Aerial perspective, or atmospheric perspective, refers to the effect the
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
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 (for instance, reddish around
sunrise or
sunset
Sunset, also known as sundown, is the daily disappearance of the Sun below the horizon due to Earth's rotation. As viewed from everywhere on Earth (except the North and South poles), the equinox Sun sets due west at the moment of both the spring ...
).
History
Atmospheric perspective was used in Pompeian Second Style frescos, one of the
Pompeian Styles, dating as early as 30 BCE. Notable examples include the Garden Room Fresco from the
Villa of Livia in
Prima Porta, Italy, and the first century Pompeian fresco ''Paris on Mount Ida''.
With varying degrees of accuracy, explanations of the effects of atmospheric perspective were written by
polymaths such as
Leon Battista Alberti and
Leonardo da Vinci. The latter used aerial perspective in many of his paintings such as ''
The Annunciation'', the ''
Mona Lisa'', and ''
The Last Supper'', introducing a technique to paint the effect accurately that was adopted by his followers, the
Leonardeschi. Art historians note that it is lacking in works by some artists of the same period, such as
Raphael, although he adopted the use of
sfumato
Sfumato (, ) is a painting technique for softening the transition between colours, mimicking an area beyond what the human eye is focusing on, or the out-of-focus plane. It is one of the canonical painting modes of the Renaissance. Leonardo da V ...
that was introduced by Leonardo at the same time.
Aerial perspective was used in paintings from the Netherlands in the fifteenth century.
Optics
The major component affecting the appearance of objects during
daylight
Daylight is the combination of all direct and indirect sunlight during the daytime. This includes direct sunlight, diffuse sky radiation, and (often) both of these reflected by Earth and terrestrial objects, like landforms and buildings. Sunligh ...
is
scattering
Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including ...
of light, called
sky light
Daylighting is the practice of placing windows, skylights, other openings, and reflective surfaces so that sunlight (direct or indirect) can provide effective internal lighting. Particular attention is given to daylighting while designing a bui ...
, into the
line of sight of the viewer. Scattering occurs from molecules of the air and also from larger particles in the atmosphere such as water vapour and smoke (see
haze). Scattering adds the sky light as a
veiling luminance onto the light from the object, reducing its contrast with the background sky light. Sky light usually contains more light of short
wavelength than other wavelengths (this is why the sky usually appears blue), which is why distant objects appear bluish (see
Rayleigh scattering for detailed explanation).
Why reducing contrast reduces clarity
The ability of a person with normal
visual acuity to see fine details is determined by
contrast sensitivity. Contrast sensitivity is the
reciprocal of the smallest contrast for which a person can
see a sine-wave
grating. A person's
contrast sensitivity function
Contrast is the contradiction in luminance or colour that makes an object (or its representation in an image or display) distinguishable. In visual perception of the real world, contrast is determined by the difference in the colour and brightn ...
is contrast sensitivity as a function of
spatial frequency. Normally, peak contrast sensitivity is at about four cycles per degree of
visual angle. At higher spatial frequencies, comprising finer and finer lines, contrast sensitivity decreases, until at about forty cycles per degree even the brightest of bright lines and the darkest of dark lines cannot be seen.
The high spatial frequencies in an image give it fine details. Reducing the contrast of an image reduces the visibility of these high spatial frequencies because contrast sensitivity for them already is poor. This is how a reduction of contrast can reduce the clarity of an image—by removing its fine details.
It is important to emphasize that reducing the contrast is not the same as
blurring an image. Blurring is accomplished by reducing the contrast only of the high spatial frequencies. Aerial perspective reduces the contrast of all spatial frequencies.
In art
In art, especially painting, ''aerial perspective, or atmospheric perspective''
'','' refers to the technique of creating an illusion of depth by depicting distant objects as paler, less detailed, and usually bluer than near objects. This technique was introduced in painting by Leonardo da Vinci to portray what was observed in nature and evident in his interest in optics.
The technique allows a painter to capture the effect that
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
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 colour of the
atmosphere
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
, which is bluish when sunlit, but will shift to other colours under certain conditions (for instance, reddish around
sunrise and
sunset
Sunset, also known as sundown, is the daily disappearance of the Sun below the horizon due to Earth's rotation. As viewed from everywhere on Earth (except the North and South poles), the equinox Sun sets due west at the moment of both the spring ...
or
saturated during
fog
Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influ ...
).
(One caution: in common speech, the words ''perspective'' and ''viewpoint'' tend to be used interchangeably; however, in art, aerial perspective does not imply an
aerial viewpoint
A bird's-eye view is an elevated view of an object or location from a very steep viewing angle, creating a perspective as if the observer were a bird in flight looking downwards. Bird's-eye views can be an aerial photograph, but also a draw ...
, such as that forming the basis of the
aerial landscape genre. The example by
Frans Koppelaar
Frans Thomas Koppelaar (born April 23, 1943), is a Dutch painter, who was born in The Hague, Netherlands.
From 1963 to 1969, he attended the Royal Academy of Visual Arts at The Hague. He moved to Amsterdam in 1968.
His landscapes and Amsterd ...
pictured here shows the difference. This landscape is a good example of aerial perspective; however, it is not an aerial landscape, since apparently, the observer is standing on the ground.) As such, the term atmospheric perspective can be understood to better describe how properties of the scene's atmosphere effect the appearance of an object as it moves further from the viewer.
See also
*
Aerial landscape art
*
Aerial shot
Aerial may refer to:
Music
* ''Aerial'' (album), by Kate Bush
* ''Aerials'' (song), from the album ''Toxicity'' by System of a Down
Bands
*Aerial (Canadian band)
* Aerial (Scottish band)
* Aerial (Swedish band)
Performance art
* Aerial sil ...
*
Haze
*
Landscape art
*
List of art techniques
A ''list'' is any set of items in a row. List or lists may also refer to:
People
* List (surname)
Organizations
* List College, an undergraduate division of the Jewish Theological Seminary of America
* SC Germania List, German rugby union ...
*
Rayleigh scattering
*
Teide
*
Tyndall effect
References
{{reflist
Perspective projection
Artistic techniques
Vision
Perception
Visual perception
Composition in visual art