy's throat. In Raphael's Dispute
Concerningthe Blessed Sacrament (Figure 1.8), the vanishing
point coincides with the representation of the Host. In Raphael's School
of Athens (Figure ) the vanishing lines converge to where the aging Plato
is passing his accumulated knowledge to the young Aristotle.
Fig 1.8 Raphael, Dispute Concerning the Blessed Sacrament (1509). Fresco. Stanza della Segnatura, Vatican, Rome.
of orthogonal: Two intersecting straight lines, ι1
and ι2 are perpendicular if they form a
right angle at their intersection. Consider a line ι1
that intersects a plane S at a point P, and
suppose we drew a line ι2 in S through P.
If ι1 and ι2 are perpendicular, then ι1
is perpendicular to the plane S. The term orthogonal
was coined for a similar relationship that applies to line segments
or plane figures that do not intersect. Think of a plane figure
π and a line segment λ. When λ does not intersect
π, we can check whether the line, ι on which the segment
lies, and the plane, S, in which the figure lies, are
orthogonal. If ι is perpendicular to S, then p and
λ are orthogonal.
1 There is a tendency to think of paintings
as the representation of "one intercepted moment, a single instant"
(as Steinberg puts it), much like the "freeze frame" technique
sometimes used in films. In his analysis of Leonardo's Last Supper,
Steinberg (1973) has shown that there, as in other Renaissance paintings,
different parts of the picture depict moments that could not have occurred
concurrently. In his conversation with the sculptor Paul Gsell, August Rodin
gives another reason:
... while my Saint John is represented with both feet on the ground, it
is probable that an instantaneous photograph from a model making the same
movement would show the back foot already raised and carried toward the
other. ... It is exactly for that reason that this model photographed would
present the odd appearance of a man suddenly stricken with paralysis and
petrified in his pose ... . [Rodin1971 p. 74].