In visual perception, an optical illusion is an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality. Illusions come in a wide variety; their categorization is difficult because the underlying cause is often not clear but a classification proposed by Richard Gregory is useful as an orientation. According to that, there are three main classes: physical, physiological, and cognitive illusions, and in each class there are four kinds: Ambiguities, distortions, paradoxes, and fictions. A classical example for a physical distortion would be the apparent bending of a stick half immersed in water; an example for a physiological paradox is the motion aftereffect. An example for a physiological fiction is an afterimage. Three typical cognitive distortions are the Ponzo, Poggendorff, and Müller-Lyer illusion. Physical illusions are caused by the physical environment, e.g. by the optical properties of water. Physiological illusions arise in the eye or the visual pathway, e.g. from the effects of excessive stimulation of a specific receptor type. Cognitive visual illusions are the result of unconscious inferences and are perhaps those most widely known.
Installation art is an artistic genre of three-dimensional works that are often site-specific and designed to transform the perception of a space. Generally, the term is applied to interior spaces, whereas exterior interventions are often called public art, land art or art intervention; however, the boundaries between these terms overlap.
Op art, short for optical art, is a style of visual art that uses optical illusions.
Forced perspective is a technique that employs optical illusion to make an object appear farther away, closer, larger or smaller than it actually is. It manipulates human visual perception through the use of scaled objects and the correlation between them and the vantage point of the spectator or camera. It has uses in photography, filmmaking and architecture.
Trompe-l'œil is an artistic term for the highly realistic optical illusion of three-dimensional space and objects on a two-dimensional surface. Trompe l'œil, which is most often associated with painting, tricks the viewer into perceiving painted objects or spaces as real. Forced perspective is a related illusion in architecture.
Uta Barth is a contemporary German-American photographer whose work addresses themes such as perception, optical illusion and non-place. Her early work emerged in the late 1980s and 1990s, "inverting the notion of background and foreground" in photography and bringing awareness to a viewer's attention to visual information with in the photographic frame. Her work is as much about vision and perception as it is about the failure to see, the faith humans place in the mechanics of perception, and the precarious nature of perceptual habits. Barth's says this about her art practice: “The question for me always is how can I make you aware of your own looking, instead of losing your attention to thoughts about what it is that you are looking at." She has been honored with two National Endowments of the Arts fellowships, was a recipient of the John Simon Guggenheim Fellowship in 2004‑05, and was a 2012 MacArthur Fellow. Barth lives and works in Los Angeles, California.
Aerial perspective, or atmospheric perspective, refers to the effect the atmosphere has on the appearance of an object as viewed from a distance. As the distance between an object and a viewer increases, the contrast between the object and its background decreases, and the contrast of any markings or details within the object also decreases. The colours of the object also become less saturated and shift toward the background colour, which is usually bluish, but may be some other colour under certain conditions.
The term composition means "putting together". It can be thought of as the organization of the elements of art according to the principles of art. Composition can apply to any work of art, from music through writing and into photography, that is arranged using conscious thought.
Illusionistic ceiling painting, which includes the techniques of perspective di sotto in sù and quadratura, is the tradition in Renaissance, Baroque and Rococo art in which trompe-l'œil, perspective tools such as foreshortening, and other spatial effects are used to create the illusion of three-dimensional space on an otherwise two-dimensional or mostly flat ceiling surface above the viewer. It is frequently used to create the illusion of an open sky, such as with the oculus in Andrea Mantegna's Camera degli Sposi, or the illusion of an architectural space such as the cupola, one of Andrea Pozzo's frescoes in Sant'Ignazio, Rome. Illusionistic ceiling painting belongs to the general class of illusionism in art, designed to create accurate representations of reality.
Anamorphosis is a distorted projection that requires the viewer to occupy a specific vantage point, use special devices, or both to view a recognizable image. It is used in painting, photography, sculpture and installation, toys, and film special effects. The word is derived from the Greek prefix ana-, meaning "back" or "again", and the word morphe, meaning "shape" or "form". Extreme anamorphosis has been used by artists to disguise caricatures, erotic and scatological scenes, and other furtive images from a casual spectator, while revealing an undistorted image to the knowledgeable viewer.
Shahzia Sikander is a Pakistani-American visual artist. Sikander works across a variety of mediums, including drawing, painting, printmaking, animation, installation, performance and video. Sikander currently lives and works in New York City.
Phantograms, also known as Phantaglyphs, Op-Ups, free-standing anaglyphs, levitated images, and book anaglyphs, are a form of optical illusion. Phantograms use perspectival anamorphosis to produce a 2D image that is distorted in a particular way so as to appear, to a viewer at a particular vantage point, three-dimensional, standing above or recessed into a flat surface. The illusion of depth and perspective is heightened by stereoscopy techniques; a combination of two images, most typically but not necessarily an anaglyph. With common (red–cyan) 3D glasses, the viewer's vision is segregated so that each eye sees a different image.
Margery Edwards (1933–1989) was an Australian Abstract Expressionist artist working in mixed media.
Patrick Hughes is a British artist working in London. He is the creator of "reverspective", an optical illusion on a three-dimensional surface where the parts of the picture which seem farthest away are actually physically the nearest.
Illusionism in art history means either the artistic tradition in which artists create a work of art that appears to share the physical space with the viewer or more broadly the attempt to represent physical appearances precisely – also called mimesis. The term realist may be used in this sense, but that also has rather different meanings in art, as it is also used to cover the choice of ordinary everyday subject-matter, and avoiding idealizing subjects. Illusionism encompasses a long history, from the deceptions of Zeuxis and Parrhasius to the works of muralist Richard Haas in the twentieth century, that includes trompe-l'œil, anamorphosis, optical art, abstract illusionism, and illusionistic ceiling painting techniques such as di sotto in sù and quadratura. Sculptural illusionism includes works, often painted, that appear real from a distance. Other forms, such as the illusionistic tradition in the theatre, and Samuel van Hoogstraten's "peepshow"-boxes from the seventeenth century, combine illusionistic techniques and media.
Monika Sosnowska is a Polish installation artist. In 2003, she received the Bâloise Prize at Art Basel as well as the Polityka's Passport award given by Poland's most prestigious weekly.
John Pugh is an American artist known for creating large trompe-l'œil wall murals giving the illusion of a three-dimensional scene behind the wall. Pugh has been creating his murals since the late 1970s. He attended California State University Chico, receiving his BA in 1983 and the Distinguished Alumni Award in 2003. He has received over 250 public and private commissions in the United States, Canada, Mexico, Barbados, Japan, Taiwan, and New Zealand. He currently lives and works in Ashland, Oregon. His particular style of trompe-l'œil painting has been called "Narrative Illusionism."
Alexa Meade is an American installation artist best known for her portraits painted directly onto the human body and inanimate objects in a way that collapses depth and makes her models appear two-dimensional when photographed. What remains is "a photo of a painting of a person, and the real person hidden somewhere underneath." She takes a classical concept – trompe-l'œil, the art of making a two-dimensional representational painting look like a real three-dimensional space – and does the opposite, making real life appear to be a painting.
Edna Andrade was an American abstract artist. She was an early Op Artist.
Anna Fafaliou (b.1987) is a conceptual artist currently working between London and Los Angeles.
