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 pass through or reflect off objects) into signals , small bursts of current that convey the information. The waves can be light or other electromagnetic radiation . Image sensors are used in electronic imaging devices of both analog and digital types, which include digital cameras , camera modules , camera phones , optical mouse devices, medical imaging equipment, night vision equipment such as thermal imaging devices, radar , sonar , and others. As technology changes , electronic and digital imaging tends to replace chemical and analog imaging.
80-419: A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor , or chemically via a light-sensitive material such as photographic film . As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of
160-485: A 5 μm NMOS integrated circuit sensor chip. Since the first commercial optical mouse, the IntelliMouse introduced in 1999, most optical mouse devices use CMOS sensors. In February 2018, researchers at Dartmouth College announced a new image sensing technology that the researchers call QIS, for Quanta Image Sensor. Instead of pixels, QIS chips have what the researchers call "jots." Each jot can detect
240-402: A 12% decrease since 2019. The new sensor contains 200 million pixels in a 1-by-1.4-inch (25 by 36 mm) lens. The charge-coupled device (CCD) was invented by Willard S. Boyle and George E. Smith at Bell Labs in 1969. While researching MOS technology, they realized that an electric charge was the analogy of the magnetic bubble and that it could be stored on a tiny MOS capacitor . As it
320-452: A 120 roll, and twice that number of a 220 film. These correspond to 6x9, 6x7, 6x6, and 6x4.5 respectively (all dimensions in cm). Notable manufacturers of large format and roll film SLR cameras include Bronica , Graflex , Hasselblad , Seagull , Mamiya and Pentax . However, the most common format of SLR cameras has been 35 mm and subsequently the migration to digital SLR cameras, using almost identical sized bodies and sometimes using
400-467: A built-in light meter or exposure meter. Taken through the lens (called TTL metering ), these readings are taken using a panel of light-sensitive semiconductors . They are used to calculate optimal exposure settings. These settings are typically determined automatically as the reading is used by the camera's microprocessor . The reading from the light meter is incorporated with aperture settings, exposure times, and film or sensor sensitivity to calculate
480-415: A certain range, providing the convenience of adjusting the scene capture without moving the camera or changing the lens. A prime lens, in contrast, has a fixed focal length. While less flexible, prime lenses often provide superior image quality, are typically lighter, and perform better in low light. Focus involves adjusting the lens elements to sharpen the image of the subject at various distances. The focus
560-449: A commonplace activity. The century also marked the rise of computational photography , using algorithms and AI to enhance image quality. Features like low-light and HDR photography , optical image stabilization, and depth-sensing became common in smartphone cameras. Most cameras capture light from the visible spectrum , while specialized cameras capture other portions of the electromagnetic spectrum , such as infrared . All cameras use
640-520: A critical role as it determines how much of the scene the camera can capture and how large the objects appear. Wide-angle lenses provide a broad view of the scene, while telephoto lenses capture a narrower view but magnify the objects. The focal length also influences the ease of taking clear pictures handheld, with longer lengths making it more challenging to avoid blur from small camera movements. Two primary types of lenses include zoom and prime lenses. A zoom lens allows for changing its focal length within
720-426: A curved sensor in 2014 to reduce/eliminate Petzval field curvature that occurs with a flat sensor. Use of a curved sensor allows a shorter and smaller diameter of the lens with reduced elements and components with greater aperture and reduced light fall-off at the edge of the photo. Early analog sensors for visible light were video camera tubes . They date back to the 1930s, and several types were developed up until
800-572: A hybrid CCD/CMOS architecture (sold under the name " sCMOS ") consists of CMOS readout integrated circuits (ROICs) that are bump bonded to a CCD imaging substrate – a technology that was developed for infrared staring arrays and has been adapted to silicon-based detector technology. Another approach is to utilize the very fine dimensions available in modern CMOS technology to implement a CCD like structure entirely in CMOS technology: such structures can be achieved by separating individual poly-silicon gates by
880-445: A lens mounted on a lens board which was separated from the plate by extendible bellows. There were simple box cameras for glass plates but also single-lens reflex cameras with interchangeable lenses and even for color photography ( Autochrome Lumière ). Many of these cameras had controls to raise, lower, and tilt the lens forwards or backward to control perspective. Image sensor The two main types of electronic image sensors are
