We have tried to classify those tricks into a different categories:
1. Optical illusion: illusions that are created by light or the mind.
2. Physical illusion: illusions that are created through the manipulation of real objects or materials.
3. Psychological illusion: illusions created through human perception and cognition.
1. Optical illusions are images in which the eye perceives something other than the true form of the image. Visual illusions occur due to optical or physiological factors such as light and shadow, contrast, color and texture. They are often used in visual arts to create an impression of depth.
Illusions are usually classified into categories including the physical and psychological; the physiological classifications include ambiguous images (which present an object that could be interpreted in more than one way), and paradoxical images (which appear to show impossible constructions). The physiological classification can be subdivided into “unusual size”, “distorted size”, “out of proportion” and “impossible object”.
2. Physical illusions signal the brain that there is a problem with what it is seeing. These optical illusions occur because of how the eye observes an object or scene instead of how things truly are. Some physical illusions come from limitations in the neural processing of visual information, others come from how our brains fill in missing information when we don’t have all the data. This latter category provides insights into human perception, and has provided rich ground for psychological research into visual cognition.
3. Psychological illusions are representations of visual or tactile stimuli that can be seen or felt but don’t exist objectively. These types of
Optical illusions are viewed in which the eye sees an object which actually does not exist. The illusion may occur when there is ambiguity in the visual stimulus, or when there is a physical obstruction preventing the eye from seeing a clear image.
The most common optical illusions are based on simple visual perception mechanisms, such as perspective, shadows or color contrast. The sources of optical illusions are often illustrated by experimental psychology and cognitive neuroscience, which show that the perceptual systems of the brain can be easily fooled. In particular, these illusions have been used to argue for a model of vision where human beings construct a mental representation of their environment.
In recent years it has become possible to create images that simulate optical illusions using a computer. An early example is a picture of Abraham Lincoln made in 1922 by overlapping two negatives of his face from different angles. This was done by Scottish artist William Quirk; the result was called Spookliness.
A contemporary example is Pictures of Matchstick Men, developed by Edward H. Adelson at MIT (Massachusetts Institute of Technology), which won the Marr Prize at the 1990 French Connection conference.
Physical illusions are caused by changes in properties of objects or sensory organs producing apparent changes in physical dimensions, while psychological illusions are caused
Anamorphosis is a method of mapping one set of coordinates onto another set of coordinates. It is used in photography and painting, but other means of making anamorphic images also exist, such as volumetric display.
The word “anamorphosis”, coined in the mid-17th century, comes from the Greek words ἀν-, meaning “back” or “again”, and μαρμάρειν, meaning “to change”.
The art of anamorphosis was developed in the later part of the 16th century. It was given its first name much later by Joris Hoefnagel in the year 1568, who named it “Isingskrift”. The artist’s purpose is to trick the human eye, and thus create illusions.
Bertalan Székely wrote a book about this art form in 2002. He called it “The Art of Anamorphoses”, and he introduced three main categories:**
The word “illusion” means “delusion”. So the first thing to say about illusion art is that you should not be deceived by it. It is not an attempt to cheat you.
It is also worth noting that illusion art is not an attempt to deceive people.
In other words, it’s worth remembering that a true artist will always choose beauty over ugliness, rich color over dull shades, and try to make the world a better place with his work.
Visual illusions are technically known as “optical illusions”. We can perceive something which we believe to be real, but in fact is not. The most common of these is called a visual illusion. This can be described as the misinterpretation or misinterpretation of sensory information. This type of illusion is often created by visual images that are perceived incorrectly. There are different types of visual illusions:
The most common types of visual illusions are:
1) Autokinetic effect – when the eye sees an object moving in a strange way, it is usually because the object is being tracked by the eyes and therefore cannot move freely.
2) Phantom Bogey – This optical illusion can be seen when a person is in a very dark place and looks into the distance at a light source such as a street lamp or outside light. The light seems to be moving and appears to have a figure or shape.
3) Spatial disorientation – this effect occurs when two images are placed together on one plane create imaginary movement between them.
4) Scintillating Grid – this effect occurs when there are lines that cross each other at an angle causing them to appear to sparkle or flash with light or shade variations.
5) After Images –
The art of illusion has been around for many centuries, and is practiced by both amateurs and professionals. People who are considered professionals usually have had formal training in the art, and may have even attended a specialized school, such as the Escola Massana in Barcelona, Spain. In some countries illusionists are treated like a profession of illusion.