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Light Tent
A light tent is a box used for taking photos of objects without casting shadows. It can, for example, be used to take pictures of a physical product for use in an encyclopedia, for documentation or for marketing. The combination of evenly distributed lighting and the diffusing material means that minimal shadows are cast, and it can appear as if the pictured product is "floating in nothing", and a neutral image without a disturbing background can be achieved. Glossy or reflective objects in particular can require a light tent in order to avoid unwanted reflections in the picture. Walls and materials The walls in the box is made of a diffusing material such that light spreads well when it hits the surface. White is the most commonly used color, but other colors can also be used. This contributes to uniform lighting of the object. For example, one can use matte white paper sheets, but felt or another types of matte textile can also function as a background and substrate. Size L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DIY Lightbox
"Do it yourself" ("DIY") is the method of building, wikt:modification, modifying, or repairing things by oneself without the direct aid of professionals or certified experts. Academic research has described DIY as behaviors where "individuals use Raw material, raw and semi-raw materials and parts to produce, transform, or reconstruct material possessions, including those drawn from the natural environment (e.g., landscaping)". DIY behavior can be triggered by various motivations previously categorized as market economy, marketplace motivations (economic benefits, lack of product availability, lack of product quality, need for customization), and identity (social science), identity enhancement (Workmanship, craftsmanship, empowerment, community seeking, uniqueness). The term "do-it-yourself" has been associated with consumers since at least 1912 primarily in the domain of home improvement and maintenance activities. The phrase "do it yourself" had come into common usage (in st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-point Lighting
Three-point lighting is a standard method used in visual media such as theatre, video, film, Portrait photography, still photography, computer-generated imagery and 3D computer graphics. By using three separate positions, the photographer can illuminate the shot's subject (such as a person) however desired, while also controlling (or eliminating entirely) the shading and shadows produced by direct lighting. The ''key light'', as the name suggests, shines directly upon the subject and serves as its principal illuminator; more than anything else, the strength, color and angle of the key determines the shot's overall lighting design. In indoor shots, the key is commonly a specialized lamp, or a camera's flash. In outdoor daytime shots, the Sun often serves as the key light. In this case, of course, the photographer cannot set the light in the exact position they want, so instead arranges the shot to best capture the sunlight, perhaps after waiting for the sun to position itself just ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightbox
A lightbox is a translucent surface illuminated from behind, used for situations where a shape laid upon the surface needs to be seen with high contrast. Types Several varieties exist, depending on their purpose: * Various backlit viewing devices: ** A container with several lightbulbs and a pane of frosted glass on the top. It is used by photography professionals viewing transparent films, such as slides. This device was originally used to sort photographic plates with ease. When laid flat, it may be called a light table. Generally, a lightbox uses light similar to daylight (5,000–6,000 kelvins (K)) and has uniform light strength on the glass pane. **In the form of vertical panels, they can also be found mounted on the walls of hospitals and medical offices to review X-ray images (X-ray illuminator). ** In the science field, lightboxes are often used for looking at bacterial growth and allow better visualization for PCR plates. ** A lighted display panel used for adve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Balance
In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly neutral colors like white or grey – correctly. Hence, the general method is sometimes called gray balance, neutral balance, or white balance. Color balance changes the overall mixture of colors in an image and is used for color correction. Generalized versions of color balance are used to correct colors other than neutrals or to deliberately change them for effect. White balance is one of the most common kinds of balancing, and is when colors are adjusted to make a white object (such as a piece of paper or a wall) appear white and not a shade of any other colour. Image data acquired by sensors – either film or electronic image sensors – must be transformed from the acquired values to new values that are appropriate for color reproduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Speed
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to describe the relationship between exposure and output image lightness in digital cameras. Relatively insensitive film, with a correspondingly lower speed index, requires more exposure to light to produce the same image density as a more sensitive film, and is thus commonly termed a ''slow film''. Highly sensitive films are correspondingly termed ''fast films''. In both digital and film photography, the reduction of exposure corresponding to use of higher sensitivities generally leads to reduced image quality (via coarser film grain or higher image noise of other types). In short, the higher the sensitivity, the grainier the image will be. Ultimately sensitivity is limited by the quantum efficiency of the film or sensor. Film speed measurement systems His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depth Of Field
