Early in December, thousands of students, faculty, and visitors gather around the front campus fountain for an annual Christmas carol sing and lighting ceremony, culminating in the illumination of tens of thousands of Christmas lights.

Diatomaceous earth as viewed under Bright field microscopy | bright field lighting | illumination on a light microscope.

Global illumination is a general name for a group of algorithms used in 3D computer graphics that are meant to add more realistic lighting to 3D scenes.

Radiosity, ray tracing, beam tracing, cone tracing, path tracing, Metropolis light transport, ambient occlusion, photon mapping, and image based lighting are examples of algorithms used in global illumination, some of which may be used together to yield results that are not fast, but accurate.

These algorithms model diffuse inter-reflection which is a very important part of global illumination ; however most of these ( excluding radiosity ) also model specular reflection, which makes them more accurate algorithms to solve the lighting equation and provide a more realistically illuminated scene.

In real-time 3D graphics, the diffuse inter-reflection component of global illumination is sometimes approximated by an " ambient " term in the lighting equation, which is also called " ambient lighting " or " ambient color " in 3D software packages.

Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination.

The invention and development of the high-power white-light LED led to use for illumination, which is fast replacing incandescent and fluorescent lighting

This method of sample illumination gives rise to extremely even lighting and overcomes many limitations of older techniques of sample illumination.

The lamps represent the illumination of the 7 stars, and lighting them are believed to absolve sins while prolonging one's lifespan.

Terbium " green " phosphors ( which fluoresce a brilliant lemon-yellow ) are combined with divalent europium blue phosphors and trivalent europium red phosphors to provide " trichromatic " lighting technology, a high-efficiency white light used for standard illumination in indoor lighting.

For example, a domestic ubiquitous computing environment might interconnect lighting and environmental controls with personal biometric monitors woven into clothing so that illumination and heating conditions in a room might be modulated, continuously and imperceptibly.

Brown exists as a color perception only in the presence of a brighter color contrast yellow, orange, red, or rose objects are still perceived as such if the general illumination level is low, despite reflecting the same amount of red or orange light as a brown object would in normal lighting conditions.

In photography and theatrical lighting, the inverse-square law is used to determine the " fall off " or the difference in illumination on a subject as it moves closer to or further from the light source.

Before the invention of electric lighting, candles and oil lamps were commonly used for illumination.

The intensity of a luminaire ( lighting instrument or fixture ) depends on a number of factors including its lamp power, the design of the instrument ( and its efficiency ), optical obstructions such as color gels or mechanical filters, the distance to the area to be lit and the beam or field angle of the fixture, the color and material to be lit, and the relative contrasts to other regions of illumination.

Diatomaceous earth as viewed under bright field microscopy | bright field lighting | illumination on a light microscope.

There is also often an ambient light value that is added to all final lighting calculations to arbitrarily compensate for global illumination effects which rasterization can not calculate correctly.

Passive solar lighting techniques enhance taking advantage of natural illumination for interiors, and so reduce reliance on artificial lighting systems.

The reflector had found favor where the choices of artificial light provided poor illumination compared to modern electric lighting.

This method of sample illumination gives rise to extremely even lighting and overcomes many limitations of older techniques of sample illumination.

In 1893 August Köhler developed a key technique for sample illumination, Köhler illumination, which is central to modern light microscopy.

Phase contrast microscopy is an optical microscopy illumination technique in which small phase shifts in the light passing through a transparent specimen are converted into amplitude or contrast changes in the image.

* Phase contrast microscopy, an optical microscopy illumination technique

" He also used a realist technique which French novelist Marcel Proust later named " retrospective illumination ", whereby a character's past is revealed long after she or he first appears.

Computer display systems use a technique called chromatic adaptation transforms to emulate the correlated color temperature of illumination sources, and cannot perfectly reproduce the intricate spectral combinations originally seen.

* For soft indirect illumination, if the surface is Lambertian, then a technique known as irradiance caching may be used to interpolate values from previous calculations.

* Differential interference contrast microscopy, an illumination technique in optical microscopy

In principle, the technique can be used at any range and on any target provided that illumination can be controlled.

The successive diminution of letters following an initial had also been seen, again notably in the Cathach, and would also be a standard technique in Insular illumination.

Most often, processes are studied after the illumination of a material occurs, but in principle, the technique can be applied to any process that leads to a change in properties of a material.

The former method is attenuated phase-shifting, and is often considered a weak enhancement, requiring special illumination for the most enhancement, while the latter method is known as alternating-aperture phase-shifting, and is the most popular strong enhancement technique.

It is used for Precomputed Radiance Transfer-a technique similar to spherical harmonics lighting that is used for precomputed global illumination and soft ambient lighting.

Two filters are normally used in this technique ; an illumination ( or excitation ) filter which ensures the illumination is near monochromatic and at the correct wavelength, and a second emission ( or barrier ) filter which ensures none of the excitation light source reaches the detector.

Confocal microscopy is an optical imaging technique used to increase optical resolution and contrast of a micrograph by using point illumination and a spatial pinhole to eliminate out-of-focus light in specimens that are thicker than the focal plane.

The " structured illumination " technique of superresolution is related to Moire patterns.

This technique of Ground-controlled interception ( GCI ) was preceded by the use of single-engined non radar-equipped BF 109s guided to the attacking bombers by the illumination of searchlights, termed ; Helle Nachtjagd-illuminated night fighting.

The visual effect of this blurring technique is a smooth blur resembling that of viewing the image through a translucent screen, distinctly different from the bokeh effect produced by an out-of-focus lens or the shadow of an object under usual illumination.

However, in order to delay as long as possible the vast expense and difficulty of adopting a whole new type of illumination technology, manufacturers have turned to a technique, previously used in microscopes, for increasing the numerical aperture of the lens by allowing the light to pass through water instead of air.

DIC has largely replaced the older oblique illumination ( OI ) technique, which was available on reflected light microscopes prior to about 1975.

In computer graphics, per-pixel lighting refers to any technique for lighting an image or scene that calculates illumination for each pixel on a rendered image.