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#1732798030193960-400: A magnifier loupe, view finder, angle finder, and focusing rail/truck. Some professional SLRs can be provided with interchangeable finders for eye-level or waist-level focusing, focusing screens , eyecup, data backs, motor-drives for film transportation or external battery packs. In photography, the single-lens reflex camera (SLR) is provided with a mirror to redirect light from the lens to
1040-400: A measure of how much light is recorded during the exposure. There is a direct relationship between the exposure times and aperture settings so that if the exposure time is lengthened one step, but the aperture opening is also narrowed one step, then the amount of light that contacts the film or sensor is the same. In most modern cameras, the amount of light entering the camera is measured using
1120-404: A mechanical or electronic shutter, the latter of which is common in smartphone cameras. Electronic shutters either record data from the entire sensor simultaneously (a global shutter) or record the data line by line across the sensor (a rolling shutter). In movie cameras, a rotary shutter opens and closes in sync with the advancement of each frame of film. The duration for which the shutter is open
1200-529: A photodiode array without external memory . However, in 1914 Deputy Consul General Carl R. Loop, reported to the state department in a Consular Report on Archibald M. Low's Televista system that "It is stated that the selenium in the transmitting screen may be replaced by any diamagnetic material ". In June 2022, Samsung Electronics announced that it had created a 200 million pixel image sensor. The 200MP ISOCELL HP3 has 0.56 micrometer pixels with Samsung reporting that previous sensors had 0.64 micrometer pixels,
1280-407: A short burst of bright light during exposure and is a commonly used artificial light source in photography. Most modern flash systems use a battery-powered high-voltage discharge through a gas-filled tube to generate bright light for a very short time (1/1,000 of a second or less). Many flash units measure the light reflected from the flash to help determine the appropriate duration of the flash. When
1360-817: A single particle of light, called a photon . Computational photography Computational photography refers to digital image capture and processing techniques that use digital computation instead of optical processes. Computational photography can improve the capabilities of a camera, or introduce features that were not possible at all with film-based photography, or reduce the cost or size of camera elements. Examples of computational photography include in-camera computation of digital panoramas , high-dynamic-range images , and light field cameras . Light field cameras use novel optical elements to capture three dimensional scene information which can then be used to produce 3D images, enhanced depth-of-field , and selective de-focusing (or "post focus"). Enhanced depth-of-field reduces
1440-427: A small display, offering a wider range of information such as live exposure previews and histograms, albeit at the cost of potential lag and higher battery consumption. Specialized viewfinder systems exist for specific applications, like subminiature cameras for spying or underwater photography . Parallax error , resulting from misalignment between the viewfinder and lens axes, can cause inaccurate representations of
1520-405: A specialized trade in the 1850s, designs and sizes were standardized. The latter half of the century witnessed the advent of dry plates and roll-film , prompting a shift towards smaller and more cost-effective cameras, epitomized by the original Kodak camera, first produced in 1888. This period also saw significant advancements in lens technology and the emergence of color photography, leading to
1600-560: A surge in camera ownership. The first half of the 20th century saw continued miniaturization and the integration of new manufacturing materials. After World War I, Germany took the lead in camera development, spearheading industry consolidation and producing precision-made cameras. The industry saw significant product launches such as the Leica camera and the Contax , which were enabled by advancements in film and lens designs. Additionally, there
1680-420: A very small gap; though still a product of research hybrid sensors can potentially harness the benefits of both CCD and CMOS imagers. There are many parameters that can be used to evaluate the performance of an image sensor, including dynamic range , signal-to-noise ratio , and low-light sensitivity. For sensors of comparable types, the signal-to-noise ratio and dynamic range improve as the size increases. It
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#17327980301931760-482: A well-conditioned problem. The coded aperture can also improve the quality in light field acquisition using Hadamard transform optics. Coded aperture patterns can also be designed using color filters, in order to apply different codes at different wavelengths. This allows to increase the amount of light that reaches the camera sensor, compared to binary masks. Computational imaging is a set of imaging techniques that combine data acquisition and data processing to create
1840-409: Is a currently popular buzzword in computer graphics, many of its techniques first appeared in the computer vision literature, either under other names or within papers aimed at 3D shape analysis. Computational photography, as an art form, has been practiced by capture of differently exposed pictures of the same subject matter, and combining them together. This was the inspiration for the development of
