Saturday, February 11, 2012

Overview

Camcorders accommodate three aloft components: lens, imager, and recorder. The lens gathers and focuses ablaze on the imager. The imager (usually a CCD or CMOS sensor on avant-garde camcorders; advanced examples about acclimated vidicon tubes) converts adventure ablaze into an electrical signal. Finally, the recorder converts the electric arresting into video and encodes it into a storable form. Added commonly, the eyes and imager are referred to as the camera section.

edit Lens

The lens is the aboriginal basal in the ablaze path. The camcorder's eyes about accept one or added of the afterward adjustments:

breach or iris to adapt the acknowledgment and to ascendancy abyss of field;

zoom to ascendancy the focal breadth and bend of view;

bang acceleration to adapt the acknowledgment and to beforehand adapted motion portrayal;

accretion to amplify arresting backbone in low-light conditions;

aloof body clarify to adapt the exposure.

In customer units, the aloft adjustments are about automatically controlled by the camcorder's electronics, but can be adapted manually if desired. Able units action absolute user ascendancy of all aloft optical functions.

edit Imager

The imager converts ablaze into electric signal. The camera lens projects an angel assimilate the imager surface, advertisement the photosensitive adjustment to light. The ablaze acknowledgment is adapted into electrical charge. At the end of the timed exposure, the imager converts the accumulated allegation into a connected analog voltage at the imager's achievement terminals. Afterwards scan-out is complete, the photosites are displace to alpha the exposure-process for the next video frame.

edit Recorder

The recorder is amenable for autograph the video-signal assimilate a recording average (such as alluring videotape.) The almanac action involves abounding signal-processing steps, and historically, the recording-process alien some baloney and babble into the stored video, such that playback of the stored-signal may not absorb the aforementioned characteristics/detail as the reside video feed.

All but the a lot of archaic camcorders apprehensible aswell allegation to accept a recorder-controlling area which allows the user to ascendancy the camcorder, about-face the recorder into playback approach for reviewing the recorded footage and an angel ascendancy area which controls exposure, focus and white-balance.

The angel recorded allegation not be bound to what appeared in the viewfinder. For affidavit of events, such as acclimated by police, the acreage of appearance overlays such things as the time and date of the recording forth the top and basal of the image. Such things as the badge car or constable to which the recorder has been allotted may aswell appear; aswell the acceleration of the car at the time of recording. Compass administration at time of recording and bounded coordinates may aswell be possible. These are not kept to world-standard fields; "month/day/year" may be seen, as able-bodied as "day/month/year", besides the ISO accepted "year-month-day".

edit Customer camcorders

edit Analog vs. digital

Camcorders are about classified by their accumulator device: VHS, VHS-C, Betamax, Video8 are examples of 20th aeon videotape-based camcorders which almanac video in analog form. Newer agenda video camcorder formats awning Digital8, MiniDV, DVD, Harder deejay drive absolute to deejay recording and solid-state semiconductor Beam anamnesis memory. While all these formats almanac video in agenda form, currently formats like Digital8, MiniDV and DVD accept been accident favor, and are no best acclimated in the a lot of contempo customer camcorders.

In earlier analog camcorders, the imaging accessory was based on exhaustion tube technology area the allegation on a ablaze acute ambition was in absolute admeasurement to the bulk of ablaze arresting it. A accepted archetype of such an imaging tube was the Vidicon. Newer analog and all agenda camcorders use a solid accompaniment Allegation Coupled Accessory (CCD) imaging device, or added afresh a CMOS imager. Both of these closing accessories use photodiodes that canyon a accepted proportional to the ablaze arresting them (i.e. they are analog detectors), but that accepted is afresh digitised afore getting electronically 'scanned' afore getting fed to the imager's output. The arch aberration in the closing two accessories is in the address in which that 'scanning' is accomplished. In the CCD, the diodes are all sampled simultaneously, and the scanning afresh accomplished by accidental the digitised abstracts from one annals to the next (the Allegation Coupled element). In the CMOS accessory the diodes are sampled anon by the scanning logic.

The yield up of agenda video accumulator bigger quality. MiniDV accumulator allows abounding resolution video (720x576 for PAL, 720x480 for NTSC), clashing antecedent alternation customer video standards. Agenda video does not acquaintance colour bleeding, jitter, or fade, although some users still adopt the analog attributes of Hi8 and Super VHS-C, aback neither of these aftermath the "background blur" or "mosquito noise" of agenda video compression. In abounding cases, a high-quality analog recording shows added detail (such as asperous textures on a wall) than a aeroembolism agenda recording (which would appearance the aforementioned bank as collapsed and featureless).

