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  • Electric Guitar

    An electric guitar is a guitar that requires external electric sound amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickups to convert the vibration of its strings into electrical signals, which ultimately are reproduced as sound by loudspeakers. The sound is sometimes shaped or electronically altered to achieve different timbres or tonal qualities via amplifier settings or knobs on the guitar. Often, this is done through the use of effects such as reverbdistortion and “overdrive”; the latter is considered to be a key element of electric blues guitar music and jazzrock and heavy metal guitar playing. Designs also exist combining attributes of electric and acoustic guitars: the semi-acoustic and acoustic-electric guitars.

    Invented in 1932, the electric guitar was adopted by jazz guitar players, who wanted to play single-note guitar solos in large big band ensembles. Early proponents of the electric guitar on record include Les PaulEddie DurhamGeorge BarnesLonnie JohnsonSister Rosetta TharpeT-Bone Walker, and Charlie Christian. During the 1950s and 1960s, the electric guitar became the most important instrument in popular music.[1] It has evolved into an instrument that is capable of a multitude of sounds and styles in genres ranging from pop and rock to folk to country musicblues and jazz. It served as a major component in the development of electric bluesrock and rollrock musicheavy metal music and many other genres of music.

    Electric guitar design and construction varies greatly in the shape of the body and the configuration of the neck, bridge, and pickups. Guitars may have a fixed bridge or a spring-loaded hinged bridge, which lets players “bend” the pitch of notes or chords up or down, or perform vibrato effects. The sound of an electric guitar can be modified by new playing techniques such as string bendingtapping, and hammering-on, using audio feedback, or slide guitar playing.

    There are several types of electric guitar. Early forms were hollow-body semi-acoustic guitars, while solid body guitars developed later. String configurations include the six-string guitar (the most common type), which is usually tuned E, A, D, G, B, E, from lowest to highest strings; the seven-string guitar, which typically adds a low B string below the low E; the eight-string guitar, which typically adds a low E or F# string below the low B; and the twelve-string guitar, which has six two-string courses similar to a mandolin.

    In rock, the electric guitar is often used in two roles: as a rhythm guitar, which plays the chord sequences or progressions, and riffs, and sets the beat (as part of a rhythm section); and as a lead guitar, which provides instrumental melody lines, melodic instrumental fill passages, and solos. In a small group, such as a power trio, one guitarist may switch between both roles; in larger groups there is often a rhythm guitarist and a lead guitarist.

    History

    [edit]

    The “Frying Pan”, 1932

    Many experiments with electrically amplifying the vibrations of a string instrument were made dating back to the early part of the 20th century. Patents from the 1910s show telephone transmitters were adapted and placed inside violins and banjos to amplify the sound. Hobbyists in the 1920s used carbon button microphones attached to the bridge; however, these detected vibrations from the bridge on top of the instrument, resulting in a weak signal.[2]

    Electric guitars were originally designed by acoustic guitar makers and instrument manufacturers. The demand for amplified guitars began during the big band era; as orchestras increased in size, guitar players soon realized the necessity in guitar amplification and electrification.[3] The first electric guitars used in jazz were hollow archtop acoustic guitar bodies with electromagnetic transducers.

    The first electrically amplified stringed instrument to be marketed commercially was a cast aluminium lap steel guitar nicknamed the “Frying Pan” designed in 1931 by George Beauchamp, the general manager of the National Stringed Instrument Corporation, with Paul Barth, who was vice president.[4] George Beauchamp, along with Adolph Rickenbacker, invented the electromagnetic pickups.[5] Coils that were wrapped around a magnet would create an electromagnetic field that converted the vibrations of the guitar strings into electrical signals, which could then be amplified. Commercial production began in late summer of 1932 by the Ro-Pat-In Corporation (ElectroPatent-Instrument Company), in Los Angeles,[6][7] a partnership of Beauchamp, Adolph Rickenbacker (originally Rickenbacher), and Paul Barth.[8]

    In 1934, the company was renamed the Rickenbacker Electro Stringed Instrument Company. In that year Beauchamp applied for a United States patent for an Electrical Stringed Musical Instrument and the patent was later issued in 1937.[9][10][11][12] By the time it was patented, other manufacturers were already making their own electric guitar designs.[13] Early electric guitar manufacturers include Rickenbacker in 1932; Dobro in 1933; National, AudioVox and Volu-tone in 1934; VegaEpiphone (Electrophone and Electar), and Gibson in 1935 and many others by 1936.

    Electro-Spanish by Ken Roberts, 1935

    By early-mid 1935, Electro String Instrument Corporation had achieved success with the “Frying Pan”, and set out to capture a new audience through its release of the Electro-Spanish Model B and the Electro-Spanish Ken Roberts, which was the first full 25-inch scale electric guitar ever produced.[14][9][10][11][12] The Electro-Spanish Ken Roberts was revolutionary for its time, providing players a full 25-inch scale, with easy access to 17 frets free of the body.[15] Unlike other lap-steel electrified instruments produced during the time, the Electro-Spanish Ken Roberts was designed to play while standing upright with the guitar on a strap, as with acoustic guitars.[15] The Electro-Spanish Ken Roberts was also the first instrument to feature a hand-operated vibrato as a standard arrangement,[15] a device called the “Vibrola”, invented by Doc Kauffman.[15] [16] It is estimated that fewer than 50 Electro-Spanish Ken Roberts were constructed between 1933 and 1937; fewer than 10 are known to survive today.[9][10][11][12]

    The solid-body electric guitar is made of solid wood, without functionally resonating air spaces. The first solid-body Spanish standard guitar was offered by Vivi-Tone no later than 1934. This model featured a guitar-shaped body of a single sheet of plywood affixed to a wood frame. Another early, substantially solid Spanish electric guitar, called the Electro Spanish, was marketed by the Rickenbacker guitar company in 1935 and made of Bakelite. By 1936, the Slingerland company introduced a wooden solid-body electric model, the Slingerland Songster 401 (and a lap steel counterpart, the Songster 400).

    Gibson’s first production electric guitar, marketed in 1936, was the ES-150 model (“ES” for “Electric Spanish”, and “150” reflecting the $150 price of the instrument, along with matching amplifier). The ES-150 guitar featured a single-coil, hexagonally shaped “bar” pickup, which was designed by Walt Fuller. It became known as the “Charlie Christian” pickup (named for the jazz guitarist who was among the first to perform with the ES-150 guitar). The ES-150 achieved some popularity but suffered from unequal loudness across the six strings.

    A functioning solid-body electric guitar was designed and built in 1940 by Les Paul from an Epiphone acoustic archtop as an experiment. His “log guitar” — a wood post with a neck attached and two hollow-body halves attached to the sides for appearance only — shares nothing in common for design or hardware with the solid-body Gibson Les Paul, designed by Ted McCarty and introduced in 1952.

    The feedback associated with amplified hollow-bodied electric guitars was understood long before Paul’s “log” was created in 1940; Gage Brewer’s Ro-Pat-In of 1932 had a top so heavily reinforced that it essentially functioned as a solid-body instrument.[2]

    Types

    [edit]

    Solid-body

    [edit]

    The Fender Stratocaster has one of the most often emulated electric guitar shapes[17][18]

    Unlike acoustic guitars, solid-body electric guitars have no vibrating soundboard to amplify string vibration. Instead, solid-body instruments depend on electric pickups, and an amplifier (“amp”) and speaker. The solid body ensures that the amplified sound reproduces the string vibration alone, thus avoiding the wolf tones and unwanted feedback[19] associated with amplified acoustic guitars. These guitars are generally made of hardwood covered with a hard polymer finish, often polyester or lacquer. In large production facilities, the wood is stored for three to six months in a wood-drying kiln before being cut to shape. Premium custom-built guitars are frequently made with much older (thus fully dried, cured and stabilized, that is to say, less prone to deformation), hand-selected wood.

    One of the first solid-body guitars was invented by Les PaulGibson did not present their Gibson Les Paul guitar prototypes to the public, as they did not believe the solid-body style would catch on. Another early solid-body Spanish style guitar, resembling what would become Gibson’s Les Paul guitar a decade later, was developed in 1941 by O.W. Appleton, of Nogales, Arizona.[20] Appleton made contact with both Gibson and Fender but was unable to sell the idea behind his “App” guitar to either company.[21] In 1946, Merle Travis commissioned steel guitar builder Paul Bigsby to build him a solid-body Spanish-style electric.[22] Bigsby delivered the guitar in 1948. The first mass-produced solid-body guitar was Fender Esquire and Fender Broadcaster (later to become the Fender Telecaster), first made in 1950, five years after Les Paul made his prototype. The Gibson Les Paul appeared soon after to compete with the Broadcaster.[23] Another notable solid-body design is the Fender Stratocaster, which was introduced in 1954 and became extremely popular among musicians in the 1960s and 1970s for its wide tonal capabilities and more comfortable ergonomics than other models. Different styles of guitar have different pick-up styles, the main being 2 or 3 “single-coil” pick-ups or a double humbucker, with the Stratocaster being a triple single-coil guitar.

