Editing Forced perspective (section)

==Through depth perception==
[[File:Potěmkinovy schody.jpg|thumb|right|The [[Potemkin Stairs]] in [[Odesa]] extend for {{convert|142|m|ft}}, but give the illusion of greater depth since the stairs are wider at the bottom than at the top.]]
The technique takes advantage of the visual cues humans use to perceive depth such as angular size, aerial perspective, shading, and relative size. In film, photography and art, perceived object distance is manipulated by altering fundamental [[monocular cues]] used to discern the depth of an object in the scene such as aerial perspective, blurring, relative size and lighting.<ref>{{Cite book|url=https://www.sagepub.com/sites/default/files/upm-binaries/66081_Schwartz_Chapter_7.pdf|title=Depth and Size Perception|publisher=SAGE|year=2015|pages=169–179}}</ref> Using these monocular cues in concert with [[angular size]], the eyes can perceive the distance of an object. Artists are able to freely move the visual plane of objects by obscuring these cues to their advantage.

Increasing the object's distance from the audience makes an object appear smaller, its apparent size decreases as distance from the audience increases. This phenomenon is that of the manipulation of angular and apparent size. The [[Ames room]] attraction in some museums and amusement parks takes advantage of distance to make people appear different sizes in corners of a room that appears rectangular to the viewer.

A person perceives the size of an object based on the size of the object's image on the retina. This depends solely on the angle created by the rays coming from the topmost and bottommost part of the object that pass through the center of the lens of the eye. The larger the angle an object subtends, the larger the apparent size of the object. The subtended angle increases as the object moves closer to the lens. Two objects with different actual size have the same apparent size when they subtend the same angle. Similarly, two objects of the same actual size can have drastically varying apparent size when they are moved to different distances from the lens.<ref>Knight, Randall Dewey., Brian Jones, and Stuart Field. College Physics: a Strategic Approach. 1st ed. San Francisco: Pearson Education, 2006. Print. p. 704-705.</ref>

===Calculating angular size===
[[File:Angular Size.jpg|thumb|alt=Angular Size depiction.|Angular size, distance and object size]]
The formula for calculating angular size is as follows:
:<math>\theta=2\cdot\arctan\frac{h}{2D}</math>

in which ''θ'' is the subtended angle, ''h'' is the actual size of the object and ''D'' is the distance from the lens to the object.<ref>Michael A. Seeds; Dana E. Backman (2010). Stars and Galaxies (7 ed.). Brooks Cole. p. 39.</ref>