The depth of field (DOF) is the distance between the nearest and the furthest objects that are in acceptably sharp focus in an image captured with a camera. Factors affecting depth of field For cameras that can only focus on one object distance at a time, depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus. "Acceptably sharp focus" is defined using a property called the "circle of confusion". The depth of field can be determined by focal length, distance to subject, the acceptable circle of confusion size, and aperture. Limitations of depth of field can sometimes be overcome with various techniques and equipment. The approximate depth of field can be given by: : \text \approx \frac for a given circle of confusion (c), focal length (f), f-number (N), and distance to subject (u). As distance or the size of the acceptable circle of confusion increases, the depth of field increases; however, increasing the size of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An optical system typically has many openings or structures that limit the ray bundles (ray bundles are also known as ''pencils'' of light). These structures may be the edge of a lens or mirror, or a ring or other fixture that holds an optical element in place, or may be a special element such as a diaphragm placed in the optical path to limit the light admitted by the system. In general, these structures are called stops, and the aperture stop is the stop that primarily determines the ray cone angle and brightness at the image point. In some contexts, especially in photography and astronomy, ''aperture'' refers to the diameter of the aperture stop rather than the physical stop or the opening itself. For example, in a telescope, the aperture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-number
In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill Professional, p. 183. It is also known as the focal ratio, f-ratio, or f-stop, and is very important in photography. It is a dimensionless number that is a quantitative measure of lens speed; increasing the f-number is referred to as ''stopping down''. The f-number is commonly indicated using a lower-case hooked f with the format ''N'', where ''N'' is the f-number. The f-number is the reciprocal of the relative aperture (the aperture diameter divided by focal length). Notation The f-number is given by: N = \frac \ where f is the focal length, and D is the diameter of the entrance pupil (''effective aperture''). It is customary to write f-numbers preceded by "", which forms a mathematical expression of the entrance pupil diameter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). The Kelvin scale is an absolute thermodynamic temperature scale, meaning it uses absolute zero as its null (zero) point. Historically, the Kelvin scale was developed by shifting the starting point of the much-older Celsius scale down from the melting point of water to absolute zero, and its increments still closely approximate the historic definition of a degree Celsius, but since 2019 the scale has been defined by fixing the Boltzmann constant to be exactly . Hence, one kelvin is equal to a change in the thermodynamic temperature that results in a change of thermal energy by . The temperature in degree Celsius is now defined as the temperature in kelvins minus 273.15, meaning t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Temperature
Color temperature is the color of light emitted by an idealized opaque, non-reflective body at a particular temperature measured in kelvins. The color temperature scale is used to categorize the color of light emitted by other light sources regardless of their temperature. Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, horticulture, and other fields. In practice, color temperature is meaningful only for light sources that do in fact correspond somewhat closely to the color of some black body, i.e., light in a range going from red to orange to yellow to white to bluish white; it does not make sense to speak of the color temperature of, e.g., a green or a purple light. Color temperature is conventionally expressed in kelvins, using the symbol K, a unit of measure for absolute temperature. Color temperatures over 5000 K are called "cool colors" (bluish) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera
A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a small hole (the aperture) that allows light to pass through in order to capture an image on a light-sensitive surface (usually a Image sensor, digital sensor or photographic film). Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera, and the aperture can be narrowed or widened. A Shutter (photography), shutter mechanism determines the amount of time the photosensitive surface is exposed to the light. The still image camera is the main instrument in the art of photography. Captured images may be reproduced later as part of the process of photography, digital imaging, or photographic printing. Similar artistic fields in the moving-image camera dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photograph
A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now created using a smartphone/camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of what the human eye would see. The process and practice of creating such images is called photography. Etymology The word ''photograph'' was coined in 1839 by Sir John Herschel and is based on the Greek φῶς (''phos''), meaning "light," and γραφή (''graphê''), meaning "drawing, writing," together meaning "drawing with light." History The first permanent photograph, a contact-exposed copy of an engraving, was made in 1822 using the bitumen-based "heliography" process developed by Nicéphore Niépce. The first photographs of a real-world scene, made using a camera obscura, followed a few years later at Le Gras, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