    The history of electric guitars has been summarized by Guitar World magazine, and the earliest electric guitar on their top 10 list is the Ro-Pat-In Electro A-25 “Frying Pan” (1932) described as “The first-fully functioning solid-body electric guitar to be manufactured and sold”.[24] It was the first electric guitar used in a publicly promoted performance, performed by Gage Brewer in Wichita, Kansas in October 1932.[25][26][27] The most recent electric guitar on this list was the Ibanez Jem (1987) which featured “24 frets”, an impossibly thin neck” and was “designed to be the ultimate shredder machine”. Numerous other important electric guitars are on the list, including Gibson ES-150 (1936), Fender Telecaster (1951), Gibson Les Paul (1952), Gretsch 6128 Duo Jet (1953), Fender Stratocaster (1954), Rickenbacker 360/12 (1964), Van Halen Frankenstrat (1975), Paul Reed Smith Custom (1985) many of these guitars were “successors” to earlier designs.[24] Electric guitar designs eventually became culturally important and visually iconic, with various model companies selling miniature model versions of particularly famous electric guitars, for example, the Gibson SG used by Angus Young from the group AC/DC.

    Chambered-body

    [edit]

    Some otherwise solid-bodied guitars, such as the Gibson Les Paul Supreme, the PRS Singlecut, and the Fender Telecaster Thinline, are built with hollow chambers in the body. These chambers are designed to not interfere with the critical bridge and string anchor point on the solid body. In the case of Gibson and PRS, these are called chambered bodies. The motivation for this may be to reduce weight, to achieve a semi-acoustic tone (see below) or both.[28][29][30]

    Semi-acoustic 

    [edit]

    Main article: Semi-acoustic guitar

    Epiphone semi-acoustic hollow-body guitar

    Semi-acoustic guitars have a hollow body similar to an acoustic guitar and electromagnetic pickups mounted directly into the body. They work in a similar way to solid-body electric guitars except that because the hollow body also vibrates, the pickups convert a combination of string and body vibration into an electrical signal. Many models, known as semi-hollow bodies, have a solid block running through the middle of the soundbox designed to reduce acoustic feedback. They do not provide enough acoustic volume for live performance, but they can be used unplugged for quiet practice. Semi-acoustic guitars are noted for being able to provide a sweet, plaintive, or funky tone. They are used in many genres, including jazz, blues, funk, sixties pop, and indie rock. They generally have cello-style F-shaped sound holes, which can be blocked off to further reduce feedback. Whereas chambered guitars are made, like solid-body guitars, from a single block of wood, semi-acoustic guitar bodies are made from multiple pieces of wood in an archtop form, a method of construction different from the typical steel string acoustic guitar. The top is formed from a moderately thick piece of wood which is then carved into a thin outward-curving shape, whereas conventional acoustic guitars have a thin, flat top.

    Electric acoustic

    [edit]

    Main article: Acoustic-electric guitar

    Some steel-string acoustic guitars include a built-in system to electrically amplify their output without altering their tone as an alternative to using a separate microphone. The system may consist of piezoelectric pickups mounted under the bridge, or a low-mass microphone (usually a condenser mic) inside the body of the guitar that converts the vibrations in the body into electronic signals. Combinations of these types of pickups may be used, with an integral mixer/preamp/graphic equalizer. Such instruments are called electric acoustic guitars. They are regarded as acoustic guitars rather than electric guitars because the pickups do not produce a signal directly from the vibration of the strings, but rather from the vibration of the guitar top or body, and the amplification of the sound merely increases volume, not alters tone.

    Construction

    [edit]

    This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources in this section. Unsourced material may be challenged and removed. (May 2015) (Learn how and when to remove this message)
    1. Headstock
    1.1 machine heads
    1.2 truss rod cover
    1.3 string guide
    1.4 nut
    2. Neck
    2.1 fretboard
    2.2 inlay fret markers
    2.3 frets
    2.4 neck joint
    3. Body
    3.1 “neck” pickup
    3.2 “bridge” pickup
    3.3 saddles
    3.4 bridge
    3.5 fine tuners and tailpiece assembly
    3.6 whammy bar (vibrato arm)
    3.7 pickup selector switch
    3.8 volume and tone control knobs
    3.9 output connector (output jack)(TS)
    3.10 strap buttons
    4. Strings
    4.1 bass strings
    4.2 treble strings

    Electric guitar design and construction vary greatly in the shape of the body and the configuration of the neck, bridge, and pickups. However, some features are present on most guitars. The photo below shows the different parts of an electric guitar. The headstock (1) contains the metal machine heads (1.1), which use a worm gear for tuning. The nut (1.4)—a thin fret-like strip of metal, plastic, graphite, or bone—supports the strings at the headstock end of the instrument. The frets (2.3) are thin metal strips that stop the string at the correct pitch when the player pushes a string against the fingerboard. The truss rod (1.2) is a metal rod (usually adjustable) that counters the tension of the strings to keep the neck straight. Position markers (2.2) provide the player with a reference to the playing position on the fingerboard.[31]

    The neck and fretboard (2.1) extend from the body. At the neck joint (2.4), the neck is either glued or bolted to the body. The body (3) is typically made of wood with a hard, polymerized finish. Strings vibrating in the magnetic field of the pickups (3.1, 3.2) produce an electric current in the pickup winding that passes through the tone and volume controls (3.8) to the output jack. Some guitars have piezo pickups, in addition to or instead of magnetic pickups.

    Some guitars have a fixed bridge (3.4). Others have a spring-loaded hinged bridge called a vibrato bartremolo bar, or whammy bar, which lets players bend notes or chords up or down in pitch or perform a vibrato embellishment. A plastic pickguard on some guitars protects the body from scratches or covers the control cavity, which holds most of the wiring. The degree to which the choice of woods and other materials in the solid-guitar body (3) affects the sonic character of the amplified signal is disputed. Many believe it is highly significant, while others think the difference between woods is subtle. In acoustic and archtop guitars, wood choices more clearly affect tone.

    Woods typically used in solid-body electric guitars include alder (brighter, but well rounded), swamp ash (similar to alder, but with more pronounced highs and lows), mahogany (dark, bassy, warm), poplar (similar to alder), and basswood (very neutral).[32][33][34] Maple, a very bright tonewood,[34] is also a popular body wood but is very heavy. For this reason, it is often placed as a “cap” on a guitar made primarily of another wood. Cheaper guitars are often made of cheaper woods, such as plywoodpine, or agathis—not true hardwoods—which can affect durability and tone. Though most guitars are made of wood, any material may be used. Materials such as plastic, metal, and even cardboard have been used in some instruments.

    The guitar output jack typically provides a monaural signal. Many guitars with active electronics use a jack with an extra contact normally used for stereo. These guitars use the extra contact to break the ground connection to the on-board battery to preserve battery life when the guitar is unplugged. These guitars require a mono plug to close the internal switch and connect the battery to ground. Standard guitar cables use a high-impedance 14 inch (6.35 mm) mono plug. These have a tip and sleeve configuration referred to as a TS phone connector. The voltage is usually around 1 to 9 millivolts.

    A few guitars, such as Rickenbacker guitars equipped with Rick-O-Sound, feature stereo output. There are a variety of ways the “stereo” effect may be implemented. Commonly, but not exclusively, stereo guitars route the neck and bridge pickups to separate output buses on the guitar. A stereo cable then routes each pickup to its signal chain or amplifier. For these applications, the most popular connector is a high-impedance 14 inch (6.35 mm) plug with a tip, ring, and sleeve configuration, also known as a TRS phone connector. Some studio instruments, notably certain Gibson Les Paul models, incorporate a low-impedance three-pin XLR connector for balanced audio. Many exotic arrangements and connectors exist that support features such as midi and hexaphonic pickups.

    Bridge and tailpiece systems

    [edit]

    The bridge and tailpiece, while serving separate purposes, work closely together to affect playing style and tone. There are four basic types of bridge and tailpiece systems on electric guitars. Within these four types are many variants.

    hard-tail guitar bridge anchors the strings at or directly behind the bridge and is fastened securely to the top of the instrument.[35] These are common on carved-top guitars, such as the Gibson Les Paul and the Paul Reed Smith models, and on slab-body guitars, such as the Music Man Albert Lee and Fender guitars that are not equipped with a vibrato arm.

    floating or trapeze tailpiece (similar to a violin‘s) fastens to the body at the base of the guitar. These appear on RickenbackersGretschesEpiphones, a wide variety of archtop guitars, particularly jazz guitars, and the 1952 Gibson Les Paul.[36]

    Pictured is a tremolo arm or vibrato tailpiecestyle bridge and tailpiece system, often called a whammy bar or trem. It uses a lever (“vibrato arm”) attached to the bridge that can temporarily slacken or tighten the strings to alter the pitch. A player can use this to create a vibrato or a portamento effect. Early vibrato systems were often unreliable and made the guitar go out of tune easily. They also had a limited pitch range. Later Fender designs were better, but Fender held the patent on these, so other companies used older designs for many years.

    Detail of a Squier-made Fender Stratocaster. Note the vibrato arm, the 3 single-coil pickups, the volume and tone knobs.

    With the expiration of the Fender patent on the Stratocaster-style vibrato, various improvements on this type of internal, multi-spring vibrato system are now available. Floyd Rose introduced one of the first improvements on the vibrato system in many years when, in the late 1970s, he experimented with “locking” nuts and bridges that prevent the guitar from losing tuning, even under heavy vibrato bar use.

