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Diffuse Reflection
Diffuse reflection is the reflection of light or other waves or particles from a surface such that a ray incident on the surface is scattered at many angles rather than at just one angle as in the case of specular reflection. An ''ideal'' diffuse reflecting surface is said to exhibit Lambertian reflection, meaning that there is equal luminance when viewed from all directions lying in the half-space adjacent to the surface. A surface built from a non-absorbing powder such as plaster, or from fibers such as paper, or from a polycrystalline material such as white marble, reflects light diffusely with great efficiency. Many common materials exhibit a mixture of specular and diffuse reflection. The visibility of objects, excluding light-emitting ones, is primarily caused by diffuse reflection of light: it is diffusely-scattered light that forms the image of the object in an observer's eye over a wide range of angles of the observer with respect to the object. Mechanism Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambert2
Lambert may refer to People * Lambert (name), a given name and surname * Lambert, Bishop of Ostia (–1130), became Pope Honorius II * Lambert, Margrave of Tuscany (fl. 929–931), also count and duke of Lucca * Lambert (pianist), stage-name of German pianist and composer Paul Lambert *Johann Heinrich Lambert (1728–1777), polymath Places United States * Lambert, Mississippi, a town * Lambert, Missouri, a village *St. Louis Lambert International Airport, St. Louis, Missouri * Lambert, Montana, a rural town in Montana * Lambert, Oklahoma, a town * Lambert Township, Red Lake County, Minnesota * Lambert Castle, a mansion in Paterson, New Jersey * Lambert Creek, San Mateo County, California Elsewhere * Lambert Gravitational Centre, the geographical centre of Australia * Lambert (lunar crater), named after Johann Heinrich Lambert * Lambert (Martian crater), named after Johann Heinrich Lambert Transportation * Lambert (automobile), a defunct American automobile brand * Lambert (cycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amorphous
In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is a characteristic of a crystal. The terms "glass" and "glassy solid" are sometimes used synonymously with amorphous solid; however, these terms refer specifically to amorphous materials that undergo a glass transition. Examples of amorphous solids include glasses, metallic glasses, and certain types of plastics and polymers. Etymology The term "Amorphous" comes from the Greek language, Greek ''a'' ("without"), and ''morphé'' ("shape, form"). Structure Amorphous materials have an internal structure of molecular-scale structural blocks that can be similar to the basic structural units in the crystalline phase of the same compound. Unlike in crystalline materials, however, no long-range regularity exists: amorphous materials cannot be described by the repetition of a finite unit cell. Statistical measures, such as the atomic density ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatic Dispersion
Dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency. Sometimes the term chromatic dispersion is used to refer to optics specifically, as opposed to wave propagation in general. A medium having this common property may be termed a dispersive medium. Although the term is used in the field of optics to describe light and other electromagnetic waves, dispersion in the same sense can apply to any sort of wave motion such as acoustic dispersion in the case of sound and seismic waves, and in gravity waves (ocean waves). Within optics, dispersion is a property of telecommunication signals along transmission lines (such as microwaves in coaxial cable) or the pulses of light in optical fiber. In optics, one important and familiar consequence of dispersion is the change in the angle of refraction of different colors of light, as seen in the spectrum produced by a dispersive prism and in chromatic aberration of lenses. Design of compound achr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Index
In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refraction, refracted, when entering a material. This is described by Snell's law of refraction, , where and are the angle of incidence (optics), angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices and . The refractive indices also determine the amount of light that is reflectivity, reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity (Fresnel equations) and Brewster's angle. The refractive index, n, can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and similarly the wavelength in that me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dielectric Mirror
A dielectric mirror, also known as a Bragg mirror, is a type of mirror composed of multiple thin film, thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material. By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified reflectivity at different wavelengths of light. Dielectric mirrors are also used to produce ultra-high reflectivity mirrors: values of 99.999% or better over a narrow range of wavelengths can be produced using special techniques. Alternatively, they can be made to reflect a broad spectrum of light, such as the entire visible range or the spectrum of the Ti-sapphire laser. Dielectric mirrors are very common in optics experiments, due to improved techniques that allow inexpensive manufacture of high-quality mirrors. Examples of their applications include laser optical cavity, cavity end mirrors, Hot mirror, hot and cold mirrors, thin-film beam splitter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Reflection
In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface. For example, the water-to-air surface in a typical fish tank, when viewed obliquely from below, reflects the underwater scene like a mirror with no loss of brightness (Fig.1). TIR occurs not only with electromagnetic waves such as light and microwaves, but also with other types of waves, including sound and water waves. If the waves are capable of forming a narrow beam (Fig.2), the reflection tends to be described in terms of " rays" rather than waves; in a medium whose properties are independent of direction, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of Incidence (optics)