1920-446: Is a major concern. Both types of sensor accomplish the same task of capturing light and converting it into electrical signals. Each cell of a CCD image sensor is an analog device. When light strikes the chip it is held as a small electrical charge in each photo sensor . The charges in the line of pixels nearest to the (one or more) output amplifiers are amplified and output, then each line of pixels shifts its charges one line closer to
2000-589: Is a sub-field of computational photography. Photos taken using computational photography can allow amateurs to produce photographs rivalling the quality of professional photographers, but as of 2019 do not outperform the use of professional-level equipment. This is controlling photographic illumination in a structured fashion, then processing the captured images, to create new images. The applications include image-based relighting, image enhancement, image deblurring , geometry/material recovery and so forth. High-dynamic-range imaging uses differently exposed pictures of
2080-474: Is adjusted through the focus ring on the lens, which moves the lens elements closer or further from the sensor. Autofocus is a feature included in many lenses, which uses a motor within the lens to adjust the focus quickly and precisely based on the lens's detection of contrast or phase differences. This feature can be enabled or disabled using switches on the lens body. Advanced lenses may include mechanical image stabilization systems that move lens elements or
2160-411: Is adjusted, the opening expands and contracts in increments called f-stops . The smaller the f-stop, the more light is allowed to enter the lens, increasing the exposure. Typically, f-stops range from f / 1.4 to f / 32 in standard increments: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, and 32. The light entering the camera is halved with each increasing increment. The wider opening at lower f-stops narrows
2240-459: Is an assembly of multiple optical elements, typically made from high-quality glass. Its primary function is to focus light onto a camera's film or digital sensor, thereby producing an image. This process significantly influences image quality, the overall appearance of the photo, and which parts of the scene are brought into focus. A camera lens is constructed from a series of lens elements, small pieces of glass arranged to form an image accurately on
2320-400: Is applied in imaging, and deconvolution is performed to recover the image. In coded exposure imaging , the on/off state of the shutter is coded to modify the kernel of motion blur . In this way motion deblurring becomes a well-conditioned problem . Similarly, in a lens based coded aperture, the aperture can be modified by inserting a broadband mask . Thus, out of focus deblurring becomes
2400-428: Is because in a given integration (exposure) time, more photons hit the pixel with larger area. Exposure time of image sensors is generally controlled by either a conventional mechanical shutter , as in film cameras, or by an electronic shutter . Electronic shuttering can be "global," in which case the entire image sensor area's accumulation of photoelectrons starts and stops simultaneously, or "rolling" in which case
2480-408: Is called the shutter speed or exposure time . Typical exposure times can range from one second to 1/1,000 of a second, though longer and shorter durations are not uncommon. In the early stages of photography, exposures were often several minutes long. These long exposure times often resulted in blurry images, as a single object is recorded in multiple places across a single image for the duration of
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2560-432: Is correctly placed. The photographer then winds the film, either manually or automatically depending on the camera, to position a blank portion of the film in the path of the light. Each time a photo is taken, the film advance mechanism moves the exposed film out of the way, bringing a new, unexposed section of film into position for the next shot. The film must be advanced after each shot to prevent double exposure — where
2640-461: Is dictated by the sensor's size and properties, necessitating storage media such as Compact Flash , Memory Sticks , and SD (Secure Digital) cards . Modern digital cameras typically feature a built-in monitor for immediate image review and adjustments. Digital images are also more readily handled and manipulated by computers, offering a significant advantage in terms of flexibility and post-processing potential over traditional film. A flash provides
2720-463: Is pulled across the film plane during exposure. The focal-plane shutter is typically used in single-lens reflex (SLR) cameras, since covering the film (rather than blocking the light passing through the lens) allows the photographer to view the image through the lens at all times, except during the exposure itself. Covering the film also facilitates removing the lens from a loaded camera, as many SLRs have interchangeable lenses. A digital camera may use