    Tune-o-matic with “strings through the body” construction (without stopbar)

    The fourth type of system employs string-through body anchoring. The strings pass over the bridge saddles, then through holes through the top of the guitar body to the back. The strings are typically anchored in place at the back of the guitar by metal ferrules. Many believe this design improves a guitar’s sustain and timbre. A few examples of string-through body guitars are the Fender Telecaster Thinline, the Fender Telecaster Deluxe, the B.C. Rich IT Warlock and Mockingbird, and the Schecter Omen 6 and 7 series.

    Pickups

    [edit]

    Main article: Pickup (music technology)

    Pickups on a Fender Squier “Fat Strat” guitar—a “humbucker” pickup on the left and two single-coil pickups on the right.

    Compared to an acoustic guitar, which has a hollow body, electric guitars make much less audible sound when their strings are plucked, so electric guitars are normally plugged into a guitar amplifier and speaker. When an electric guitar is played, string movement produces a signal by generating (i.e., inducing) a small electric current in the magnetic pickups, which are magnets wound with coils of very fine wire. The signal passes through the tone and volume circuits to the output jack, and through a cable to an amplifier.[37] The current induced is proportional to such factors as string density and the amount of movement over the pickups.

    Because of their natural qualities, magnetic pickups tend to pick up ambient, usually unwanted electromagnetic interference or EMI.[38] This mains hum results in a tone of 50 or 60 cycles per second depending on the powerline frequency of the local alternating current supply.

    The resulting hum is particularly strong with single-coil pickups. Double-coil or “humbucker” pickups were invented as a way to reduce or counter the sound, as they are designed to “buck” (in the verb sense of oppose or resist) the hum, hence their name. The high combined inductance of the two coils also leads to the richer, “fatter” tone associated with humbucking pickups.

    Necks

    [edit]

    Roasted Maple guitar neck blanks with flame figure before shaping

    Electric guitar necks vary in composition and shape. The primary metric of guitar necks is the scale length, which is the vibrating length of the strings from nut to bridge. A typical Fender guitar uses a 25.5-inch (65 cm) scale length, while Gibson uses a 24.75-inch (62.9 cm) scale length in their Les Paul. While the scale length of the Les Paul is often described as 24.75 inches, it has varied through the years by as much as a half inch.[39]

    Frets are positioned proportionally to scale length—the shorter the scale length, the closer the fret spacing. Opinions vary regarding the effect of scale length on tone and feel. Popular opinion holds that longer scale length contributes to greater amplitude. Reports of playing feel are greatly complicated by the many factors involved in this perception. String gauge and design, neck construction and relief, guitar setup, playing style, and other factors contribute to the subjective impression of playability or feel.

    A bolt-on neck

    Necks are described as bolt-onset-in, or neck-through, depending on how they attach to the body. Set-in necks are glued to the body at the factory. This is the traditional type of joint. Leo Fender pioneered bolt-on necks on electric guitars to facilitate easy adjustment and replacement. Neck-through instruments extend the neck to the length of the instrument so that it forms the center of the body. While a set-in neck can be carefully unglued by a skilled luthier, and a bolt-on neck can simply be unscrewed, a neck-through design is difficult or even impossible to repair, depending on the damage. Historically, the bolt-on style has been more popular for ease of installation and adjustment. Since bolt-on necks can be easily removed, there is an after-market in replacement bolt-on necks from companies such as Warmoth and Mighty Mite. Some instruments—notably most Gibson models—continue to use set-in glued necks. Neck-through bodies are somewhat more common in bass guitars.

    Materials for necks are selected for dimensional stability and rigidity,[40] and some allege that they influence tone. Hardwoods are preferred, with maplemahogany, and ash topping the list. The neck and fingerboard can be made from different materials; for example, a guitar may have a maple neck with a rosewood or ebony fingerboard. Today there are expensive and budget guitars exploring other options for fretboard wood for instance Pau-Ferro, both for availability and cheap price while still maintaining quality.[41] In the 1970s, designers began to use exotic human-made materials such as aircraft-grade aluminumcarbon fiber, and ebonol. Makers known for these unusual materials include John VelenoTravis BeanGeoff Gould, and Alembic.

    Two headless .strandberg* Boden Plini model guitars with differing construction methods. On the left is neck-through construction with a quarter-sawn Roasted Maple neck and Swamp Ash wings. On the right is a chamfered bolt-on quarter-sawn Mahogany neck and Mahogany body. Both necks have visible carbon reinforcement strips.

    Aside from possible engineering advantages, some feel that with the rising cost of rare tonewoods, human-made materials may be economically preferable and more ecologically sensitive. However, wood remains popular in production instruments, though sometimes in conjunction with new materials. Vigier guitars, for example, use a wooden neck reinforced by embedding a light, carbon fiber rod in place of the usual heavier steel bar or adjustable steel truss rod. After-market necks made entirely from carbon fiber fit existing bolt-on instruments. Few, if any, extensive formal investigations have been widely published that confirm or refute claims over the effects of different woods or materials on the electric guitar sound.

    A neck-through bass guitar

    Several neck shapes appear on guitars, including shapes known as C necks, U necks, and V necks. These refer to the cross-sectional shape of the neck (especially near the nut). Several sizes of fret wire are available, with traditional players often preferring thin frets, and metal shredders liking thick frets. Thin frets are considered better for playing chords, while thick frets allow lead guitarists to bend notes with less effort.

    An electric guitar with a folding neck called the “Foldaxe” was designed and built for Chet Atkins by Roger C. Field.[42] Steinberger guitars developed a line of exotic, carbon fiber instruments without headstocks, with tuning done on the bridge instead.

    Fingerboards vary as much as necks. The fingerboard surface usually has a cross-sectional radius that is optimized to accommodate finger movement for different playing techniques. Fingerboard radius typically ranges from nearly flat (a very large radius) to radically arched (a small radius). The vintage Fender Telecaster, for example, has a typical small radius of approximately 7.25 inches (18.4 cm). Some manufacturers have experimented with fret profile and material, fret layout, number of frets, and modifications of the fingerboard surface for various reasons. Some innovations were intended to improve playability by ergonomic means, such as Warmoth Guitars’ compound radius fingerboard. Scalloped fingerboards added enhanced microtonality during fast legato runs. Fanned frets intend to provide each string with an optimal playing tension and enhanced musicality. Some guitars have no frets, while others, like the Gittler guitar, have no neck in the traditional sense.

  •  Digital Camera

    digital camera, also called a digicam,[1] is a camera that captures photographs in digital memory. Most cameras produced today are digital,[2] largely replacing those that capture images on photographic film or film stock. Digital cameras are now widely incorporated into mobile devices like smartphones with the same or more capabilities and features of dedicated cameras.[3] High-end, high-definition dedicated cameras are still commonly used by professionals and those who desire to take higher-quality photographs.[4]

    Digital and digital movie cameras share an optical system, typically using a lens with a variable diaphragm to focus light onto an image pickup device.[5] The diaphragm and shutter admit a controlled amount of light to the image, just as with film, but the image pickup device is electronic rather than chemical. However, unlike film cameras, digital cameras can display images on a screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving videos with sound. Some digital cameras can crop and stitch pictures and perform other kinds of image editing.[6][7]

    History

    [edit]

    Further information: History of the camera § Digital camerasDigital imagingDigital single-lens reflex camera, and Camera phone

    The first semiconductor image sensor was the charge-coupled device (CCD), invented by Willard S. Boyle and George E. Smith at Bell Labs in 1969,[8] based on MOS capacitor technology.[9] The NMOS active-pixel sensor was later invented by Tsutomu Nakamura‘s team at Olympus in 1985,[10][11][12] which led to the development of the CMOS active-pixel sensor (CMOS sensor) at the NASA Jet Propulsion Laboratory in 1993.[13][11]

    In the 1960s, Eugene F. Lally of the Jet Propulsion Laboratory was thinking about how to use a mosaic photosensor to capture digital images. His idea was to take pictures of the planets and stars while travelling through space to give information about the astronauts’ position.[14] As with Texas Instruments employee Willis Adcock’s filmless camera (US patent 4,057,830) in 1972,[15] the technology had yet to catch up with the concept.

    In 1972, the Landsat 1 satellite’s multispectral scanner (MSS) started taking digital images of Earth. The MSS, designed by Virginia Norwood at Hughes Aircraft Company starting in 1969, captured and transmitted image data from green, red, and two infrared bands with 6 bits per channel, using a mechanical rocking mirror and an array of 24 detectors. Operating for six years, it transmitted more than 300,000 digital photographs of Earth while orbiting the planet about 14 times per day.

    Also in 1972, Thomas McCord from MIT and James Westphal from Caltech together developed a digital camera for use with telescopes. Their 1972 “photometer-digitizer system” used an analog-to-digital converter and a digital frame memory to store 256 x 256-pixel images of planets and stars, which were then recorded on digital magnetic tape.  CCD sensors were not yet commercially available, and the camera used a silicon diode vidicon tube detector, which was cooled using dry ice to reduce dark current, allowing exposure times of up to one hour.   

