8.1 Principles of linear perspective

Linear perspective revolutionized Renaissance art, creating the illusion of 3D space on flat surfaces. Artists used math to make objects smaller as they receded, with parallel lines meeting at vanishing points on the horizon.

Key elements include horizon lines, vanishing points, and orthogonal lines. These tools let artists craft realistic depth, influencing viewer perception and ushering in a new era of visual representation in painting and architecture.

Linear Perspective for Depth Illusion

Mathematical System for Three-Dimensional Illusion

• Linear perspective is a mathematical system used to create the illusion of three-dimensional space on a two-dimensional surface (paintings, drawings)
• Based on the principle that objects appear smaller as they recede into the distance
• Parallel lines appear to converge at a vanishing point on the horizon line
• Allows artists to create a sense of depth and space in their work, making objects appear to exist in a three-dimensional environment

Development during the Renaissance

• Linear perspective was developed during the Renaissance period
• Key figures such as Filippo Brunelleschi and Leon Battista Alberti contributed to its understanding and application in art
• Brunelleschi demonstrated the principles of linear perspective through his architectural drawings and paintings (Florence Baptistery)
• Alberti wrote a treatise on the principles of linear perspective, "De Pictura" (1435), which provided a theoretical foundation for its use in art

Elements of Linear Perspective

Horizon Line and Vanishing Points

• The horizon line is a horizontal line that represents the eye level of the viewer
• Typically placed at the viewer's eye height within the composition
• Vanishing points are points on the horizon line where parallel lines appear to converge in the distance
• A one-point perspective system uses a single vanishing point, typically placed near the center of the horizon line
• A two-point perspective system uses two vanishing points, often placed at the edges of the composition, to create the illusion of objects receding in two directions
• A three-point perspective system adds a third vanishing point, either above or below the horizon line, to create the illusion of objects receding in three directions (dramatic or exaggerated effects)

Orthogonal and Transversal Lines

• Orthogonal lines are lines that are perpendicular to the picture plane and recede towards the vanishing point(s)
• Represent the edges of objects or architectural features
• Transversal lines are lines that are parallel to the picture plane and perpendicular to the orthogonal lines
• Represent the horizontal edges of objects or architectural features
• The combination of orthogonal and transversal lines creates a grid-like structure that helps establish the illusion of depth and space (tiled floors, buildings)

Linear Perspective and Viewer Perception

Horizon Line Placement and Vanishing Points

• The placement of the horizon line in a composition can affect the viewer's perception of the scene
• A low horizon line creates a sense of monumentality (grandeur, importance)
• A high horizon line creates a sense of depth and distance
• The number and placement of vanishing points can influence the viewer's perception of the space
• Multiple vanishing points create a more complex and dynamic sense of depth (cityscapes, interiors)

Convergence of Lines and Sense of Depth

• The convergence of orthogonal lines towards the vanishing point(s) creates a strong sense of depth and space
• Leads the viewer's eye into the distance and emphasizes the three-dimensionality of the scene
• The use of linear perspective can create a sense of order and rationality in a composition, reflecting the Renaissance interest in mathematics and science
• Artists can manipulate the use of linear perspective to create specific effects (exaggerating depth, creating a sense of unease or instability through distorted or inconsistent perspective)
• Examples of manipulated perspective can be seen in the works of artists such as Paolo Uccello ("The Battle of San Romano") and Giorgio de Chirico (metaphysical paintings)