2800-578: The Canon Pellix and others with a small periscope such as in the Corfield Periflex series. The large-format camera, taking sheet film, is a direct successor of the early plate cameras and remained in use for high-quality photography and technical, architectural, and industrial photography. There are three common types: the view camera, with its monorail and field camera variants, and the press camera . They have extensible bellows with
2880-436: The active-pixel sensor ( CMOS sensor). The passive-pixel sensor (PPS) was the precursor to the active-pixel sensor (APS). A PPS consists of passive pixels which are read out without amplification , with each pixel consisting of a photodiode and a MOSFET switch. It is a type of photodiode array , with pixels containing a p-n junction , integrated capacitor , and MOSFETs as selection transistors . A photodiode array
2960-474: The charge-coupled device (CCD) and the active-pixel sensor ( CMOS sensor). Both CCD and CMOS sensors are based on metal–oxide–semiconductor (MOS) technology, with CCDs based on MOS capacitors and CMOS sensors based on MOSFET (MOS field-effect transistor) amplifiers . Analog sensors for invisible radiation tend to involve vacuum tubes of various kinds, while digital sensors include flat-panel detectors . The two main types of digital image sensors are
3040-739: The charge-coupled device (CCD) and the active-pixel sensor (CMOS sensor), fabricated in complementary MOS (CMOS) or N-type MOS ( NMOS or Live MOS ) technologies. Both CCD and CMOS sensors are based on the MOS technology , with MOS capacitors being the building blocks of a CCD, and MOSFET amplifiers being the building blocks of a CMOS sensor. Cameras integrated in small consumer products generally use CMOS sensors, which are usually cheaper and have lower power consumption in battery powered devices than CCDs. CCD sensors are used for high end broadcast quality video cameras, and CMOS sensors dominate in still photography and consumer goods where overall cost
3120-462: The pinned photodiode (PPD). It was invented by Nobukazu Teranishi , Hiromitsu Shiraki and Yasuo Ishihara at NEC in 1980. It was a photodetector structure with low lag, low noise , high quantum efficiency and low dark current . In 1987, the PPD began to be incorporated into most CCD devices, becoming a fixture in consumer electronic video cameras and then digital still cameras . Since then,
3200-431: The wearable computer in the 1970s and early 1980s. Computational photography was inspired by the work of Charles Wyckoff , and thus computational photography datasets (e.g. differently exposed pictures of the same subject matter that are taken in order to make a single composite image) are sometimes referred to as Wyckoff Sets, in his honor. Early work in this area (joint estimation of image projection and exposure value)
3280-492: The 1980s. By the early 1990s, they had been replaced by modern solid-state CCD image sensors. The basis for modern solid-state image sensors is MOS technology, which originates from the invention of the MOSFET by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959. Later research on MOS technology led to the development of solid-state semiconductor image sensors, including the charge-coupled device (CCD) and later
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3360-547: The PPD has been used in nearly all CCD sensors and then CMOS sensors. The NMOS active-pixel sensor (APS) was invented by Olympus in Japan during the mid-1980s. This was enabled by advances in MOS semiconductor device fabrication , with MOSFET scaling reaching smaller micron and then sub-micron levels. The first NMOS APS was fabricated by Tsutomu Nakamura's team at Olympus in 1985. The CMOS active-pixel sensor (CMOS sensor)
3440-670: The United States by 2003. In contrast, the film camera industry in the UK, Western Europe, and the USA declined during this period, while manufacturing continued in the USSR, German Democratic Republic, and China, often mimicking Western designs. The 21st century witnessed the mass adoption of digital cameras and significant improvements in sensor technology. A major revolution came with the incorporation of cameras into smartphones, making photography
3520-438: The amplifiers, filling the empty line closest to the amplifiers. This process is then repeated until all the lines of pixels have had their charge amplified and output. A CMOS image sensor has an amplifier for each pixel compared to the few amplifiers of a CCD. This results in less area for the capture of photons than a CCD, but this problem has been overcome by using microlenses in front of each photodiode, which focus light into
3600-455: The angular spectrum of the object is being reconstructed. Other techniques are related to the field of computational imaging, such as digital holography , computer vision and inverse problems such as tomography . This is processing of non-optically-coded images to produce new images. These are detectors that combine sensing and processing, typically in hardware, like the oversampled binary image sensor . Although computational photography
3680-413: The camera dates back to the 19th century and has since evolved with advancements in technology, leading to a vast array of types and models in the 21st century. Cameras function through a combination of multiple mechanical components and principles. These include exposure control, which regulates the amount of light reaching the sensor or film; the lens, which focuses the light; the viewfinder, which allows