===Techniques employed===
* Solely manipulating angular size by moving objects closer and farther away cannot fully trick the eye. Objects that are farther away from the eye have a lower luminescent contrast due to atmospheric scattering of rays. Fewer rays of light reach the eye from more distant objects. Using the monocular cue of aerial perspective, the eye uses the relative luminescence of objects in a scene to discern relative distance. Filmmakers and photographers combat this cue by manually increasing the luminescence of objects farther away to equal that of objects in the desired plane. This effect is achieved by making the more distant object more bright by shining more light on it. Because luminance decreases by ½''d'' (where ''d'' is distance from the eye), artists can calculate the exact amount of light needed to counter the cue of aerial perspective.<ref>O'Shea, R.P., Blackburn, S.G., & Ono, H. (1994). Contrast as a depth cue. Vision Research, 34, 1595–1604.</ref>
* Similarly, blurring can create the opposite effect by giving the impression of depth. Selectively blurring an object moves it out of its original visual plane without having to manually move the object.<ref>George Mather (1996) "Image Blur as a Pictorial Depth Cue". Proceedings: Biological Sciences, Vol. 263, No. 1367 (Feb. 22, 1996), pp. 169–172.</ref>
* A perceptive illusion that may be infused in film culture is the idea of Gestalt psychology, which holds that people often view the whole of an object as opposed to the sum of its individual parts.<ref>{{cite web|title = Gestalt Psychology|url=http://webspace.ship.edu/cgboer/gestalt.html|access-date=5 March 2013}}</ref>
* Another monocular cue of depth perception is that of lighting and shading. Shading in a scene or on an object allows the audience to locate the light source relative to the object. Making two objects at different distances have the same shading gives the impression that they are in similar positions relative to the light source; therefore, they appear closer to each other than they actually are.<ref>Lipton, L. (1982) Foundations of the Stereoscopic Cinema - A Study in Depth. New York, Van Nostrand Reinhold, pg 56.</ref>
* Artists may also employ the simpler technique of manipulating relative size. Once the audience becomes acquainted with the size of an object in proportion to the rest of the objects in a scene, the photographer or filmmaker can replace the object with a larger or smaller replica to change another part of the scene's apparent size. This is done frequently in movies. For example, to aid in the appearance of a person as a giant next to a "regular sized" person, a filmmaker might have a shot of two identical glasses together, then follow with the person who is supposed to play the giant holding a much smaller replica of the glass and the person who is playing the regular-sized person holding a much larger replica. Because the audience sees that the glasses are the same size in the original shot, the difference in relation to the two characters allows the audience to perceive the characters as different sizes based on their relative size to the glasses they hold.<ref name="Purves">Purves D, Lotto B (2003) ''Why We See What We Do: An Empirical Theory of Vision''. Sunderland, MA: Sinauer Associates.</ref>
* A painter can give the illusion of distance by adding blue or red tinting to the color of the object he is painting. This monocular cue takes advantage of the trend for the color of distant objects to shift towards the blue end of the spectrum, while the colors of closer objects shift toward the red end of the spectrum.<ref name="Purves"/> The optical phenomenon is known as [[chromostereopsis]].

=== Examples ===

====In film====
Forced perspective has been employed to realize characters in film. One notable example is [[Rubeus Hagrid]], the half-giant in the ''[[Harry Potter (film series)|Harry Potter]]'' series.{{citation needed|date=October 2021}}

The technique is used in the ''[[special effects of The Lord of the Rings film series|Lord of the Rings]]'' series for depicting the apparent heights of the [[hobbit]] characters, such as Frodo, who are supposed to be around half the height or less of the humans and wizards, such as Gandalf. In reality, the difference in height between the respective actors playing those roles is only {{convert|5|in|cm}}, where [[Elijah Wood]] as the hobbit Frodo is {{height|ft=5|in=6}} tall, and [[Ian McKellen]] as the wizard Gandalf is {{height|ft=5|in=11}}. The use of camera angles and trick scenery and props creates the illusion of a much greater difference in size and height.{{citation needed|date=October 2021}}

Numerous camera angle tricks are played in the comedy film [[Elf (film)|''Elf'']] (2003) to make the elf characters in the movie appear smaller than the human characters.<ref>{{Cite web|url=http://www.mirror.co.uk/3am/celebrity-news/11-things-you-might-not-6812057|title=24 Elf the movie facts including why Will Ferrell refuses to do a sequel|last=Rowney|first=Jo-Anne|date=2018-12-03|website=mirror|access-date=2020-04-23}}</ref>

====In art====
[[File:Cézanne, Paul - Still Life with a Curtain.jpg|thumb|right|''Still life with a curtain'']]
In his painting entitled ''Still life with a curtain'', [[Paul Cézanne]] creates the illusion of depth by using brighter colors on objects closer to the viewer and dimmer colors and shading to distance the "light source" from objects that he wanted to appear farther away. His shading technique allows the audience to discern the distance between objects due to their relative distances from a stationary light source that illuminates the scene. Furthermore, he uses a blue tint on objects that should be farther away and redder tint to objects in the foreground.

