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Fixed Focus Lens
A photographic lens for which the focus is not adjustable is called a fixed-focus lens or sometimes focus-free. The focus is set at the time of lens design, and remains fixed. It is usually set to the hyperfocal distance, so that the depth of field ranges all the way down from half that distance to infinity, which is acceptable for most cameras used for capturing images of humans or objects larger than a meter. Rather than having a method of determining the correct focusing distance and setting the lens to that focal point, a fixed-focus lens relies on sufficient depth of field to produce acceptably sharp images. Most cameras with focus-free lenses also have a relatively small aperture, which increases the depth of field. Fixed-focus cameras with extended depth of field (EDOF) sometimes are known as full-focus cameras. Concept In order to reach a minimal focal distance, the aperture and the focal length of the lens are reduced (a slow wide-angle lens), to make the hyperfocal d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back Of IPhone 3G White Showing The Fixed Focus 2 Megapixel Camera
The human back, also called the dorsum (: dorsa), is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck. It is the surface of the body opposite from the chest and the abdomen. The vertebral column runs the length of the back and creates a central area of recession. The breadth of the back is created by the shoulders at the top and the pelvis at the bottom. Back pain is a common medical condition, generally benign in origin. Structure The central feature of the human back is the vertebral column, specifically the length from the top of the thoracic vertebrae to the bottom of the lumbar vertebrae, which houses the spinal cord in its spinal canal, and which generally has some curvature that gives shape to the back. The ribcage extends from the spine at the top of the back (with the top of the ribcage corresponding to the T1 vertebra), more than halfway down the length of the back, leaving an area with less protection between th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disposable Camera
A disposable or single-use camera is a simple box camera meant to be used once. Most use fixed-focus lenses. Some are equipped with an integrated flash unit, and there are even waterproof versions for underwater photography. Internally, the cameras use a 135 film or an APS cartridge. While some disposables contain an actual cartridge as used for loading normal, reusable cameras, others just have the film wound internally on an open spool. The whole camera is handed in for processing. Some of the cameras are recycled, i.e. refilled with film and resold. The cameras are returned for "processing" in the same fashion as film cameras. In general the one-time-use camera represents a return to the business model pioneered by Kodak for their Kodak camera, predecessor to the Brownie camera; it is particularly popular in situations where a reusable camera would be easily stolen or damaged, when one's regular camera is forgotten, or if one cannot afford a regular camera. History A c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autofocus
An autofocus (AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication. Autofocus methods are distinguished as active, passive or hybrid types. Autofocus systems rely on one or more sensors to determine correct focus. Some AF systems rely on a single sensor, while others use an array of sensors. Most modern SLR cameras use through-the-lens optical sensors, with a separate sensor array providing light metering, although the latter can be programmed to prioritize its metering to the same area as one or more of the AF sensors. Through-the-lens optical autofocusing is usually speedier and more precise than manual focus with an ordinary viewfinder, although more precise manual focus can be achieved with special accessories such as focusing magnifiers. Autofocus accur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-field Camera
A light field camera, also known as a plenoptic camera, is a camera that captures information about the ''light field'' emanating from a scene; that is, the intensity of light in a scene, and also the precise direction that the light rays are traveling in space. This contrasts with conventional cameras, which record only light intensity at various wavelengths. One type uses an array of micro-lenses placed in front of an otherwise conventional image sensor to sense intensity, color, and directional information. Multi-camera arrays are another type. A holographic image is a type of film-based light field image. History Early research The first light field camera was proposed by Gabriel Lippmann in 1908. He called his concept " integral photography". Lippmann's experimental results included crude integral photographs made by using a plastic sheet embossed with a regular array of microlenses, or by partially embedding small glass beads, closely packed in a random pattern, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Photography
Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other flight, airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAVs or "drones"), balloon (aircraft), balloons, blimps and dirigibles, rockets, pigeon photography, pigeons, kite aerial photography, kites, or using action cameras while skydiving or wingsuiting. Handheld cameras may be manually operated by the photographer, while mounted cameras are usually remote operation, remotely operated or triggered automatically. Aerial photography typically refers specifically to bird's-eye view images that focus on landscapes and Earth surface, surface objects, and should not be confused with air-to-air photography, where one or more aircraft are used as chase planes that "chase" and photograph other aircraft in flight. Elevated photography can also produce b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circle Of Confusion
