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Warm Filter
A warm filter is a photographic filter that improves the color of all skin tones and absorbs blue cast often caused by electronic flash or outdoor shade. They add warmth to pale, washed-out flesh tones and are ideal for portraits as they smooth facial details while adding warmth to skin tones (for color imaging). In general, they suppress blue casts on overcast days and on subjects lit by blue sky. See also *Filter factor *Infrared filter *Neutral-density filter *Polarizer *UV filter References {{DEFAULTSORT:Warm Filter Optical filters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Filter
In photography and cinematography, a filter is a camera accessory consisting of an optical filter that can be inserted into the optical path. The filter can be of a square or oblong shape and mounted in a holder accessory, or, more commonly, a glass or plastic disk in a metal or plastic ring frame, which can be screwed into the front of or clipped onto the camera lens. Filters modify the images recorded. Sometimes they are used to make only subtle changes to images; other times the image would simply not be possible without them. In monochrome photography, coloured filters affect the relative brightness of different colours; red lipstick may be rendered as anything from almost white to almost black with different filters. Others change the colour balance of images, so that photographs under incandescent lighting show colours as they are perceived, rather than with a reddish tinge. There are filters that distort the image in a desired way, diffusing an otherwise sharp image, adding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Flash
A flash is a device used in photography that produces a brief burst of light (typically lasting 1/1000 to 1/200 of a second) at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. ''Flash'' refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically. Flash units are commonly built directly into a camera. Some cameras allow separate flash units to be mounted via a standardized accessory mount bracket (a ''hot shoe''). In professional studio equipment, flashes may be large, standalone units, or studio strobes, powered by special battery packs or connected to mains power. They are either synchronized with the camera using a flas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portrait
A portrait is a portrait painting, painting, portrait photography, photograph, sculpture, or other artistic representation of a person, in which the face and its expressions are predominant. The intent is to display the likeness, Personality type, personality, and even the mood of the person. For this reason, in photography a portrait is generally not a Snapshot (photography), snapshot, but a composed image of a person in a still position. A portrait often shows a person looking directly at the painter or photographer, in order to most successfully engage the subject with the viewer. History Prehistorical portraiture Plastered human skulls were reconstructed human skulls that were made in the ancient Levant between 9000 and 6000 BC in the Pre-Pottery Neolithic B period. They represent some of the oldest forms of art in the Middle East and demonstrate that the prehistoric population took great care in burying their ancestors below their homes. The skulls denote some of the earlie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter Factor
In photography Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed ..., filter factor refers to the multiplicative amount of light a filter (photography), filter blocks. Converting between filter factors and stops The table below illustrates the relationship between filter factor, the amount of light that is allowed through the filter, and the number of F-number, stops this corresponds to. Calculating exposure increase The number of f-stops of light reduction, given a filter factor, may be calculated using the formula: \log_(filter factor) Most calculators do not have a \log_ function. An equivalent calculation is: \log_(filter factor) / \log_(2) or \ln(filter factor)/\ln(2) An example: A green filter with a filter factor of 4 \log_(4) = .602 \log_(2)=.301 .602/.301=2 The green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Filter
Infrared cut-off filters, sometimes called IR filters or heat-absorbing filters, are designed to reflect or block near-infrared wavelengths while passing visible light. They are often used in devices with bright incandescent light bulbs (such as slide and overhead projectors) to prevent unwanted heating. There are also filters which are used in solid state ( CCD or CMOS) video cameras to block IR due to the high sensitivity of many camera sensors to near-infrared light. These filters typically have a blue hue to them as they also sometimes block some of the light from the longer red wavelengths. IR transmitting/passing filters in photography In contrast to the naming convention of optical filters where the name of the filter denotes the wavelengths that are blocked, and in line with the convention for air filters and oil filters, photographic filters are named for the color of light they ''pass''. Thus a blue filter makes the picture look blue. A ''blue filter'' marginally allow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutral-density Filter
In photography and optics, a neutral-density filter, or ND filter, is a filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition. It can be a colorless (clear) or grey filter, and is denoted by Wratten number 96. The purpose of a standard photographic neutral-density filter is to reduce the amount of light entering the lens. Doing so allows the photographer to select combinations of aperture, exposure time and sensor sensitivity that would otherwise produce overexposed pictures. This is done to achieve effects such as a shallower depth of field or motion blur of a subject in a wider range of situations and atmospheric conditions. For example, one might wish to photograph a waterfall at a slow shutter speed to create a deliberate motion-blur effect. The photographer might determine that to obtain the desired effect, a shutter speed of ten seconds was needed. On a very bright day, there might be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarizer
A polarizer or polariser is an optical filter that lets light waves of a specific polarization pass through while blocking light waves of other polarizations. It can filter a beam of light of undefined or mixed polarization into a beam of well-defined polarization, that is polarized light. The common types of polarizers are linear polarizers and circular polarizers. Polarizers are used in many optical techniques and instruments, and polarizing filters find applications in photography and LCD technology. Polarizers can also be made for other types of electromagnetic waves besides visible light, such as radio waves, microwaves, and X-rays. Linear polarizers ''Linear polarizers'' can be divided into two general categories: absorptive polarizers, where the unwanted polarization states are absorbed by the device, and beam-splitting polarizers, where the unpolarized beam is split into two beams with opposite polarization states. Polarizers which maintain the same axes of polar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Filter
UV filters are compounds, mixtures, or materials that block or absorb ultraviolet (UV) light. One of the major applications of UV filters is their use as sunscreens to protect skin from sunburn and other sun/UV related damage. After the invention of digital cameras changed the field of photography, UV filters have been used to coat glass discs fitted to camera lenses to protect hardware that is sensitive to UV light. Background Earlier types of photographic film were quite sensitive to UV light, which used to cause haziness or fogginess, and a bluish hue in color film. UV filters were used to filter out shorter ultraviolet wavelengths while remaining transparent to visible light. However, the modern-day photographic film and digital cameras are less sensitive to UV wavelengths. UV filters are sometimes referred to as L37 or L39 filters, depending on the wavelengths of light they filter out. For example, an L37 filter removes ultraviolet light with wavelengths shorter than 370& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