    The Cromemco Cyclops was an all-digital camera introduced as a commercial product in 1975. Its design was published as a hobbyist construction project in the February 1975 issue of Popular Electronics magazine. It used a 32×32 metal–oxide–semiconductor (MOS) image sensor, which was a modified MOS dynamic RAM (DRAMmemory chip.[16]

    Steven Sasson, an engineer at Eastman Kodak, built a self-contained electronic camera that used a monochrome Fairchild CCD image sensor in 1975.[17][18][19] Around the same time, Fujifilm began developing CCD technology in the 1970s.[20] Early uses were mainly military and scientific, followed by medical and news applications.[21]

    The first filmless SLR (single lens reflex) camera was publicly demonstrated by Sony in August 1981. The Sony “Mavica” (magnetic still video camera) used a color-striped 2/3″ format CCD sensor with 280K pixels, along with analogue video signal processing and recording.[22] The Mavica electronic still camera recorded FM-modulated analog video signals on a newly developed 2″ magnetic floppy disk, dubbed the “Mavipak”. The disk format was later standardized as the “Still Video Floppy”, or “SVF”.

    The Canon RC-701, introduced in May 1986, was the first SVF camera (and the first electronic SLR camera) sold in the US. It employed an SLR viewfinder, included a 2/3″ format color CCD sensor with 380K pixels, and was sold along with a removable 11-66mm and 50-150mm zoom lens.[23]  

    Over the next few years, many other companies began selling SVF cameras. These analog electronic cameras included the Nikon QV-1000C, which had an SLR viewfinder and a 2/3″ format monochrome CCD sensor with 380K pixels and recorded analog black-and-white images on a Still Video Floppy.[24][25]

    At Photokina 1988, Fujifilm introduced the FUJIX DS-1P, the first fully digital camera, which recorded digital images using a semiconductor memory card. The camera’s memory card had a capacity of 2 MB of SRAM (static random-access memory) and could hold up to ten photographs. In 1989, Fujifilm released the FUJIX DS-X, the first fully digital camera to be commercially released.[20] In 1996, Toshiba‘s 40 MB flash memory card was adopted for several digital cameras.[26]

    The first commercial camera phone was the Kyocera Visual Phone VP-210, released in Japan in May 1999.[27] It was called a “mobile videophone” at the time,[28] and had a 110,000-pixel front-facing camera.[27] It stored up to 20 JPEG digital images, which could be sent over e-mail, or the phone could send up to two images per second over Japan’s Personal Handy-phone System (PHS) cellular network.[27] The Samsung SCH-V200, released in South Korea in June 2000, was also one of the first phones with a built-in camera. It had a TFT liquid-crystal display (LCD) and stored up to 20 digital photos at 350,000-pixel resolution. However, it could not send the resulting image over the telephone function but required a computer connection to access photos.[29] The first mass-market camera phone was the J-SH04, a Sharp J-Phone model sold in Japan in November 2000.[30][29] It could instantly transmit pictures via cell phone telecommunication.[31] By the mid-2000s, higher-end cell phones had an integrated digital camera, and by the early 2010s, almost all smartphones had an integrated digital camera.[32]

    Image sensors

    [edit]

    Further information: Image sensor

    The two major types of digital image sensors are CCD and CMOS. A CCD sensor has one amplifier for all the pixels, while each pixel in a CMOS active-pixel sensor has its own amplifier.[33] Compared to CCDs, CMOS sensors use less power. Cameras with a small sensor use a back-side-illuminated CMOS (BSI-CMOS) sensor. The image processing capabilities of the camera determine the outcome of the final image quality much more than the sensor type.[34][35]

    Sensor resolution

    [edit]

    The resolution of a digital camera is often limited by the image sensor that turns light into discrete signals. The brighter the image at a given point on the sensor, the larger the value that is read for that pixel. Depending on the physical structure of the sensor, a color filter array may be used, which requires demosaicing to recreate a full-color image. The number of pixels in the sensor determines the camera’s “pixel count“. In a typical sensor, the pixel count is the product of the number of rows and the number of columns. For example, a 1,000 by 1,000-pixel sensor would have 1,000,000 pixels, or 1 megapixel.

    Resolution options

    [edit]

    Firmwares’ resolution selector allows the user to optionally lower the resolution to reduce the file size per picture and extend lossless digital zooming. The bottom resolution option is typically 640×480 pixels (0.3 megapixels).[36]

    A lower resolution extends the number of remaining photos in free space, postponing the exhaustion of space storage, which is of use where no further data storage device is available and for captures of lower significance, where the benefit from less space storage consumption outweighs the disadvantage from reduced detail.[37]

    Image sharpness

    [edit]

    An image’s sharpness is presented through the crisp detail, defined lines, and its depicted contrast. Sharpness is a factor of multiple systems throughout the DSLR camera by its ISO, resolution, lens, and the lens settings, the environment of the image, and its post-processing. Images have a possibility of being too sharp, but they can never be too in focus.

    A digital camera resolution is determined by a digital sensor. The digital sensor indicates a high level of sharpness can be produced through the amount of noise and grain that is tolerated through the lens of the camera. Resolution within the field of digital stills and digital movies is indicated through the camera’s ability to determine detail based on the distance, which is then measured by frame size, pixel type, number, and organization. Although some DSLR cameras have limited resolutions, it is almost impossible to not have the proper sharpness for an image. The ISO choice when taking a photo affects the quality of the image, as high ISO settings equate to an image that is less sharp due to the increased amount of noise allowed into the image, along with too little noise, which can also produce an image that is not sharp.[38]

    Methods of image capture

    [edit]

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    At the heart of a digital camera is a CCD or a CMOS image sensor.
    Digital camera, partially disassembled. The lens assembly (bottom right) is removed but the sensor (top right) can still capture an image, as seen on the LCD screen (bottom left).

    Since the first digital backs were introduced, there have been three main methods of capturing the image, each based on the hardware configuration of the sensor and color filters.

    Single-shot capture systems use either one sensor chip with a Bayer filter mosaic, or three separate image sensors (one each for the primary additive colors red, green, and blue) which are exposed to the same image via a beam splitter (see Three-CCD camera).

    Multi-shot exposes the sensor to the image in a sequence of three or more openings of the lens aperture. There are several methods of application of the multi-shot technique. The most common was originally to use a single image sensor with three filters passed in front of the sensor in sequence to obtain the additive color information. Another multiple-shot method is called microscanning. This method uses a single sensor chip with a Bayer filter and physically moves the sensor on the focus plane of the lens to construct a higher resolution image than the native resolution of the chip. A third version combines these two methods without a Bayer filter on the chip.

    The third method is called scanning because the sensor moves across the focal plane much like the sensor of an image scanner. The linear or tri-linear sensors in scanning cameras utilize only a single line of photosensors, or three lines for the three colors. Scanning may be accomplished by moving the sensor (for example, when using color co-site sampling) or by rotating the whole camera. A digital rotating line camera offers images consisting of a total resolution that is very high.

    Improvements in single-shot cameras and image file processing at the beginning of the 21st century made single-shot cameras almost completely dominant, even in high-end commercial photography.

    Filter mosaics, interpolation, and aliasing

    [edit]

    The Bayer arrangement of color filters on the pixel array of an image sensor.

    Most current [timeframe?] consumer digital cameras use a Bayer filter mosaic in combination with an optical anti-aliasing filter to reduce the aliasing due to the reduced sampling of the different primary-color images. A demosaicing algorithm is used to interpolate color information to create a full array of RGB image data.

    Cameras that use a beam-splitter single-shot 3CCD approach, three-filter multi-shot approach, color co-site sampling or Foveon X3 sensor do not use anti-aliasing filters, nor demosaicing.


    Firmware in the camera, or a software in a raw converter program such as Adobe Camera Raw, interprets the raw data from the sensor to obtain a full-color image, because the RGB color model requires three intensity values for each pixel: one each for the red, green, and blue (other color models, when used, also require three or more values per pixel). A single sensor element cannot simultaneously record these three intensities, so a color filter array (CFA) must be used to selectively filter a particular color for each pixel.

    The Bayer filter pattern is a repeating 2×2 mosaic pattern of light filters, with green ones at opposite corners and red and blue in the other two positions. The high proportion of green takes advantage of the properties of the human visual system, which determines brightness mostly from green and is far more sensitive to brightness than to hue or saturation. Sometimes a 4-color filter pattern is used, often involving two different hues of green. This provides potentially more accurate color, but requires a slightly more complicated interpolation process.[39]

    The color intensity values not captured for each pixel can be interpolated from the values of adjacent pixels which represent the color being calculated.[40]

    Sensor size and angle of view

    [edit]

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    Cameras with digital image sensors that are smaller than the typical 35 mm film size have a smaller field or angle of view when used with a lens of the same focal length. This is because the angle of view is a function of both focal length and the sensor or film size used.

    Image illustrating crop factors for some common digital image sensor formats

    The crop factor is relative to the 35mm film format. If a smaller sensor is used, as in most digicams, the field of view is cropped by the sensor to smaller than the 35 mm full-frame format’s field of view. This narrowing of the field of view may be described as crop factor, a factor by which a longer focal length lens would be needed to get the same field of view on a 35 mm film camera. Full-frame digital SLRs utilize a sensor of the same size as a frame of 35 mm film.

