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Rainbow Classic
A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the Sun. Rainbows can be full circles. However, the observer normally sees only an arc formed by illuminated droplets above the ground, and centered on a line from the Sun to the observer's eye. In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it. In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colours reversed, with red on the inner side of the arc. This is caused by the light being reflected twice on the inside of the drop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary
Secondary may refer to: Science and nature * Secondary emission, of particles ** Secondary electrons, electrons generated as ionization products * The secondary winding, or the electrical or electronic circuit connected to the secondary winding in a transformer * Secondary (chemistry), a term used in organic chemistry to classify various types of compounds * Secondary color, color made from mixing primary colors * Secondary mirror, second mirror element/focusing surface in a reflecting telescope * Secondary craters, often called "secondaries" * Secondary consumer, in ecology * An obsolete name for the Mesozoic in geosciences * Secondary feathers, flight feathers attached to the ulna on the wings of birds Society and culture * Secondary (football), a position in American football and Canadian football * Secondary dominant in music * Secondary education, education which typically takes place after six years of primary education ** Secondary school, the type of school at the secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum. Spectrum has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of condition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarization (waves)
Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string ''(see image)''; for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, and transverse sound waves (shear waves) in solids. An electromagnetic wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glory (optical Phenomenon)
A glory is an optical phenomenon, resembling an iconic saint's halo around the shadow of the observer's head, caused by sunlight or (more rarely) moonlight interacting with the tiny water droplets that comprise mist or clouds. The glory consists of one or more concentric, successively dimmer rings, each of which is red on the outside and bluish towards the centre. Due to its appearance, the phenomenon is sometimes mistaken for a circular rainbow, but the latter has a much larger diameter and is caused by different physical processes. Glories arise due to wave interference of light internally refracted within small droplets. Appearance and observation Depending on circumstances (such as the uniformity of droplet size in the clouds), one or more of the glory's rings can be visible. The angular size of the inner and brightest ring is much smaller than that of a rainbow, about 5° to 20°, depending on the size of the droplets. In the right conditions, a glory and a rainbow can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panorama
A panorama (formed from Greek πᾶν "all" + ὅραμα "view") is any wide-angle view or representation of a physical space, whether in painting, drawing, photography, film, seismic images, or 3D modeling. The word was originally coined in the 18th century by the English (Irish descent) painter Robert Barker to describe his panoramic paintings of Edinburgh and London. The motion-picture term ''panning'' is derived from ''panorama''. A panoramic view is also purposed for multimedia, cross-scale applications to an outline overview (from a distance) along and across repositories. This so-called "cognitive panorama" is a panoramic view over, and a combination of, cognitive spaces used to capture the larger scale. History The device of the panorama existed in painting, particularly in murals, as early as 20 A.D., in those found in Pompeii, as a means of generating an immersive "panoptic" experience of a vista. Cartographic experiments during the Enlightenment era prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Stitching
Image stitching or photo stitching is the process of combining multiple photographic images with overlapping fields of view to produce a segmented panorama or high-resolution image. Commonly performed through the use of computer software, most approaches to image stitching require nearly exact overlaps between images and identical exposures to produce seamless results, although some stitching algorithms actually benefit from differently exposed images by doing high-dynamic-range imaging in regions of overlap. Some digital cameras can stitch their photos internally. Applications Image stitching is widely used in modern applications, such as the following: * Document mosaicing *Image stabilization feature in camcorders that use frame-rate image alignment *High-resolution photomosaics in digital maps and satellite imagery *Medical imaging *Multiple-image super-resolution imaging *Video stitching *Object insertion Process The image stitching process can be divided into three ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Length
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light. A system with a shorter focal length bends the rays more sharply, bringing them to a focus in a shorter distance or diverging them more quickly. For the special case of a thin lens in air, a positive focal length is the distance over which initially collimated (parallel) rays are brought to a focus, or alternatively a negative focal length indicates how far in front of the lens a point source must be located to form a collimated beam. For more general optical systems, the focal length has no intuitive meaning; it is simply the inverse of the system's optical power. In most photography and all telescopy, where the subject is essentially infinitely far away, longer focal length (lower opti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide-angle Lens
In photography and cinematography, a wide-angle lens refers to a lens whose focal length is substantially smaller than the focal length of a normal lens for a given film plane. This type of lens allows more of the scene to be included in the photograph, which is useful in architectural, interior and landscape photography where the photographer may not be able to move farther from the scene to photograph it. Another use is where the photographer wishes to emphasise the difference in size or distance between objects in the foreground and the background; nearby objects appear very large and objects at a moderate distance appear small and far away. This exaggeration of relative size can be used to make foreground objects more prominent and striking, while capturing expansive backgrounds. A wide angle lens is also one that projects a substantially larger image circle than would be typical for a standard design lens of the same focal length. This large image circle enables either lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
135 Film
135 film, more popularly referred to as 35 mm film or 35 mm, is a format of photographic film used for still photography. It is a film with a film gauge of loaded into a standardized type of magazine – also referred to as a cassette or cartridge – for use in 135 film cameras. The engineering standard for this film is controlled by ISO 1007 titled '135-size film and magazine'. The term 135 was introduced by Kodak in 1934 as a designation for 35 mm film specifically for still photography, perforated with Kodak Standard perforations. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film size. Despite competition from formats such as 828, 126, 110, and APS, it remains the most popular film size today. The size of the 135 film frame with its aspect ratio of 1:1.50 has been adopted by many high-end digital single-lens reflex and digital mirrorless cameras, commonly referred to as " full frame". Eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of View
The angle of view is the decisive variable for the visual perception of the size or projection of the size of an object. Angle of view and perception of size The perceived size of an object depends on the size of the image projected onto the retina. The size of the image depends on the angle of vision. A near and a far object can appear the same size if their edges produce the same angle of vision. With an optical device such as glasses or binoculars, microscope and telescope the angle of vision can be widened so that the object appears larger, which is favourable for the resolving power of the eye (see visual angle). Angle of view in photography In photography, angle of view (AOV) describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view. It is important to distinguish the angle of view from the angle of coverage, which describes the angle range that a lens can image. Typically the image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
