Forced perspective is a technique which employs optical illusion to make an
object appear farther away, closer, larger or smaller than it actually is.
It is used primarily in photography, filmmaking and architecture. 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. In filmmaking
One example of forced perspective is a scene in an action/adventure movie in
which dinosaurs are threatening the heroes. By placing a miniature model of
a dinosaur close to the camera, the dinosaur may be made to look monstrously
tall to the viewer, even though it is just closer to the camera.
Forced perspective had been a feature of German silent films and Citizen Kane
revived the practice. Movies, especially B-movies in the 1950s and 1960s, were
produced on limited budgets and often featured forced perspective shots.
Forced perspective can be made more believable when environmental conditions
obscure the difference in perspective. For example, the final scene of the
famous movie Casablanca takes place at an airport in the middle of a storm,
although the entire scene was shot in a studio. This was accomplished by using a
painted backdrop of an aircraft, which was "serviced" by dwarfs standing next
to the backdrop. A downpour draws much of the viewer's attention away from the
backdrop and extras, making the simulated perspective less noticeable.
= Role of light= Early instances of forced perspective
used in low-budget motion pictures showed objects that were clearly
different from their surroundings: often blurred or at a different light level.
The principal cause of this was geometric. Light from a point source
travels in a spherical wave, decreasing in intensity as the inverse square of
the distance travelled. This means that a light source must be four times as
bright to produce the same illuminance at an object twice as far away. Thus to
create the illusion of a distant object being at the same distance as a near
object and scaled accordingly, much more light is required. When shooting with
forced perspective, it's important to have the aperture stopped down
sufficiently to achieve proper DOF, so that the foreground object and
background are both sharp. Since miniature models would need to be
subjected to far greater lighting than the main focus of the camera, the area
of action, it is important to ensure that these can withstand the significant
amount of heat generated by the incandescent light sources typically
used in film and TV production. = Nodal point: forced perspective in
motion= Peter Jackson's film adaptations of The
Lord of the Rings make extended use of forced perspective. Characters
apparently standing next to each other would be displaced by several feet in
depth from the camera. This, in a still shot, makes some characters appear much
smaller in relation to others. An extensively used technique in The
Lord of the Rings: The Fellowship of the Ring was an enhancement of this
principle which could be used in moving shots. Portions of sets were mounted on
movable platforms which would move precisely according to the movement of
the camera, so that the optical illusion would be preserved at all times for the
duration of the shot. The same techniques were used in the Harry Potter
movies to make the character Hagrid look like a giant. Props around Harry and his
friends are of normal size, while seemingly identical props placed around
Hagrid are in fact smaller. The techniques developed center around a
nodal point axis, so the camera's panning axis is at the point between the
lens and aperture ring where the light travelling through the camera meets its
axis. By comparison, the normal panning axis would be at the point at which
light would strike the film. The position of this nodal point can be
different for every lens. However, on wide angle lenses it is often found
between the midpoint of the lens and the aperture ring.
= Comic effects= As with many film genres and effects,
forced perspective can be used to visual-comedy effect. Typically, when an
object or character is portrayed in a scene, its size is defined by its
surroundings. A character then interacts with the object or character, in the
process showing that the viewer has been fooled and there is forced perspective
in use. The 1930 Laurel and Hardy movie Brats
used forced perspective to depict Stan and Ollie simultaneously as adults and
as their own sons. An example used for comic effect can be
found in the slapstick comedy Top Secret! in a scene which appears to
begin as a close-up of a ringing phone with the characters in the distance.
However, when the character walks up to the phone and picks it up, it becomes
apparent that the phone is extremely oversized instead of being close to the
camera. Another scene in the same movie begins with a close-up of a wristwatch.
The next cut shows that the character actually has a gargantuan wristwatch.
The same technique is also used in the Dennis Waterman sketch in the British
BBC sketch show Little Britain. In the television version, oversized props are
used to make the caricatured Waterman look just three feet tall or less.
In The History of the World, Part I, while escaping the French peasants, Mel
Brooks' character, Jacques, who is doubling for King Louis, runs down a
hall of the palace, which turns into a ramp, showing the smaller forced
perspective door at the end. As he backs down into the normal part of the room,
he mutters, "Who designed this place?" One of the recurring The Kids in the
Hall sketches featured Mr. Tyzik, "The Headcrusher", who used forced
perspective to "crush" other people's heads between his fingers. This is also
done by the character Sheldon Cooper in the TV show The Big Bang Theory to his
friends when they displease him. In the making of Season 5 of Red vs.
Blue, the creators used forced perspective to make the character of
Tucker's baby look small. In the game, the alien character used as the baby is
the same height as other characters. In architecture
In architecture, a structure can be made to seem larger, taller, farther away or
otherwise by adjusting the scale of objects in relation to the spectator,
increasing or decreasing perceived depth.
For example, when forced perspective is used to make an object appear farther
away, the following method can be used: By constantly decreasing the scale of
objects from expectancy and convention toward the farthest point from the
spectator, an illusion is created that the scale of said objects is decreasing
due to their distant location. In contrast, the opposite technique was
sometimes used in classical garden designs and other "follies" to shorten
the perceived distances of points of interest along a path.
The Statue of Liberty is built with a slight forced perspective so that it
appears more correctly proportioned when viewed from its base. When the statue
was designed in the late 19th century, there were few other angles from which
to view the statue. This caused a difficulty for special effects
technicians working on the movie Ghostbusters II, who had to back off on
the amount of forced perspective used when replicating the statue for the
movie so that their model would not look top-heavy. This effect can also be seen
in Michelangelo's statue of David. Through depth perception
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.
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. 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. = Calculating angular size=
The formula for calculating angular size is as follows:
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.
= 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 father 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 it is known that luminance decreases by ½d,
artists can calculate the exact amount of light needed to counter the cue of
aerial perspective. 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. 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. Another monocular cue of depth
perception is that of lighting and shading. Artists also use lighting to
establish shadows. 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, and therefore, they are apparently much
closer than they are in actuality. A simpler technique employed by artists
is that 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, a
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 has seen 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 are holding. A monocular cue easily taken advantage
of by painters is the trend for the color of objects in the distance to be
shifted more towards the blue end of the spectrum, while closer objects' colors
are shifted toward the red end of the spectrum. A painter can give the
illusion of distance by adding blue or red tinting to the color of the object
he is painting. The optical phenomenon is known as chromostereopsis.
= Examples= In film
Forced perspective has been employed to create dwarfs and giants in film series
such as Hagrid, the half-giant in Harry Potter, and in the special effects of
The Lord of the Rings film series to film the dwarves and hobbits.
In reality, there is only a 5-inch height difference between Elijah Wood,
5′6″, and Ian McKellen, 5′11″, the two actors playing Frodo, and Gandalf,
however the use of camera angles and trick scenery and props creates the
illusion of a much greater difference in size and height.
In art 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 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 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. Theme parks
Forced perspective is extensively employed at theme parks and other such
architecture as found in Disneyland and 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 Disney Theme Parks. Some notable examples of forced perceptive in the
parks, used to make the objects bigger, are the castles. One of the most notable
examples of forced perspective being used to make the object appear smaller
is the The American Adventure Pavilion in EPCOT.
See also Ames room
Anamorphosis Depth perception
Optical illusion Perspective distortion
Trompe-l'œil References