    Common values for field of view crop in DSLRs using active pixel sensors include 1.3x for some Canon (APS-H) sensors, 1.5x for Sony APS-C sensors used by Nikon, Pentax and Konica Minolta and for Fujifilm sensors, 1.6 (APS-C) for most Canon sensors, ~1.7x for Sigma‘s Foveon sensors and 2x for Kodak and Panasonic 4/3-inch sensors currently used by Olympus and Panasonic. Crop factors for non-SLR consumer compact and bridge cameras are larger, frequently 4x or more.

    Further information: Image sensor format

    Relative sizes of sensors used in most current digital cameras.
    TypeWidth (mm)Height (mm)Size (mm²)
    1/3.6″4.003.0012.0
    1/3.2″4.543.4215.5
    1/3″4.803.6017.3
    1/2.7″5.374.0421.7
    1/2.5″5.764.2924.7
    1/2.3″6.164.6228.5
    1/2″6.404.8030.7
    1/1.8″7.185.3238.2
    1/1.7″7.605.7043.3
    2/3″8.806.6058.1
    1″12.89.6123
    4/3″18.013.5243
    APS-C25.116.7419
    35 mm3624864
    Back48361728

    Sensor resolution

    [edit]

    The resolution of a digital camera is often limited by the image sensor that turns light into discrete signals. The brighter the image at a given point on the sensor, the larger the value that is read for that pixel. Depending on the physical structure of the sensor, a color filter array may be used, which requires demosaicing to recreate a full-color image. The number of pixels in the sensor determines the camera’s “pixel count“. In a typical sensor, the pixel count is the product of the number of rows and the number of columns. Pixels are square and is often equal to 1, for example, a 1,000 by 1,000-pixel sensor would have 1,000,000 pixels, or 1 megapixel. On full-frame sensors (i.e., 24 mm 36 mm), some cameras propose images with 20–25 million pixels that were captured by 7.5–m photosites, or a surface that is 50 times larger.  [42]

    Cross section of a DSLR camera.

    Types of digital cameras

    [edit]

    Digital cameras come in a wide range of sizes, prices, and capabilities. In addition to general-purpose digital cameras, specialized cameras including multispectral imaging equipment and astrographs are used for scientific, military, medical, and other special purposes.

    Compacts

    [edit]

    The Sony DSC-W170 compact camera with lens assembly retracted
    Disassembled compact digital camera

    Compact cameras are intended to be portable (pocketable) and are particularly suitable for casual “snapshots“. Point-and-shoot cameras usually fall under this category.

    Many incorporate a retractable lens assembly that provides optical zoom. In most models, an auto-actuating lens cover protects the lens from elements. Most ruggedized or water-resistant models do not retract, and most with superzoom capability do not retract fully.

    Compact cameras are usually designed to be easy to use. Almost all include an automatic mode, or “auto mode”, which automatically makes all camera settings for the user. Some also have manual controls. Compact digital cameras typically contain a small sensor that trades-off picture quality for compactness and simplicity; images can usually only be stored using lossy compression (JPEG). Most have a built-in flash usually of low power, sufficient for nearby subjects. A few high-end compact digital cameras have a hotshoe for connecting to an external flash. Live preview is almost always used to frame the photo on an integrated LCD. In addition to being able to take still photographs almost all compact cameras have the ability to record video.

    Compacts often have macro capability and zoom lenses, but the zoom range (up to 30x) is generally enough for candid photography but less than is available on bridge cameras (more than 60x), or the interchangeable lenses of DSLR cameras available at a much higher cost.[43] Autofocus systems in compact digital cameras generally are based on a contrast-detection methodology using the image data from the live preview feed of the main imager. Some compact digital cameras use a hybrid autofocus system similar to what is commonly available on DSLRs.

    Typically, compact digital cameras incorporate a nearly silent leaf shutter into the lens but play a simulated camera sound for skeuomorphic purposes.

    For low cost and small size, these cameras typically use image sensor formats with a diagonal between 6 and 11 mm, corresponding to a crop factor between 7 and 4. This gives them weaker low-light performance, greater depth of field, generally closer focusing ability, and smaller components than cameras using larger sensors. Some cameras use a larger sensor including, at the high end, a pricey full-frame sensor compact camera, such as Sony Cyber-shot DSC-RX1, but have capability near that of a DSLR.

    A variety of additional features are available depending on the model of the camera. Such features include GPS, compass, barometers and altimeters.[44]

    Starting in 2010, some compact digital cameras can take 3D still photos.[45] These 3D compact stereo cameras can capture 3D panoramic photos with dual lens or even a single lens for playback on a 3D TV.

    In 2013, Sony released two add-on camera models without display, to be used with a smartphone or tablet, controlled by a mobile application via WiFi.[46]

    Rugged compacts

    [edit]

    Rugged compact cameras typically include protection against submersion, hot and cold conditions, shock, and pressure. Terms used to describe such properties include waterproof, freeze-proof, heatproof, shockproof, and crushproof, respectively. Nearly all major camera manufacturers have at least one product in this category. Some are waterproof to a considerable depth up to 100 feet (30 m);[47] others only 10 feet (3 m), but only a few will float. Ruggeds often lack some of the features of ordinary compact camera, but they have video capability and the majority can record sound. Most have image stabilization and built-in flash. Touchscreen LCD and GPS do not work underwater.

    Action cameras

    [edit]

    Further information: Action camera

    GoPro and other brands offer action cameras that are rugged, small, and can be easily attached to helmets, arms, bicycles, etc. Most have a wide angle and fixed focus and can take still pictures and video, typically with sound.

    360-degree cameras

    [edit]

    Main article: 360-degree camera

    The 360-degree camera can take picture or video 360 degrees using two lenses back-to-back and shooting at the same time. Some of the cameras are Ricoh Theta S, Nikon Keymission 360 and Samsung Gear 360. Nico360 was launched in 2016 and claimed as the world’s smallest 360-degree camera with size 46 x 46 x 28 mm (1.8 x 1.8 x 1.1 in) and price less than $200. With virtual reality mode built-in stitching, Wifi, and Bluetooth, live streaming can be done. Due to it also being water resistant, the Nico360 can be used as action camera.[48]

    Bridge cameras

    [edit]

    Sony DSC-H2

    Main article: Bridge camera

    Bridge cameras physically resemble DSLRs, and are sometimes called DSLR-shape or DSLR-like. They provide some similar features but, like compacts, they use a fixed lens and a small sensor. Some compact cameras have also PSAM mode.[clarification needed] Most use live preview to frame the image. Their usual autofocus is by the same contrast-detect mechanism as compacts, but many bridge cameras have a manual focus mode and some have a separate focus ring for greater control.

    The big physical size and small sensor allow superzoom and wide aperture. Bridge cameras generally include an image stabilization system to enable longer handheld exposures, sometimes better than DSLR for low light conditions.

    As of 2014, bridge cameras come in two principal classes in terms of sensor size, firstly the more traditional 1/2.3″ sensor (as measured by image sensor format) which gives more flexibility in lens design and allows for handholdable zoom from 20 to 24 mm (35 mm equivalent) wide angle all the way up to over 1000 mm supertele, and secondly a 1″ sensor that allows better image quality particularly in low light (higher ISO) but puts greater constraints on lens design, resulting in zoom lenses that stop at 200 mm (constant aperture, e.g. Sony RX10) or 400 mm (variable aperture, e.g. Panasonic Lumix FZ1000) equivalent, corresponding to an optical zoom factor of roughly 10 to 15.

    Some bridge cameras have a lens thread to attach accessories such as wide-angle or telephoto converters as well as filters such as UV or Circular Polarizing filter and lens hoods. The scene is composed by viewing the display or the electronic viewfinder (EVF). Most have a slightly longer shutter lag than a DSLR. Many of these cameras can store images in a raw format in addition to supporting JPEG.[a] The majority have a built-in flash, but only a few have a hotshoe.

    In bright sun, the quality difference between a good compact camera and a digital SLR is minimal but bridge cameras are more portable, cost less and have a greater zoom ability. Thus a bridge camera may better suit outdoor daytime activities, except when seeking professional-quality photos.[49]

    Mirrorless interchangeable-lens cameras

    [edit]

    Olympus OM-D E-M1 Mark II introduced 2016
    Nikon Z7 introduced 2018

    Main article: Mirrorless interchangeable-lens camera

    In late 2008, a new type of camera emerged, called a mirrorless interchangeable-lens camera. It is technically a DSLR camera that does not require a reflex mirror, a key component of the former. While a typical DSLR has a mirror that reflects light from the lens up to the optical viewfinder, in a mirrorless camera, there is no optical viewfinder. The image sensor is exposed to light at all times, giving the user a digital preview of the image either on the built-in rear LCD screen or an electronic viewfinder (EVF).[50]

    These are simpler and more compact than DSLRs due to not having a lens reflex system. MILCs, or mirrorless cameras for short, come with various sensor sizes depending on the brand and manufacturer, these include: a small 1/2.3 inch sensor, as is commonly used in bridge cameras such as the original Pentax Q (more recent Pentax Q versions have a slightly larger 1/1.7 inch sensor); a 1-inch sensor; a Micro Four Thirds sensor; an APS-C sensor found in Sony NEX series and α “DSLR-likes”, Fujifilm X seriesPentax K-01, and Canon EOS M; and some, such as the Sony α7, use a full frame (35 mm) sensor, with the Hasselblad X1D being the first medium format mirrorless camera. Some MILCs have a separate electronic viewfinder to compensate the lack of an optical one. In other cameras, the back display is used as the primary viewfinder in the same way as in compact cameras. One disadvantage of mirrorless cameras compared to a typical DSLR is its battery life due to the energy consumption of the electronic viewfinder, but this can be mitigated by a setting inside the camera in some models.[51] Many mirrorless cameras have a hotshoe.