Unlike analog video formats, the agenda video formats do not ache bearing accident during dubbing, but can be added decumbent to complete loss. Theoretically agenda advice can be stored indefinitely with aught abasement on a agenda accumulator accessory (such as a harder drive), about aback some agenda formats (like MiniDV) about clasp beforehand alone ~10 micrometers afar (versus 19 to 58 μm for VHS), a agenda recording is added accessible to wrinkles or stretches in the band that could assuredly abolish several scenes account of agenda data, but the additions tracking and absurdity alteration cipher on the band will about atone for a lot of defects. On analog media agnate accident about registers as "noise" in the video, still abrogation a attenuated but watchable video. The alone limitation is that this video has to be played on a absolutely alternation examination system, contrarily the band will not affectation any video due to the accident and accompany problems. Even agenda recordings on DVD are accepted to ache from DVD rot that assuredly abolish huge chunks of data. Thus the one advantage analog seems to accept in this account is that an analog recording may be "usable" even afterwards the media it is stored on has suffered astringent abasement admitting it has been noticed9 that even slight media abasement in agenda recordings may could could cause them to ache from an "all or nothing" failure, i.e. the agenda recording will end up getting absolutely un-playable after actual big-ticket apology work.

edit Avant-garde recording media

For added information, see tapeless camcorder.

While some earlier agenda camcorders almanac video on Microdrives and size-reduced DVD-RAM or DVD-Rs, as of 2011 a lot of contempo camcorders almanac video on beam anamnesis accessories and baby harder disks, application MPEG-1, MPEG-2 or MPEG-4 formats. However, because these codecs use inter-frame compression, frame-specific-editing requires anatomy regeneration, which incurs added processing and can could could cause accident of account information. (In able usage, it is accepted to use a codec that will abundance every anatomy individually. This provides easier and faster frame-specific alteration of scenes.)

Other agenda customer camcorders almanac in DV or HDV architecture on band and alteration agreeable over FireWire (some aswell use USB 2.0) to a computer, area the huge files (for DV, 1GB for 4 to 4.6 account in PAL/NTSC resolutions) can be edited, converted, and (with abounding camcorders) aswell recorded aback to tape. The alteration is done in absolute time, so the complete alteration of a 60 minute band needs one hour to alteration and about 13GB deejay amplitude for the raw footage only—excluding any amplitude bare for cede files, and added media. Time spent in post-production (editing) to baddest and cut the best shots varies from direct "magic" movies to hours of annoying selection, adjustment and rendering.

edit Customer market

As the accumulation customer bazaar favors affluence of use, portability, and price, a lot of of the consumer-grade camcorders awash today accent administration and automation appearance over raw audio/video performance. Thus, the majority of accessories able of action as camcorders are camera phones or bunched agenda cameras, for which video is alone a affection or a accessory capability.

Even for abstracted accessories advised primarily for motion video, this articulation has followed an evolutionary aisle apprenticed by adamant miniaturization and amount reduction, fabricated accessible by beforehand in architecture and manufacturing. Miniaturization conflicts with the imager's adeptness to accumulate light, and designers accept cautiously counterbalanced improvements in sensor acuteness with sensor admeasurement reduction, shrinking the all-embracing camera imager & optics, while advancement analytic noise-free video in ample daylight. Indoor or dim ablaze cutting is about unacceptably noisy, and in such conditions, bogus lighting is awful recommended. Mechanical controls cannot calibration beneath a assertive size, and chiral camera operation has accustomed way to camera-controlled automation for every cutting constant (focus, aperture, bang speed, white balance, etc.). The few models that do absorb chiral override frequently crave the user to cross a bulky agenda interface. Outputs awning USB 2.0, Composite and S-Video, and IEEE 1394/Firewire (for MiniDV models). On the added side, today's camcorders are affordable to a added articulation of the customer market, and accessible in a added array of anatomy factors and functionality, from the archetypal camcorder shape, to baby flip-cameras, to video-capable camera-phones and "digicams."

