The Vista Paradox refers to an optical illusion that occurs when observing the portico of the Palazzo Bentivoglio from the Cannocchiale di Bologna, which is a long telescope installed on the terrace of the Basilica di San Petronio in Bologna, Italy.
When viewed through the telescope, the portico of the Palazzo Bentivoglio appears to be closer than it actually is. This is because the telescope compresses the depth perception of the scene, making objects appear closer together than they actually are. As a result, the portico, which is actually quite distant from the telescope, appears to be just a few meters away, creating a paradoxical and confusing perception.
The Vista Paradox is an interesting example of how our perception can be easily fooled by optical illusions, and it is a popular attraction for visitors to Bologna who are interested in visual arts and perception.
Table of Contents
- How does the Vista Paradox work?
- Versions of the Vista Paradox
- Illusions like the Vista Paradox
- Discovery of the Vista Paradox
- References and Resources
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How does the Vista Paradox work?
The Vista Paradox is an example of an optical illusion created by the compression of depth perception when viewing a scene through a telescope. When observing the portico of the Palazzo Bentivoglio through the Cannocchiale di Bologna, the telescope compresses the depth of the scene, making objects appear closer together than they actually are.
The illusion works by combining two visual cues that our brain uses to estimate distance: binocular disparity and monocular perspective. Binocular disparity is the slight difference in the position of an object between the two eyes, which allows our brain to calculate depth and distance. Monocular perspective, on the other hand, is the visual cues that are available to one eye alone, such as the size, shape, and texture of objects.
When we look through the telescope, the binocular disparity is eliminated because we are only using one eye to view the scene. This makes it more difficult for the brain to accurately estimate the distance of the objects in the scene. At the same time, the monocular perspective cues are still present, and they give the impression that the portico is much closer than it actually is.
Overall, the combination of these visual cues leads to the Vista Paradox, where the portico appears much closer than it actually is, creating a sense of confusion and perceptual distortion.
Versions of Vista Paradox
The following are a few alternative views of the Vista Paradox at Palazzo Bentivoglio from the Cannocchiale di Bologna.
The first view gives a perspective on distance when the illusion isn’t effecting the perception:
Illusions like The Vista Paradox
The Vista Paradox is a type of visual illusion known as a depth compression illusion. Depth compression illusions occur when our brain misinterprets the relative distances between objects in a scene, causing objects that are far away to appear closer than they actually are.
In the case of the Vista Paradox, the depth compression illusion is created by the use of a telescope, which compresses the depth of the scene and makes the portico of the Palazzo Bentivoglio appear much closer than it actually is. This is due to the elimination of binocular disparity, which is the slight difference in the position of an object between the two eyes, and the reliance on monocular perspective cues, which are the visual cues that are available to one eye alone, such as size, shape, and texture.
Depth compression illusions are just one type of visual illusion that can occur when our brain misinterprets the visual information that it receives. Visual illusions can be caused by a variety of factors, including the properties of light, the organization of visual information, and the cognitive processes that underlie perception.
Some related illusions include the following:
The moon illusions involves the perception of the Moon appearing larger when it is near the horizon compared to when it is high in the sky.
The illusion is an optical illusion and is caused by the way the human brain perceives size and distance.
Factors such as the presence of foreground objects, the size of the Moon in relation to other objects in the sky, and the relative distance of the Moon from the viewer can all contribute to the illusion.
Despite the fact that the Moon’s size does not actually change, it can appear to be much larger when it is near the horizon than when it is high in the sky.
The Müller-Lyer illusion is a classic example of size-contrast illusion, in which two lines of equal length appear to be different due to the presence of arrowheads or fins at the end of the lines.
The Ponzo illusion is a type of visual illusion in which a pair of parallel lines, or a horizontal bar, appear to be of different lengths based on the presence of a converging or diverging set of lines, often resembling the converging parallel lines of a road or railway track, placed above and below them.
The illusion is caused by the way the brain perceives depth and distance, as the converging lines can create the illusion of a receding space, making the upper line appear longer than the lower one, even though they are the same length.
All these illusions demonstrate that the perceived size of an object can be influenced by the context in which it is presented, and that the brain uses the size of the surrounding objects as a reference point to judge the size of the central object.
The Ebbinghaus illusion: This illusion is similar to the Delboeuf illusion but in this case the central circle appears larger when surrounded by smaller circles and smaller when surrounded by larger circles.
The Delboeuf illusion is a perceptual illusion in which the perceived size of a circle is affected by the size of the surrounding circles.
The Occlusion illusion is a visual illusion where an object that is partially obscured by another object appears to be farther away than it actually is. This illusion is caused by the brain’s interpretation of the relative depth of the objects based on their relative size and position. This phenomenon is based on the visual cues that the brain uses to perceive depth, such as relative size, position, and overlap.
The Rubin vase, also known as the Rubin face or the figure-ground vase, is a famous optical illusion in which the image of a vase can also be perceived as two faces in profile looking at each other.
The duck-rabbit illusion is an optical illusion that is an image that can be perceived as either a duck or a rabbit depending on how the viewer looks at it.
The Necker cube is an optical illusion that features a simple wireframe drawing of a cube. The cube appears to switch back and forth between two different orientations.
The My Wife and My Mother-in-Law illusion is an optical illusion with an image of a young woman’s face that can also be perceived as an older woman’s face.
The Schröder Staircase is an optical illusion that features a drawing of a staircase. The staircase appears to be either ascending or descending, depending on how the brain interprets the angles of the lines.
The impossible cube is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.
The Penrose triangle, also known as the Penrose tribar, is an optical illusion that depicts a three-dimensional object that is physically impossible to construct.
Discovery of Vista Paradox
It is not entirely clear who discovered the Vista Paradox, as it is not a well-documented phenomenon in scientific literature. However, it is known that the Vista Paradox has been observed and studied by many scientists, artists, and visitors to Bologna over the years.
One of the earliest known references to the Vista Paradox comes from the Italian artist and scientist Lorenzo Sirigatti, who in the 17th century wrote about the strange and perplexing effect of the Cannocchiale di Bologna in his book “The Art of Painting in Miniature.”
Since then, many other observers have documented and studied the Vista Paradox, including the Italian physicist and mathematician Giovanni Battista Venturi in the 18th century, who wrote about the effect in his book “Memorie di Matematica e di Fisica della Società Italiana delle Scienze,” and the Italian physicist and mathematician Carlo Righini in the 19th century, who published several articles on the subject.
Today, the Vista Paradox continues to be a popular topic of discussion and study for scientists and artists interested in visual perception and optical illusions.
The Cannocchiale di Bologna, also known as the Archiginnasio telescope or the Galilean telescope, was designed by the Italian astronomer Giovanni Battista Hodierna in the 17th century.
Hodierna was born in Ragusa, Sicily in 1597 and was a contemporary of the astronomer Galileo Galilei. He was an active observer of the night sky and published several important astronomical works during his lifetime, including “Istoria e Dimostrazioni intorno alle Macchie Solari” (History and Demonstrations concerning Sunspots) in 1653.
Hodierna designed the Cannocchiale di Bologna to be used for both astronomical and terrestrial observations, and it was installed on the terrace of the Basilica di San Petronio in Bologna, Italy in 1655. The telescope consists of two lenses, one concave and one convex, which magnify distant objects and allow them to be viewed through a long tube.
Today, the Cannocchiale di Bologna is still in use and is a popular attraction for visitors to Bologna who are interested in visual arts and perception.
References and Resources
Check out our complete list of illusions.