    Olympus and Panasonic released many Micro Four Thirds cameras with interchangeable lenses that are fully compatible with each other without any adapter, while others have proprietary mounts. In 2014, Kodak released its first Micro Four Third system camera.[52]

    As of March 2014, mirrorless cameras are fast becoming appealing to both amateurs and professionals alike due to their simplicity, compatibility with some DSLR lenses, and features that match most DSLRs today.[53]

    Modular cameras

    [edit]

    Sony Alpha ILCE-QX1, an example of a modular, lens-style camera, introduced in 2014

    While most digital cameras with interchangeable lenses feature a lens-mount of some kind, there are also a number of modular cameras, where the shutter and sensor are incorporated into the lens module.

    The first such modular camera was the Minolta Dimâge V in 1996, followed by the Minolta Dimâge EX 1500 in 1998 and the Minolta MetaFlash 3D 1500 in 1999. In 2009, Ricoh released the Ricoh GXR modular camera.

    At CES 2013, Sakar International announced the Polaroid iM1836, an 18MP camera with 1″-sensor with interchangeable sensor-lens. An adapter for Micro Four Thirds, Nikon and K-mount lenses was planned to ship with the camera.[54]

    There are also a number of add-on camera modules for smartphones, they are called lens-style cameras (lens camera or smart lens). They contain all the essential components of a digital camera inside a DSLR lens-shaped module, hence the name, but lack any sort of viewfinder and most controls of a regular camera. Instead, they are connected wirelessly and/or mounted to a smartphone to be used as its display output and operate the camera’s various controls.

    Lens-style cameras include:

    • Sony Cyber-shot QX series “Smart Lens” or “SmartShot” cameras, announced and released in mid 2013 with the Cyber-shot DSC-QX10. In January 2014, a firmware update was announced for the DSC-QX10 and DSC-QX100.[55] In September 2014, Sony announced the Cyber-shot DSC-QX30 as well as the Alpha ILCE-QX1,[56][57] the former an ultrazoom with a built-in 30x optical zoom lens, the latter opting for an interchangeable Sony E-mount instead of a built-in lens.
    • Kodak PixPro smart lens camera series, announced in 2014. These include: the 5X optical zoom SL5, 10X optical zoom SL10, and the 25X optical zoom SL25; all featuring 16MP sensors and 1080p video recording, except for the SL5 which caps at 720p.[58]
    • ViviCam IU680 smart lens camera from Sakar-owned brand, Vivitar, announced in 2014.[59]
    • Olympus Air A01 lens camera, announced in 2014 and released in 2015, the lens camera is an open platform with an Android operating system and can detach into 2 parts (sensor module and lens), just like the Sony QX1, and all compatible Micro Four Thirds lenses can then be attached to the built-in lens mount of the camera’s sensor module.[60][61]

    Digital single-lens reflex cameras (DSLR)

    [edit]

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    Cutaway of an Olympus E-30 DSLR

    Main article: Digital single-lens reflex camera

    Digital single-lens reflex cameras (DSLR) is a camera with a digital sensor that utilizes a reflex mirror to split or direct light into the viewfinder to produce an image.[62] The reflex mirror finds the image by blocking light to the camera’s sensor and then reflecting it into the camera’s pentaprism which allows it to be seen through the viewfinder.[62] When the shutter release is fully pressed the reflex mirror pulls out horizontally below the pentaprism briefly darkening the viewfinder and then opening up the sensor for exposure which creates the photo.[62] The digital image is produced by the sensor which is an array of photoreceptors on a microchip capable of recording light values. Many modern DSLRs offer the ability for “live view” or the framing of the subject emitted from the sensor onto a digital screen, and many have a hotshoe.

    The sensor also known as a full-frame sensor is much larger than the other types, typically 18mm to 36mm on the diagonal (crop factor 2, 1.6, or 1).[62] The larger sensor permits more light to be received by each pixel; this, combined with the relatively large lenses provides superior low-light performance. For the same field of view and the same aperture, a larger sensor gives shallower focus. DSLRs can equip interchangeable lenses for versatility by removing it from the lens mount of the camera, typically a silver ring on the front side of DSLRs.[63] These lenses work in tandem with the mechanics of the DSLR to adjust aperture and focus. Autofocus is accomplished using sensors in the mirror box and on most modern lenses can be activated from the lens itself which will trigger upon shutter release.[62]

    Digital Still Cameras (DSC)

    [edit]

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    Digital Still Camera (DSC), such as the Sony DSC cameras, is a type of camera that does not use a reflex mirror. DSCs are like point-and-shoot cameras and are the most common type of cameras, due to their comfortable price and its quality.[citation needed]

    Here are a list of DSCs: List of Sony Cyber-shot cameras

    Fixed-mirror DSLT cameras

    [edit]

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    Cameras with fixed semi-transparent mirrors, also known as DSLT cameras, such as the Sony SLT cameras, are single-lens without a moving reflex mirror as in a conventional DSLR. A semi-transparent mirror transmits some of the light to the image sensor and reflects some of the light along the path to a pentaprism/pentamirror which then goes to an optical view finder (OVF) as is done with a reflex mirror in DSLR cameras. The total amount of light is not changed, just some of the light travels one path and some of it travels the other. The consequences are that DSLT cameras should shoot a half stop differently from DSLR. One advantage of using a DSLT camera is the blind moments a DSLR user experiences while the reflecting mirror is moved to send the light to the sensor instead of the viewfinder do not exist for DSLT cameras. Because there is no time at which light is not traveling along both paths, DSLT cameras get the benefit of continuous auto-focus tracking. This is especially beneficial for burst-mode shooting in low-light conditions and also for tracking when taking video.[citation needed]

    Digital rangefinders

    [edit]

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    Main article: Rangefinder camera § Digital rangefinder

    A rangefinder is a device to measure subject distance, with the intent to adjust the focus of a camera’s objective lens accordingly (open-loop controller). The rangefinder and lens focusing mechanism may or may not be coupled. In common parlance, the term “rangefinder camera” is interpreted very narrowly to denote manual-focus cameras with a visually-read out optical rangefinder based on parallax. Most digital cameras achieve focus through analysis of the image captured by the objective lens and distance estimation, if it is provided at all, is only a byproduct of the focusing process (closed-loop controller).[64]

    Line-scan camera systems

    [edit]

    Main article: line-scan camera

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    A San Francisco cable car, imaged using an Alkeria Necta N4K2-7C line scan camera with a shutter speed of 250 microseconds, or 4000 frames per second.

    A line-scan camera traditionally has a single row of pixel sensors, instead of a matrix of them. The lines are continuously fed to a computer that joins them to each other and makes an image.[65][66] This is most commonly done by connecting the camera output to a frame grabber which resides in a PCI slot of an industrial computer. The frame grabber acts to buffer the image and sometimes provide some processing before delivering to the computer software for processing. Industrial processes often require height and width measurements performed by digital line-scan systems.[67]

    Multiple rows of sensors may be used to make colored images, or to increase sensitivity by TDI (time delay and integration).

    Many industrial applications require a wide field of view. Traditionally maintaining consistent light over large 2D areas is quite difficult. With a line scan camera all that is necessary is to provide even illumination across the “line” currently being viewed by the camera. This makes sharp pictures of objects that pass the camera at high speed.

    Such cameras are also commonly used to make photo finishes, to determine the winner when multiple competitors cross the finishing line at nearly the same time. They can also be used as industrial instruments for analyzing fast processes.

    Line-scan cameras are also extensively used in imaging from satellites (see push broom scanner). In this case the row of sensors is perpendicular to the direction of satellite motion. Line-scan cameras are widely used in scanners. In this case, the camera moves horizontally.

    Further information: Rotating line camera and Strip photography

    Superzoom cameras

    [edit]

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    See also: List of superzoom cameras

    Digital superzoom cameras are digital cameras that can zoom in very far. These superzoom cameras are suitable for people who have nearsightedness.

    The HX series is a series containing Sony’s superzoom cameras like HX20VHX90V and the newest HX99. HX stands for HyperXoom.

    Light-field camera

    [edit]

    This type of digital camera captures information about the light field emanating from a scene; that is, the intensity of light in a scene, and also the direction that the light rays are traveling in space. This contrasts with a conventional digital camera, which records only light intensity.

    Event camera

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    Instead of measuring the intensity of light over some predetermined time interval (the exposure time), event cameras detect when the intensity of light changes by some threshold for each pixel independently, usually with microsecond precision.