In optics, a circle of confusion (CoC) is an optical spot caused by a cone of light ray (optics), rays from a lens (optics), lens not coming to a perfect focus (optics), focus when imaging a Point source#Light, point source. It is also known as disk of confusion, circle of indistinctness, blur circle, or blur spot. In photography, the circle of confusion is used to determine the depth of field, the part of an image that is acceptably sharp. A standard value of CoC is often associated with each film format, image format, but the most appropriate value depends on visual acuity, viewing conditions, and the amount of enlargement. Usages in context include ''maximum permissible circle of confusion'', ''circle of confusion diameter limit'', and the ''circle of confusion criterion''. Real lenses defocus, do not focus all rays perfectly, so that even at best focus, a point is imaged as a spot rather than a point. The smallest such spot that a lens can produce is often referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Sensor
An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) into signal (electrical engineering), signals, small bursts of electric current, current that convey the information. The waves can be light or other electromagnetic radiation. Image sensors are used in electronics, electronic imaging devices of both analogue electronics, analog and digital electronics, digital types, which include digital cameras, camera modules, camera phones, optical mouse devices, medical imaging equipment, night vision equipment such as thermography, thermal imaging devices, radar, sonar, and others. As technological change, technology changes, electronic and digital imaging tends to replace chemical and analog imaging. The two main types of electronic image sensors are the charge-coupled device (CCD) and the active-pixel s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera Phone
A camera phone is a mobile phone that is able to capture photographs and often record video using one or more built-in digital cameras. It can also send the resulting image wirelessly and conveniently. The first commercial phone with a color camera was the Kyocera Visual Phone VP-210, released in Japan in May 1999. While cameras in mobile phones used to be supplementary, they have been a major selling point of mobile phones since the 2010s. Most camera phones are smaller and simpler than the separate digital cameras. In the smartphone era, the steady sales increase of camera phones caused point-and-shoot camera sales to peak about 2010, and decline thereafter. The concurrent improvement of smartphone camera technology and its other multifunctional benefits have led to it gradually replacing compact point-and-shoot cameras. Most modern smartphones only have a menu choice to start a camera application program and an on-screen button to activate the shutter. Some also have a sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveillance Cameras
Closed-circuit television (CCTV), also known as video surveillance, is the use of closed-circuit television cameras to transmit a signal to a specific place on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point, point-to-multipoint (P2MP), or mesh wired or wireless links. Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring (videotelephony is seldom called "CCTV"). The deployment of this technology has facilitated significant growth in state surveillance, a substantial rise in the methods of advanced social monitoring and control, and a host of crime prevention measures throughout the world. Though surveillance of the public using CCTV is common in many areas around the world, video surveillance has generated significant debate about balancing its use wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Webcam
A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in Videotelephony, video telephony, live streaming and social media, and Closed-circuit television, security. Webcams can be Built-in function, built-in computer hardware or Peripheral, peripheral devices, and are commonly connected to a device using USB or Internet protocol suite, wireless protocol. Webcams have been used on the Internet as early as 1993, and the first widespread commercial one became available in 1994. Early webcam usage on the Internet was primarily limited to stationary shots streamed to web sites. In the late 1990s and early 2000s, instant messaging clients added support for webcams, increasing their popularity in video conferencing. Computer manufacturers later started integrating webcams into laptop hardware. In 2020, the COVID-19 pandemic caused a shortage of webcams due to the increased number of people Remote work, working from hom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCD Camera
A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging. Overview In a CCD image sensor, pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors. These MOS capacitors, the basic building blocks of a CCD, are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface; the CCD is then used to read out these charges. Although CCDs are not the only technology to allow for light detection, CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viewfinder
In photography, a viewfinder is a device on a camera that a photographer uses to determine exactly where the camera is pointed, and approximately how much of that view will be photographed. A viewfinder can be mechanical (indicating only direction and approximate view), with simple optical components, with precision optics and optical functions, or a digital accessory device used with digital cameras. View camera, View camera These cameras had no separate viewfinder. The exact image (although upside-down and reversed left-right) was viewed on a ground glass installed either in a replaceable plateholder, or in a spring back where springs hold the ground glass at the focus plane until a photographic plateholder is slid in front of it. Spring backs usually had a flip-up cover protecting the ground glass. A black focusing cloth was used with larger models. Mechanical finders Later referred to as "sports finders", for many sports and newspaper applications optical viewfinders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