3760-404: The camera through an aperture, an opening adjusted by overlapping plates called the aperture ring. Typically located in the lens, this opening can be widened or narrowed to alter the amount of light that strikes the film or sensor. The size of the aperture can be set manually, by rotating the lens or adjusting a dial or automatically based on readings from an internal light meter. As the aperture
3840-532: The composition, lighting, and exposure of their shots, enhancing the accuracy of the final image. Viewfinders fall into two primary categories: optical and electronic. Optical viewfinders, commonly found in Single-Lens Reflex (SLR) cameras, use a system of mirrors or prisms to reflect light from the lens to the viewfinder, providing a clear, real-time view of the scene. Electronic viewfinders, typical in mirrorless cameras, project an electronic image onto
3920-419: The degree of magnification expected of the final image. The shutter, along with the aperture, is one of two ways to control the amount of light entering the camera. The shutter determines the duration that the light-sensitive surface is exposed to light. The shutter opens, light enters the camera and exposes the film or sensor to light, and then the shutter closes. There are two types of mechanical shutters:
4000-528: The evolution of the technology in the 19th century was driven by pioneers like Thomas Wedgwood , Nicéphore Niépce , and Henry Fox Talbot . First using the camera obscura for chemical experiments, they ultimately created cameras specifically for chemical photography, and later reduced the camera's size and optimized lens configurations. The introduction of the daguerreotype process in 1839 facilitated commercial camera manufacturing, with various producers contributing diverse designs. As camera manufacturing became
4080-449: The exposure interval of each row immediate precedes that row's readout, in a process that "rolls" across the image frame (typically from top to bottom in landscape format). Global electronic shuttering is less common, as it requires "storage" circuits to hold charge from the end of the exposure interval until the readout process gets there, typically a few milliseconds later. There are several main types of color image sensors, differing by
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#17327980301934160-415: The exposure. To prevent this, shorter exposure times can be used. Very short exposure times can capture fast-moving action and eliminate motion blur. However, shorter exposure times require more light to produce a properly exposed image, so shortening the exposure time is not always possible. Like aperture settings, exposure times increment in powers of two. The two settings determine the exposure value (EV),
4240-540: The finger pressure was released. The Asahiflex II , released by Japanese company Asahi (Pentax) in 1954, was the world's first SLR camera with an instant return mirror. In the single-lens reflex camera, the photographer sees the scene through the camera lens. This avoids the problem of parallax which occurs when the viewfinder or viewing lens is separated from the taking lens. Single-lens reflex cameras have been made in several formats including sheet film 5x7" and 4x5", roll film 220/120 taking 8,10, 12, or 16 photographs on
4320-554: The flash is attached directly to the camera—typically in a slot at the top of the camera (the flash shoe or hot shoe) or through a cable—activating the shutter on the camera triggers the flash, and the camera's internal light meter can help determine the duration of the flash. Additional flash equipment can include a light diffuser , mount and stand, reflector, soft box , trigger and cord. Accessories for cameras are mainly used for care, protection, special effects, and functions. Large format cameras use special equipment that includes
4400-408: The image of an object through indirect means to yield enhanced resolution , additional information such as optical phase or 3D reconstruction . The information is often recorded without using a conventional optical microscope configuration or with limited datasets. Computational imaging allows to go beyond physical limitations of optical systems, such as numerical aperture , or even obliterates
4480-436: The image sensor itself to counteract camera shake, especially beneficial in low-light conditions or at slow shutter speeds. Lens hoods, filters, and caps are accessories used alongside a lens to enhance image quality, protect the lens, or achieve specific effects. The camera's viewfinder provides a real-time approximation of what will be captured by the sensor or film. It assists photographers in aligning, focusing, and adjusting
4560-498: The introduction of the affordable Ricohflex III TLR in 1952 to the first 35mm SLR with automatic exposure, the Olympus AutoEye in 1960, new designs and features continuously emerged. Electronics became integral to camera design in the 1970s, evident in models like Polaroid's SX-70 and Canon's AE-1 . Transition to digital photography marked the late 20th century, culminating in digital camera sales surpassing film cameras in
4640-426: The late 20th and early 21st century, use electronic sensors to capture and store images. The rapid development of smartphone camera technology in the 21st century has blurred the lines between dedicated cameras and multifunctional devices, profoundly influencing how society creates, shares, and consumes visual content. Beginning with the use of the camera obscura and transitioning to complex photographic cameras,