    Integration into other devices

    [edit]

    Many devices have a built-in digital camera, including, for example, smartphones, mobile phones, PDAs and laptop computers. Built-in cameras generally store the images in the JPEG file format, although cameras in Apple’s iPhone line have used the HEIC format since 2017.[68]

    Mobile phones incorporating digital cameras were introduced in Japan in 2001 by J-Phone. In 2003 camera phones outsold stand-alone digital cameras, and in 2006 they outsold film and digital stand-alone cameras. Five billion camera phones were sold in five years, and by 2007 more than half of the installed base of all mobile phones were camera phones. Sales of separate cameras peaked in 2008.[69]

    Notable digital camera manufacturers

    [edit]

    Main article: List of digital camera brands

    There are many manufacturers that lead in the production of digital cameras (commonly DSLRs). Each brand embodies different mission statements that differ them from each other outside of the physical technology that they produce. While the majority of manufacturers share modern features amongst their production of cameras, some specialize in specific details either physically on camera or within the system and image quality.

    A Nikon D200 camera with a Nikon 17-55 mm / 2,8 G AF-S DX IF-ED lens and a Nikon SB-800 flash. Flashes are used as attachment to a camera to provide light to the image, timed with the shutter of the camera.
    Canon EF 70-200 f/2.8 lens mounted on a Canon 7D camera body. Lenses of varying lengths can be equipped onto main camera bodies to provide different perspectives for an image taken.

    [edit]

    Chart of sale of smartphones (with built-in cameras) compared to digital cameras 2009–2013 showing smartphone sale soaring while camera sale is stagnating
    Sale of smartphones compared to digital cameras 2009–2013

    Sales of traditional digital cameras have declined due to the increasing use of smartphones for casual photography, which also enable easier manipulation and sharing of photos through the use of apps and web-based services. “Bridge cameras”, in contrast, have held their ground with functionality that most smartphone cameras lack, such as optical zoom and other advanced features.[70][71] DSLRs have also lost ground to Mirrorless interchangeable-lens camera (MILC)s offering the same sensor size in a smaller camera. A few expensive ones use a full-frame sensor, just like DSLR professional cameras.

    In response to the convenience and flexibility of smartphone cameras, some manufacturers produced “smart” digital cameras that combine features of traditional cameras with those of a smartphone. In 2012, Nikon and Samsung released the Coolpix S800c and Galaxy Camera, the first two digital cameras to run the Android operating system. Since this software platform is used in many smartphones, they can integrate with some of the same services (such as e-mail attachmentssocial networks and photo sharing sites) that smartphones do and use other Android-compatible software.[70]

    In an inversion, some phone makers have introduced smartphones with cameras designed to resemble traditional digital cameras. Nokia released the 808 PureView and Lumia 1020 in 2012 and 2013; the two devices respectively run the Symbian and Windows Phone operating systems, and both include a 41-megapixel camera (along with a camera grip attachment for the latter).[72] Similarly, Samsung introduced the Galaxy S4 Zoom, having a 16-megapixel camera and 10x optical zoom, combining traits from the Galaxy S4 Mini with the Galaxy Camera.[73] Panasonic Lumix DMC-CM1 is an Android KitKat 4.4 smartphone with 20MP, 1″ sensor, the largest sensor for a smartphone ever, with Leica fixed lens equivalent of 28 mm at F2.8, can take RAW image and 4K video, has 21 mm thickness.[74] Furthermore, in 2018 Huawei P20 Pro is an android Oreo 8.1 has triple Leica lenses in the back of the smartphone with 40MP 1/1.7″ RGB sensor as first lens, 20MP 1/2.7″ monochrome sensor as second lens and 8MP 1/4″ RGB sensor with 3x optical zoom as third lens.[75] Combination of first lens and second lens will produce bokeh image with larger high dynamic range, whereas combination of mega pixel first lens and optical zoom will produce maximum 5x digital zoom without loss of quality by reducing the image size to 8MP.[76]

    After a big dip of sales in 2012, consumer digital camera sales declined again in 2013 by 36 percent. In 2011, compact digital cameras sold 10 million per month. In 2013, sales fell to about 4 million per month. DSLR and MILC sales also declined in 2013 by 10–15% after almost ten years of double digit growth.[77] Worldwide unit sales of digital cameras is continuously declining from 148 million in 2011 to 58 million in 2015 and tends to decrease more in the following years.[78]

    Film camera sales hit their peak at about 37 million units in 1997, while digital camera sales began in 1989. By 2008, the film camera market had died and digital camera sales hit their peak at 121 million units in 2010. In 2002, cell phones with an integrated camera had been introduced and in 2003 the cell phone with an integrated camera had sold 80 million units per year. By 2011, cell phones with an integrated camera were selling hundreds of millions per year, which were causing a decline in digital cameras. In 2015, digital camera sales were 35 million units or only less than a third of digital camera sales numbers at their peak and also slightly less than film camera sold number at their peak.[citation needed]

    Connectivity

    [edit]

    Transferring photos

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    Many digital cameras can connect directly to a computer to transfer data:-

    • Early cameras used the PC serial portUSB is now the most widely used method (most cameras are viewable as USB mass storage), though some have a FireWire port. Some cameras use USB PTP mode for connection instead of USB MSC; some offer both modes.
    • Cameras with integrated Wi-Fi or specific Wi-Fi adapters mostly allow camera control, especially shutter release, exposure control and more (tethering) from computer or smartphone apps additionally to the transfer of media data.
    • Cameraphones and some high-end stand-alone digital cameras also use cellular networks to connect for sharing images. The most common standard on cellular networks is the MMS Multimedia Messaging Service, commonly called “picture messaging”. The second method with smartphones is to send a picture as an email attachment. Many old cameraphones, however, do not support email.

    A common alternative is the use of a card reader which may be capable of reading several types of storage media, as well as high speed transfer of data to the computer. Use of a card reader also avoids draining the camera battery during the download process. An external card reader allows convenient direct access to the images on a collection of storage media. But if only one storage card is in use, moving it back and forth between the camera and the reader can be inconvenient. Many computers have a card reader built in, at least for SD cards.

    Printing photos

    [edit]

    Many modern cameras support the PictBridge standard, which allows them to send data directly to a PictBridge-capable printer without the need for a computer. PictBridge uses PTP to transfer images and control information.

    Wireless connectivity can also provide for printing photos without a cable connection.

    An instant-print camera, is a digital camera with a built-in printer.[79] This confers a similar functionality as an instant camera which uses instant film to quickly generate a physical photograph. Such non-digital cameras were popularized by Polaroid with the SX-70 in 1972.[80]

    Displaying photos

    [edit]

    Many digital cameras include a video output port. Usually sVideo, it sends a standard-definition video signal to a television, allowing the user to show one picture at a time. Buttons or menus on the camera allow the user to select the photo, advance from one to another, or automatically send a “slide show” to the TV.

    HDMI has been adopted by many high-end digital camera makers, to show photos in their high-resolution quality on an HDTV.

    In January 2008, Silicon Image announced a new technology for sending video from mobile devices to a television in digital form. MHL sends pictures as a video stream, up to 1080p resolution, and is compatible with HDMI.[81]

    Some DVD recorders and television sets can read memory cards used in cameras; alternatively several types of flash card readers have TV output capability.

    Weather-sealing and waterproofing

    [edit]

    Cameras can be equipped with a varying amount of environmental sealing to provide protection against splashing water, moisture (humidity and fog), dust and sand, or complete waterproofness to a certain depth and for a certain duration. The latter is one of the approaches to allow underwater photography, the other approach being the use of waterproof housings. Many waterproof digital cameras are also shockproof and resistant to low temperatures.

    Some waterproof cameras can be fitted with a waterproof housing to increase the operational depth range. The Olympus ‘Tough’ range of compact cameras is an example.

    Modes

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    Many digital cameras have preset modes for different applications. Within the constraints of correct exposure various parameters can be changed, including exposure, aperture, focusinglight meteringwhite balance, and equivalent sensitivity. For example, a portrait might use a wider aperture to render the background out of focus, and would seek out and focus on a human face rather than other image content.

    Few cameras are equipped with a voice note (audio-only) recording feature.[82]

    Scene modes

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    Vendors implement a variety scene modes in cameras’ firmwares for various purposes, such as a “landscape mode” which prevents focusing on rainy and/or stained window glass such as a windshield, and a “sports mode” which reduces motion blur of moving subjects by reducing exposure time with the help of increased light sensitivity. Firmwares may be equipped with the ability to select a suitable scene mode automatically through artificial intelligence.[83][84]

    Image data storage

    [edit]

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    CompactFlash (CF) card, one of many media types used to store digital photographs
    Digital camera (Panasonic Lumix DMC-TZ10) user interface, indicating the approximate count of remaining photos.

    Many camera phones and most stand alone digital cameras store image data in flash memory cards or other removable media. Most stand-alone cameras use SD format, while a few use CompactFlash, CFexpress or other types. In January 2012, a faster XQD card format was announced.[85] In early 2014, some high end cameras have two hot-swappable memory slots. Photographers can swap one of the memory card with camera-on. Each memory slot can accept either Compact Flash or SD Card. All new Sony cameras also have two memory slots, one for its Memory Stick and one for SD Card, but not hot-swapable.[86]

    The approximate count of remaining photos until space exhaustion is calculated by the firmware throughout use and indicated in the viewfinder, to prepare the user for an impending necessary hot swap of the memory card, and/or file offload.