The angle of incidence, in geometric optics, is the angle between a ray incident on a surface and the line perpendicular (at 90 degree angle) to the surface at the point of incidence, called the normal. The ray can be formed by any waves, such as optical, acoustic, microwave, and X-ray. In the figure below, the line representing a ray makes an angle θ with the normal (dotted line). The angle of incidence at which light is first totally internally reflected is known as the critical angle. The angle of reflection and angle of refraction are other angles related to beams. In computer graphics and geography, the angle of incidence is also known as the illumination angle of a surface with a light source, such as the Earth's surface and the Sun. It can also be equivalently described as the angle between the tangent plane of the surface and another plane at right angles to the light rays. This means that the illumination angle of a certain point on Earth's surface is 0° if the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matte (surface)
Sheen is a measure of the reflected light ( glossiness) from a paint finish. ''Glossy'' and ''flat'' (or ''matte'') are typical extreme levels of glossiness of a finish. Gloss paint is shiny and reflects most light in the specular (mirror-like) direction, while on flat paints most of the light diffuses in a range of angles. The gloss level of paint can also affect its apparent colour. Between those extremes, there are a number of intermediate gloss levels. Their common names, from the most dull to the most shiny, include ''matte'', ''eggshell'', ''satin'', ''silk'', ''semi-gloss'' and ''high gloss''. These terms are not standardized, and not all manufacturers use all these terms. Terminology Firwood, a UK paint manufacturer measures gloss as percentages of light reflected from an emitted source back into an apparatus from specified angles, ranging between 60° and 20° depending on the reflectivity. With very low gloss levels (such as matte finishes), a 60° angle is too grea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paint
Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics. Primitive forms of paint were used tens of thousands of years ago in cave paintings. Clean-up solvents are also different for water-based paint than oil-based paint. Water-based paints and oil-based paints will cure differently based on the outside ambient temperature of the object being painted (such as a house). History Paint was used in some of the earliest known human artworks. Some cave paintings drawn with red or yellow ochre, hematite, manganese oxide, and charcoal may have been made by early ''Homo sapiens'' as long as 40,000 years ago. Paint may be even older. In 2003 and 2004, South African archeologists reported finds in Blombos Cave of a 100,000-y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossy
Gloss is an optical property which indicates how well a surface reflects light in a specular (mirror-like) direction. It is one of the important parameters that are used to describe the visual appearance of an object. Other categories of visual appearance related to the perception of regular or diffuse reflection and transmission of light have been organized under the concept of '' cesia'' in an order system with three variables, including gloss among the involved aspects. The factors that affect gloss are the refractive index of the material, the angle of incident light and the surface texture. Apparent gloss depends on the amount of ''specular'' reflection – light reflected from the surface in an equal amount and the symmetrical angle to the one of incoming light – in comparison with ''diffuse'' reflection – the amount of light scattered into other directions. Theory When light illuminates an object, it interacts with it in a number of ways: * Absorbed within it (large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataract
A cataract is a cloudy area in the lens (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, trouble with bright lights, and Nyctalopia, difficulty seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of Falling (accident), falling and Depression (mood), depression. Cataracts cause 51% of all cases of blindness and 33% of visual impairment worldwide. Cataracts are most commonly due to senescence, aging but may also occur due to Trauma (medicine), trauma or radiation exposure, be congenital cataract, present from birth, or occur following eye surgery for other problems. Risk factors include diabetes mellitus, diabetes, longstanding use of corticosteroid medication, smoking tobacco, prolonged exposu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frost Glass
Frosted glass is produced by the sandblasting or acid etching of clear sheet glass. This creates a pitted surface on one side of the glass pane and has the effect of rendering the glass translucent by scattering the light which passes through, thus blurring images while still transmitting light. It has 10–20% opacity. General applications include: * To achieve visual privacy while still allowing light to pass through. * To create decorative patterns on plain glass by using wax or other inhibitors to retain transparent areas. * To distribute light uniformly in a photographic contact printer. * To create an airtight seal in tubes. * Decorative, aesthetic, or artistic intent. The frosted glass effect can also be achieved by the application of vinyl film, used as a sort of stencil on the glass surface. "Photo-resist", or photo-resistant film is also available, which can be produced to mask off the area surrounding a decorative design, or logo on the glass surface. A simila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