====Full size dioramas====
[[Image:DSC01677 Diorama isole Lofoten - Museo di storia naturale, Milano - Foto di G. Dall'Orto - 20-12-2006.jpg|thumbnail|A diorama in the Museum of Natural History in [[Milan]] ([[Italy]])]]

Modern museum [[dioramas]] may be seen in most major natural history museums. Typically, these displays use a tilted plane to represent what would otherwise be a level surface, incorporate a painted background of distant objects, and often employ false perspective, carefully modifying the scale of objects placed on the plane to reinforce the [[illusion]] through [[depth perception]] in which objects of identical real-world size placed farther from the observer appear smaller than those closer. Often the distant painted background or sky will be painted upon a continuous curved surface so that the viewer is not distracted by corners, seams, or edges. All of these techniques are means of presenting a realistic view of a large scene in a compact space. A photograph or single-eye view of such a diorama can be especially convincing since in this case there is no distraction by the [[binocular disparity|binocular perception]] of depth.

[[Carl Akeley]], a naturalist, sculptor, and taxidermist, is credited with creating the first ever habitat diorama in the year 1889. Akeley's diorama featured taxidermied beavers in a three-dimensional habitat with a realistic, painted background. With the support of curator [[Frank M. Chapman]], Akeley designed the popular habitat dioramas featured at the [[American Museum of Natural History]]. Combining art with science, these exhibitions were intended to educate the public about the growing need for [[habitat conservation]]. The modern [[AMNH Exhibitions Lab]] is charged with the creation of all dioramas and otherwise immersive environments in the museum.<ref>Stephen Christopher Quinn, Windows on Nature: The Great Habitat Dioramas of the American Museum of Natural History, Abrams, New York, 2006.</ref>

====[[Theme parks]]====
Forced perspective is extensively employed at theme parks and other such architecture as found in [[Disneyland Park (Anaheim)|Disneyland]] and [[Las Vegas, Nevada|Las Vegas]], often to make structures seem larger than they are in reality where physically larger structures would not be feasible or desirable, or to otherwise provide an [[optical illusion]] for entertainment value. Most notably, it is used by [[Walt Disney Imagineering]] in the [[Walt Disney Parks and Resorts|Disney Theme Parks]]. Some notable examples of forced perspective in the parks, used to make the objects bigger, are the castles ([[Sleeping Beauty Castle|Sleeping Beauty]], [[Cinderella's Castle|Cinderella]], [[Le Château de la Belle au Bois Dormant|Belle]], [[Castle of Magical Dreams|Magical Dreams]], and [[Enchanted Storybook Castle|Enchanted Storybook]]).<ref>{{Cite web|url=http://duchessofdisneyland.com/tips-trivia/forced-perspective/|title=Forced Perspective|date=2014-06-05|website=Duchess of Disneyland|language=en-US|access-date=2020-04-23}}</ref> One of the most notable examples of forced perspective being used to make the object appear smaller is [[The American Adventure (Epcot)|The American Adventure]] pavilion in Epcot.

<gallery>
File:Sleeping Beauty Castle Main-Street.JPG|At [[Sleeping Beauty Castle]] in [[Disneyland Park (Anaheim)|Disneyland]], the scale of architectural elements is much smaller in the upper reaches of the castle compared to the foundation, making it seem significantly taller than its actual height of {{convert|77|ft|m|abbr=off|sp=us}}.
File:Cinderella Castle 2013 Wade.jpg|At [[Cinderella Castle]] in [[Walt Disney World]]'s [[Magic Kingdom]], the scale once again gets smaller the higher one goes, making it seem significantly taller than its actual height of {{convert|189|ft|m|abbr=off|sp=us}}.
File:Epcotusa.jpg|[[The American Adventure (Epcot)|The American Adventure]] pavilion in [[Epcot]], also in Walt Disney World, uses forced perspective to make a five-story building appear to be two and a half stories.<ref name="American Adventure">{{cite book|last1=Wright]|first1=the Imagineers ; [Alex|title=The Imagineering Field Guide to Epcot at Walt Disney World : an Imagineer's-Eye Tour.|date=2007|publisher=Disney Editions|location=New York|isbn=978-0786848867|page=103|edition=1st}}<!--|access-date=5 October 2014--></ref>
</gallery>