    A few cameras used other removable storage such as Microdrives (very small hard disk drives), CD single (185 MB),[87] and 3.5″ floppy disks (e. g. Sony Mavica). Other unusual formats include:

    • Onboard (internal) flash memory — Cheap cameras and cameras secondary to the device’s main use (such as a camera phone). Some have small capacities such as 100 Megabytes and less, where intended use is buffer storage for uninterrupted operation during a memory card hot swap.[88]
    • SuperDisk (LS120) used in two Panasonic digital cameras, the PV-SD4090[89] and PV-SD5000,[90] which allowed them to use both SuperDisk and 3.5″ floppy disks
    • PC Card hard drives — early professional cameras (discontinued)[91]
    • PC Card flash memory cards[92]
    • Thermal printer — known only in the Casio Petit Colle ZR-1 and ZR-10[93][94] which printed images immediately rather than storing
    • Zink technology — printing images immediately rather than storing
    • PocketZip — media used in the Agfa ePhoto CL30 Clik!

    Most manufacturers of digital cameras do not provide drivers and software to allow their cameras to work with Linux or other free software.[clarification needed] Still, many cameras use the standard USB mass storage and/or Media Transfer Protocol, and are thus widely supported. Other cameras are supported by the gPhoto project, and many computers are equipped with a memory card reader.

    File formats

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    Main article: Image file formats

    The Joint Photography Experts Group standard (JPEG) is the most common file format for storing image data. Other file types include Tagged Image File Format (TIFF) and various Raw image formats.

    Many cameras, especially high-end ones, support a raw image format. A raw image is the unprocessed set of pixel data directly from the camera’s sensor, often saved in a proprietary formatAdobe Systems has released the DNG format, a royalty-free raw image format used by at least 10 camera manufacturers.

    Raw files initially had to be processed in specialized image editing programs, but over time many mainstream editing programs, such as Google’s Picasa, have added support for raw images. Rendering to standard images from raw sensor data allows more flexibility in making major adjustments without losing image quality or retaking the picture.

    Formats for movies are AVIDV, MPEG, MOV (often containing motion JPEG), WMV, and ASF (basically the same as WMV). Recent formats include MP4, which is based on the QuickTime format and uses newer compression algorithms to allow longer recording times in the same space.

    Other formats that are used in cameras (but not for pictures) are the Design Rule for Camera Format (DCF), an ISO specification, used in almost all camera since 1998, which defines an internal file structure and naming. Also used is the Digital Print Order Format (DPOF), which dictates what order images are to be printed in and how many copies. The DCF 1998 defines a logical file system with 8.3 filenames and makes the usage of either FAT12, FAT16, FAT32 or exFAT mandatory for its physical layer in order to maximize platform interoperability.[95]

    Most cameras include Exif data that provides metadata about the picture. Exif data may include aperture, exposure time, focal length, date and time taken. Some are able to tag the location.

    Directory and file structure

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    Main article: Design rule for Camera File system

    In order to guarantee interoperability, DCF specifies the file system for image and sound files to be used on formatted DCF media (like removable or non-removable memory) as FAT12FAT16FAT32, or exFAT.[96] Media with a capacity of more than 2 GB must be formatted using FAT32 or exFAT.

    The filesystem in a digital camera contains a DCIM (Digital Camera IMagesdirectory, which can contain multiple subdirectories with names such as “123ABCDE” that consist of a unique directory number (in the range 100…999) and five alphanumeric characters, which may be freely chosen and often refer to a camera maker. These directories contain files with names such as “ABCD1234.JPG” that consist of four alphanumeric characters (often “100_”, “DSC0”, “DSCF”, “IMG_”, “MOV_”, or “P000”), followed by a number. Handling of directories with possibly user-created duplicate numbers may vary among camera firmwares.

    DCF 2.0 adds support for DCF optional files recorded in an optional color space (that is, Adobe RGB rather than sRGB). Such files must be indicated by a leading “_” (as in “_DSC” instead of “100_” or “DSC0”).[96]

    Thumbnail files

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    To enable loading many images in miniature view quickly and efficiently, and to retain meta data, some vendors’ firmwares generate accompanying low-resolution thumbnail files for videos and raw photos. For example, those of Canon cameras end with .THM.[97] JPEG can already store a thumbnail image standalone.[98]

    Batteries

    [edit]

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    Digital cameras have become smaller over time, resulting in an ongoing need to develop a battery small enough to fit in the camera and yet able to power it for a reasonable length of time.[citation needed]

    Digital cameras utilize either proprietary or standard consumer batteries. As of March 2014, most cameras use proprietary lithium-ion batteries while some use standard AA batteries or primarily use a proprietary Lithium-ion rechargeable battery pack but have an optional AA battery holder available.

    Proprietary

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    The most common class of battery used in digital cameras is proprietary battery formats. These are built to a manufacturer’s custom specifications. Almost all proprietary batteries are lithium-ion. In addition to being available from the OEM, aftermarket replacement batteries are commonly available for most camera models.

    Standard consumer batteries

    [edit]

    Main article: Commercial off-the-shelf

    Digital cameras that utilize off-the-shelf batteries are typically designed to be able to use both single-use disposable and rechargeable batteries, but not with both types in use at the same time. The most common off-the-shelf battery size used is AA. CR2, CR-V3 batteries, and AAA batteries are also used in some cameras. The CR2 and CR-V3 batteries are lithium based, intended for a single use. Rechargeable RCR-V3 lithium-ion batteries are also available as an alternative to non-rechargeable CR-V3 batteries.

    Some battery grips for DSLRs come with a separate holder to accommodate AA cells as an external power source.

    Conversion of film cameras to digital

    [edit]

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    Digital single-lens reflex camera

    When digital cameras became common, many photographers asked whether their film cameras could be converted to digital. The answer was not immediately clear, as it differed among models. For the majority of 35 mm film cameras the answer is no, the reworking and cost would be too great, especially as lenses have been evolving as well as cameras. For most a conversion to digital, to give enough space for the electronics and allow a liquid crystal display to preview, would require removing the back of the camera and replacing it with a custom built digital unit.

    Many early professional SLR cameras, such as the Kodak DCS series, were developed from 35 mm film cameras. The technology of the time, however, meant that rather than being digital “backs” the bodies of these cameras were mounted on large, bulky digital units, often bigger than the camera portion itself. These were factory built cameras, however, not aftermarket conversions.

    A notable exception is the Nikon E2 and Nikon E3, using additional optics to convert the 35 mm format to a 2/3 CCD-sensor.

    A few 35 mm cameras have had digital camera backs made by their manufacturer, Leica being a notable example with the Leica R8–R9Medium format and large format cameras (those using film stock greater than 35 mm), have a low unit production, and typical digital backs for them cost over $10,000. These cameras also tend to be highly modular, with handgrips, film backs, winders, and lenses available separately to fit various needs.

    The very large sensor these backs use leads to enormous image sizes. For example, Phase One’s P45 39 MP image back creates a single TIFF image of size up to 224.6 MB, and even greater pixel counts are available. Medium format digitals such as this are geared more towards studio and portrait photography than their smaller DSLR counterparts; the ISO speed in particular tends to have a maximum of 400, versus 6400 for some DSLR cameras. (Canon EOS-1D Mark IV and Nikon D3S have ISO 12800 plus Hi-3 ISO 102400 with the Canon EOS-1Dx’s ISO of 204800).

    Digital camera backs

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    Main article: Digital camera back

    In the industrial and high-end professional photography market, some camera systems use modular (removable) image sensors. For example, some medium format SLR cameras, such as the Mamiya 645D series, allow installation of either a digital camera back or a traditional photographic film back.

    • Area array
      • CCD
      • CMOS
    • Linear array
      • CCD (monochrome)
      • 3-strip CCD with color filters

    Linear array cameras are also called scan backs.

    • Single-shot
    • Multi-shot (three-shot, usually)

    Most earlier digital camera backs used linear array sensors, moving vertically to digitize the image. Many of them only capture grayscale images. The relatively long exposure times, in the range of seconds or even minutes generally limit scan backs to studio applications, where all aspects of the photographic scene are under the photographer’s control.

    Some other camera backs use CCD arrays similar to typical cameras. These are called single-shot backs.

    Since it is much easier to manufacture a high-quality linear CCD array with only thousands of pixels than a CCD matrix with millions, very high resolution linear CCD camera backs were available much earlier than their CCD matrix counterparts. For example, you could buy an (albeit expensive) camera back with over 7,000 pixel horizontal resolution in the mid-1990s. However, as of 2004, it is still difficult to buy a comparable CCD matrix camera of the same resolution. Rotating line cameras, with about 10,000 color pixels in its sensor line, are able, as of 2005, to capture about 120,000 lines during one full 360 degree rotation, thereby creating a single digital image of 1,200 Megapixels.

    Most modern digital camera backs use CCD or CMOS matrix sensors. The matrix sensor captures the entire image frame at once, instead of incrementing scanning the frame area through the prolonged exposure. For example, Phase One produces a 39 million pixel digital camera back with a 49.1 x 36.8 mm CCD in 2008. This CCD array is a little smaller than a frame of 120 film and much larger than a 35 mm frame (36 x 24 mm). In comparison, consumer digital cameras use arrays ranging from 36 x 24 mm (full frame on high end consumer DSLRs) to 1.28 x 0.96 mm (on camera phones) CMOS sensor.