At the high-end of the customer market, there is a greater accent on user ascendancy and avant-garde cutting modes. Feature-wise, there is some overlap amid the high-end customer and "prosumer" markets. Added big-ticket customer camcorders about action chiral acknowledgment control, HDMI achievement and alien audio input, progressive-scan framerates (24fps, 25fps, 30fps), and bigger lenses than basal models. In adjustment to aerate low-light capability, blush reproduction, and anatomy resolution, a few manufacturers action multi-CCD/CMOS camcorders, which actor the 3-element imager architecture acclimated in able equipment. Acreage tests accept approved a lot of customer camcorders (regardless of price), to aftermath blatant video in low light.

Before the 21st century, video alteration was a difficult assignment acute a minimum of two recorders and possibly a desktop video workstation to ascendancy them. Now, the archetypal home claimed computer can authority several hours of standard-definition video, and is fast abundant to adapt footage after added upgrades. A lot of customer camcorders are awash with basal video alteration software, so users can calmly actualize their own DVDs, or allotment their edited footage online.

JVC GZ-MG555 amalgam camcorder (MPEG-2 SD Video)

In the aboriginal apple market, about all camcorders awash today are digital. Tape-based (MiniDV/HDV) camcorders are no best popular, aback tapeless models (SD agenda & centralized drive) amount about the same, but action abundant greater convenience. For example, video captured on SD agenda can be transferred to a computer abundant faster than from agenda tape. Harder deejay camcorders affection the longest connected recording time, admitting the backbone of the harder drive is a affair for acrid and high-altitude environments. As of 2012, none of the new consumer-class camcorders arise at the 2011 International Customer Electronics Appearance almanac on tape.6 However, in some locations of the world, newly-manufactured band camcorders ability still be accessible due to the lower purchasing ability or greater amount acuteness of the consumers in these areas.

edit Added accessories with video-capture capability

Video-capture adequacy is not bedfast to camcorders. Cellphones, agenda individual lens reflex and bunched digicams, laptops, and claimed media players frequently action some anatomy of video-capture capability. In general, these multipurpose-devices action beneath functionality for video-capture, than a acceptable camcorder. A lot of abridgement chiral adjustments, external-audio input, and even basal account functions such as autofocus and lens-zoom. Few can abduction to accepted TV-video formats (480p60, 720p60, 1080i30), and instead almanac in either non-TV resolutions (320x240, 640x480, etc.) or slower frame-rates (15fps, 30fps.)

When acclimated in the role of a camcorder, a multipurpose-device tends to action inferior administration and audio/video performance, which banned its account for connected and/or adverse cutting situations. However, abundant as camera-equipped cellphones are now ubiquitous, video-equipped cyberbanking accessories will acceptable become commonplace, replacing the bazaar for low-end camcorders.

DSLR cameras with high-definition video were alien aboriginal in the 21st century. Although they still ache from the archetypal administration and account deficiencies of added multipurpose-devices, HDSLR video offers bank depth-of-field and changeable lenses which customer camcorders lack. Able video cameras possessing these capabilities are currently added big-ticket than even the a lot of big-ticket video-capable DSLR. In video applications area the DSLR's operational deficiencies can be mitigated by accurate planning, a growing amount of video productions are employing DSLRs, such as the Canon 5D Mark II, to accomplish the admiration for depth-of-field and optical-perspective control. Whether in a flat or on-location setup, the scene's ecology factors and camera adjustment are accepted beforehand, acceptance the administrator of photography to actuate the able camera/lens bureaucracy and administer any all-important ecology adjustments, such as lighting.

Combo-cameras amalgamate the feature-sets of full-feature still-camera and camcorder in a individual unit. The Sanyo Xacti HD1 was the aboriginal such admixture unit, accumulation the appearance of a 5.1 megapixel still-camera with a 720p video recorder. Overall, the artefact was a footfall advanced in agreement of a single-device's accumulated akin of administration and usability. The admixture camera's abstraction has bent on with aggressive manufacturers; Canon and Sony accept alien camcorders with still-photo achievement abutting a acceptable digicam, while Panasonic has alien a DSLR-body with video appearance abutting a acceptable camcorder. Hitachi accept alien the DZHV 584E/EW which has 1080p resolution. This archetypal comes with a 3" pop-up blow screen, housed in a slimline case and about the admeasurement of a adaptable phone.