4720-465: The leaf-type shutter and the focal-plane shutter. The leaf-type uses a circular iris diaphragm maintained under spring tension inside or just behind the lens that rapidly opens and closes when the shutter is released. More commonly, a focal-plane shutter is used. This shutter operates close to the film plane and employs metal plates or cloth curtains with an opening that passes across the light-sensitive surface. The curtains or plates have an opening that
4800-590: The lens and shutter mounted on a lens plate at the front. Backs taking roll film and later digital backs are available in addition to the standard dark slide back. These cameras have a wide range of movements allowing very close control of focus and perspective. Composition and focusing are done on view cameras by viewing a ground-glass screen which is replaced by the film to make the exposure; they are suitable for static subjects only and are slow to use. The earliest cameras produced in significant numbers were plate cameras , using sensitized glass plates. Light entered
4880-436: The light-sensitive surface. Each element is designed to reduce optical aberrations , or distortions, such as chromatic aberration (a failure of the lens to focus all colors at the same point), vignetting (darkening of image corners), and distortion (bending or warping of the image). The degree of these distortions can vary depending on the subject of the photo. The focal length of the lens, measured in millimeters, plays
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#17327980301934960-544: The need for optical elements . For parts of the optical spectrum where imaging elements such as objectives are difficult to manufacture or image sensors cannot be miniaturized, computational imaging provides useful alternatives, in fields such as X-ray and THz radiations . Among common computational imaging techniques are lensless imaging , computational speckle imaging, ptychography and Fourier ptychography . Computational imaging technique often draws on compressive sensing or phase retrieval techniques, where
5040-501: The need for mechanical focusing systems. All of these features use computational imaging techniques. The definition of computational photography has evolved to cover a number of subject areas in computer graphics , computer vision , and applied optics . These areas are given below, organized according to a taxonomy proposed by Shree K. Nayar . Within each area is a list of techniques, and for each technique one or two representative papers or books are cited. Deliberately omitted from
5120-424: The optimal exposure. Light meters typically average the light in a scene to 18% middle gray. More advanced cameras are more nuanced in their metering—weighing the center of the frame more heavily (center-weighted metering), considering the differences in light across the image (matrix metering), or allowing the photographer to take a light reading at a specific point within the image (spot metering). A camera lens
5200-417: The photodiode that would have otherwise hit the amplifier and not been detected. Some CMOS imaging sensors also use Back-side illumination to increase the number of photons that hit the photodiode. CMOS sensors can potentially be implemented with fewer components, use less power, and/or provide faster readout than CCD sensors. They are also less vulnerable to static electricity discharges. Another design,
5280-406: The range of focus so the background is blurry while the foreground is in focus. This depth of field increases as the aperture closes. A narrow aperture results in a high depth of field, meaning that objects at many different distances from the camera will appear to be in focus. What is acceptably in focus is determined by the circle of confusion , the photographic technique, the equipment in use and
5360-403: The same basic design: light enters an enclosed box through a converging or convex lens and an image is recorded on a light-sensitive medium. A shutter mechanism controls the length of time that light enters the camera. Most cameras also have a viewfinder, which shows the scene to be recorded, along with means to adjust various combinations of focus , aperture and shutter speed . Light enters
5440-429: The same lens systems. Almost all SLR cameras use a front-surfaced mirror in the optical path to direct the light from the lens via a viewing screen and pentaprism to the eyepiece. At the time of exposure, the mirror is flipped up out of the light path before the shutter opens. Some early cameras experimented with other methods of providing through-the-lens viewing, including the use of a semi-transparent pellicle as in
5520-414: The same scene to extend dynamic range. Other examples include processing and merging differently illuminated images of the same subject matter ("lightspace"). This is capture of optically coded images, followed by computational decoding to produce new images. Coded aperture imaging was mainly applied in astronomy or X-ray imaging to boost the image quality. Instead of a single pin-hole, a pinhole pattern
