|Three Spheres II|
|Artist||M. C. Escher|
|Dimensions||26.9 cm× 46.3 cm(10.6 in× 18.2 in)|
Three Spheres II is a lithograph print by the Dutch artist M. C. Escher first printed in April 1946.
As the title implies, it depicts three spheres resting on a flat surface.
The sphere on the left is transparent with a photorealistic depiction of the refracted light cast through it towards the viewer and onto the flat surface.
The sphere in the center is reflective. Its reflection is a self-replicating image of Escher in his studio drawing the three spheres. In the reflection one can clearly see the image of the three spheres on the paper Escher is drawing on: in the center sphere of that image, one can vaguely make out the reflection of Escher's studio, which is depicted in the main image. This process is implied to be infinite, recursive.
The sphere on the right is opaque and diffuse, i.e. neither specularly reflective nor transparent.
The painting is in the Escher Museum in The Hague.
Electronic paper, also sometimes electronic ink or electrophoretic display, are display devices that mimic the appearance of ordinary ink on paper. Unlike conventional backlit flat panel displays that emit light, electronic paper displays reflect light like paper. This may make them more comfortable to read, and provide a wider viewing angle than most light-emitting displays. The contrast ratio in electronic displays available as of 2008 approaches newspaper, and newly (2008) developed displays are slightly better. An ideal e-paper display can be read in direct sunlight without the image appearing to fade.
Maurits Cornelis Escher was a Dutch graphic artist who made mathematically inspired woodcuts, lithographs, and mezzotints. Despite wide popular interest, Escher was for long somewhat neglected in the art world, even in his native Netherlands. He was 70 before a retrospective exhibition was held. In the twenty-first century, he became more widely appreciated, with exhibitions across the world.
A mirror or reflector is an object such that each narrow beam of light that incides on its surface bounces in a single direction. This property, called specular reflection, distinguishes a mirror from objects that scatter light in many directions, let it pass through them, or absorb it.
In computer graphics, ray tracing is a rendering technique for generating an image by tracing the path of light as pixels in an image plane and simulating the effects of its encounters with virtual objects. The technique is capable of producing a high degree of visual realism, more so than typical scanline rendering methods, but at a greater computational cost. This makes ray tracing best suited for applications where taking a relatively long time to render can be tolerated, such as in still computer-generated images, and film and television visual effects (VFX), but more poorly suited to real-time applications such as video games, where speed is critical in rendering each frame.
A sphere is a geometrical object in three-dimensional space that is the surface of a ball.
A retroreflector is a device or surface that reflects radiation back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, which does this only if the mirror is exactly perpendicular to the wave front, having a zero angle of incidence. Being directed, the retroflector's reflection is brighter than that of a diffuse reflector. Corner reflectors, and Cat’s eye reflectors are the most used kinds.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection.
An optical coating is one or more thin layers of material deposited on an optical component such as a lens or mirror, which alters the way in which the optic reflects and transmits light. One type of optical coating is an antireflection coating, which reduces unwanted reflections from surfaces, and is commonly used on spectacle and photographic lenses. Another type is the high-reflector coating which can be used to produce mirrors which reflect greater than 99.99% of the light which falls on them. More complex optical coatings exhibit high reflection over some range of wavelengths, and anti-reflection over another range, allowing the production of dichroic thin-film optical filters.
Still Life with Spherical Mirror is a lithography print by the Dutch artist M. C. Escher first printed in November 1934. It depicts a setting with rounded bottle and a metal sculpture of a bird with a human face seated atop a newspaper and a book. The background is dark, but in the bottle can be seen the reflection of Escher's studio and Escher himself sketching the scene.
Hand with Reflecting Sphere also known as Self-Portrait in Spherical Mirror is a lithograph by Dutch artist M. C. Escher, first printed in January 1935. The piece depicts a hand holding a reflective sphere. In the reflection, most of the room around Escher can be seen, and the hand holding the sphere is revealed to be Escher's.
Reptiles is a lithograph print by the Dutch artist M. C. Escher first printed in March 1943. It touches on the theme found in much of his work of mathematics in art.
Magic Mirror is a lithograph print by the Dutch artist M. C. Escher first printed in January, 1946.
Puddle is a woodcut print by the Dutch artist M. C. Escher, first printed in February 1952.
Three Worlds is a lithograph print by the Dutch artist M. C. Escher first printed in December 1955.
An antireflective or anti-reflection (AR) coating is a type of optical coating applied to the surface of lenses and other optical elements to reduce reflection. In typical imaging systems, this improves the efficiency since less light is lost due to reflection. In complex systems such as telescopes and microscopes the reduction in reflections also improves the contrast of the image by elimination of stray light. This is especially important in planetary astronomy. In other applications, the primary benefit is the elimination of the reflection itself, such as a coating on eyeglass lenses that makes the eyes of the wearer more visible to others, or a coating to reduce the glint from a covert viewer's binoculars or telescopic sight.
In computer graphics, environment mapping, or reflection mapping, is an efficient image-based lighting technique for approximating the appearance of a reflective surface by means of a precomputed texture image. The texture is used to store the image of the distant environment surrounding the rendered object.
In computer graphics, cube mapping is a method of environment mapping that uses the six faces of a cube as the map shape. The environment is projected onto the sides of a cube and stored as six square textures, or unfolded into six regions of a single texture. The cube map is generated by first rendering the scene six times from a viewpoint, with the views defined by a 90 degree view frustum representing each cube face.
In computer graphics, sphere mapping is a type of reflection mapping that approximates reflective surfaces by considering the environment to be an infinitely far-away spherical wall. This environment is stored as a texture depicting what a mirrored sphere would look like if it were placed into the environment, using an orthographic projection. This texture contains reflective data for the entire environment, except for the spot directly behind the sphere.
Circle Limit III is a woodcut made in 1959 by Dutch artist M. C. Escher, in which "strings of fish shoot up like rockets from infinitely far away" and then "fall back again whence they came".
Dragon is a wood engraving print created by Dutch artist M. C. Escher in April 1952, depicting a folded paper dragon perched on a pile of crystals. It is part of a sequence of images by Escher depicting objects of ambiguous dimension, including also Three Spheres I, Doric Columns, Drawing Hands and Print Gallery.