5600-871: The same section of film is exposed to light twice, resulting in overlapped images. Once all frames on the film roll have been exposed, the film is rewound back into the cartridge, ready to be removed from the camera for developing. In digital cameras, sensors typically comprise Charge-Coupled Devices (CCDs) or Complementary Metal-Oxide-Semiconductor (CMOS) chips, both of which convert incoming light into electrical charges to form digital images. CCD sensors, though power-intensive, are recognized for their excellent light sensitivity and image quality. Conversely, CMOS sensors offer individual pixel readouts, leading to less power consumption and faster frame rates, with their image quality having improved significantly over time. Digital cameras convert light into electronic data that can be directly processed and stored. The volume of data generated
5680-403: The shutter is briefly opened to allow light to pass during the exposure. Loading film into a film camera is a manual process. The film, typically housed in a cartridge, is loaded into a designated slot in the camera. One end of the film strip, the film leader, is manually threaded onto a take-up spool. Once the back of the camera is closed, the film advance lever or knob is used to ensure the film
5760-400: The subject's position. While negligible with distant subjects, this error becomes prominent with closer ones. Some viewfinders incorporate parallax-compensating devices to mitigate that issue. Image capture in a camera occurs when light strikes a light-sensitive surface: photographic film or a digital sensor . Housed within the camera body, the film or sensor records the light's pattern when
5840-607: The taxonomy are image processing (see also digital image processing ) techniques applied to traditionally captured images in order to produce better images. Examples of such techniques are image scaling , dynamic range compression (i.e. tone mapping ), color management , image completion (a.k.a. inpainting or hole filling), image compression , digital watermarking , and artistic image effects. Also omitted are techniques that produce range data , volume data , 3D models , 4D light fields , 4D, 6D, or 8D BRDFs , or other high-dimensional image-based representations. Epsilon photography
5920-405: The type of color-separation mechanism: Special sensors are used in various applications such as creation of multi-spectral images , video laryngoscopes , gamma cameras , Flat-panel detectors and other sensor arrays for x-rays , microbolometer arrays in thermography , and other highly sensitive arrays for astronomy . While in general, digital cameras use a flat sensor, Sony prototyped
6000-734: The user to preview the scene; and the film or sensor, which captures the image. Several types of cameras exist, each suited to specific uses and offering unique capabilities. Single-lens reflex (SLR) cameras provide real-time, exact imaging through the lens. Large-format and medium-format cameras offer higher image resolution and are often used in professional and artistic photography. Compact cameras, known for their portability and simplicity, are popular in consumer photography. Rangefinder cameras , with separate viewing and imaging systems, were historically widely used in photojournalism. Motion picture cameras are specialized for filming cinematic content, while digital cameras , which became prevalent in
6080-428: The viewfinder prior to releasing the shutter for composing and focusing an image. When the shutter is released, the mirror swings up and away, allowing the exposure of the photographic medium , and instantly returns after the exposure is finished. No SLR camera before 1954 had this feature, although the mirror on some early SLR cameras was entirely operated by the force exerted on the shutter release and only returned when
6160-455: Was a marked increase in accessibility to cinematography for amateurs with Eastman Kodak's production of the first 16-mm and 8-mm reversal safety films. The World War II era saw a focus on the development of specialized aerial reconnaissance and instrument-recording equipment, even as the overall pace of non-military camera innovation slowed. In the second half of the century, Japanese manufacturers in particular advanced camera technology. From
6240-406: Was fairly straightforward to fabricate a series of MOS capacitors in a row, they connected a suitable voltage to them so that the charge could be stepped along from one to the next. The CCD is a semiconductor circuit that was later used in the first digital video cameras for television broadcasting . Early CCD sensors suffered from shutter lag . This was largely resolved with the invention of
6320-698: Was later improved by a group of scientists at the NASA Jet Propulsion Laboratory in 1993. By 2007, sales of CMOS sensors had surpassed CCD sensors. By the 2010s, CMOS sensors largely displaced CCD sensors in all new applications. The first commercial digital camera , the Cromemco Cyclops in 1975, used a 32×32 MOS image sensor. It was a modified MOS dynamic RAM ( DRAM ) memory chip . MOS image sensors are widely used in optical mouse technology. The first optical mouse, invented by Richard F. Lyon at Xerox in 1980, used
6400-504: Was proposed by G. Weckler in 1968. This was the basis for the PPS. These early photodiode arrays were complex and impractical, requiring selection transistors to be fabricated within each pixel, along with on-chip multiplexer circuits. The noise of photodiode arrays was also a limitation to performance, as the photodiode readout bus capacitance resulted in increased noise level. Correlated double sampling (CDS) could also not be used with
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