edit Changeable lens camcorder

As about-face of DSLR cameras with high-definition video, in 2011 at atomic there are 2 Changeable lens camcorders which can abduction Abounding HD video with abounding ascendancy of camcorder, Panasonic AG-AF100 and Sony NEX-VG10 both with big sensor, not as accepted as non-professional camcorders. The DSLR lenses can be acclimated with adapter for versatilities.10

edit Camcorder with congenital projector

In 2011 Sony arise the HDR-PJ10/30/50 HD camcorders, the aboriginal camcorders in the apple to absorb a baby angel projector on the ancillary of the unit. This affection allows assuming videos to a accumulation of admirers after application a television, a full-size projector, or a computer.11 The Specification varies amid anniversary model, the HDR-PJ10 is the abject archetypal with 16GB centralized beam anamnesis with the advantage to add a anamnesis agenda of up to 64GB giving a abstract accommodation of 80GB. The HDR-PJ30 is the mid ambit archetypal with 32GB centralized anamnesis (with the advantage to add a anamnesis agenda of up to 64GB giving a abstract accommodation of 96GB) and an added ablaze to aid in dim conditions. The HDR-PJ50 is the top of the ambit archetypal with a 220GB harder deejay drive and the added ablaze to aid in dim conditions. Additionally the HDR-PJ30 and 50 aswell almanac in 25p approach which provides an atmosphere afterpiece to that of film. A microphone jack is provided as accepted on all models. Agnate articles are accessible from ViewSonic12 and 3M.

edit 3D Camcorder

In 2011 Panasonic arise the world's aboriginal camcorder able of cutting in 3D, the HDC-SDT750. It is a approved 2D camcorder that can shoot in abounding HD while 3D is accomplished by the advertisement about-face lens. Sony after arise its own 3D camcorder, the HDR-TD10. Clashing the Panasonic, the Sony HDR-TD10 has the 3D lens congenital in but it can still shoot a accustomed 2D video. The down ancillary to this is that it after-effects in a rather beastly architecture and a top amount tag (£1,005.70 for the Sony vs. £686 for the Panasonic on Amazon). Panasonic accept aswell arise accustomed 2D camcorders with alternative 3D recording with the about-face lens getting an alternative extra. The HDC-SD90, HDC-SD900, HDC-TM900 and HDC-HS900 are marketed as '3D ready' getting affordable approved 2D camcorders with the advantage to add the 3D adequacy at a after date.

Sony, Fujifilm, Aiptek, Vivitar and some added manufacturers accept even marketed 3D abridged camcorders, an archetype getting the Sony MHS-FS3. JVC afresh arise its own 3D camcorder, the GS-TD1. Like the Sony HDR-TD10, it has the 3D lens congenital in and already afresh after-effects in a rather beastly architecture and a top amount tag £1,299.99 on Amazon. Sony accept arise the DEV-5 agenda recording binoculars. It's a 3D camcorder but in the anatomy of binoculars. The down ancillary of this abnormal camcorder is the ample amount tag, £2,605 on Sony's website, that's bifold the amount of the JVC GS-TD1. Currently Panasonic, Sony and JVC are the alone boilerplate manufacturers that accomplish 3D camcorders admitting several abate manufacturers aswell bazaar abridged camcorders but these are about alone accessible online, not in retail outlets. It is alien if any added manufacturers will bazaar their own 3D camcorders, alone time will tell.

edit Uses

edit Media

Operating a camcorder

Camcorders accept begin use in about all corners of cyberbanking media, from cyberbanking account organizations to TV/current-affairs productions. In locations abroad from a administration infrastructure, camcorders are invaluable for antecedent video acquisition. Subsequently, the video is transmitted electronically to a studio/production centermost for broadcast. Scheduled contest such as official columnist conferences, area a video basement is readily accessible or can be conceivably deployed in advance, are still covered by studio-type video cameras (tethered to "production trucks.")

edit Home video

For accidental use, camcorders about awning weddings, birthdays, graduation ceremonies, accouchement growing up, and added claimed events. The acceleration of the customer camcorder in the mid to backward '80s led to the conception of shows such as the long-running America's Funniest Home Videos, area humans could advertise bootleg video footage.

edit Politics

Political protestors who accept capitalized on the amount of media advantage use camcorders to blur things they accept to be unjust. Beastly rights protesters who breach into branch farms and beastly testing labs use camcorders to blur the altitude the animals are active in. Anti-hunting protesters blur fox hunts. Humans assured to attestant political crimes use cameras for surveillance to aggregate evidence. Activist videos about arise on Indymedia.

The badge use camcorders to blur riots, protests and the crowds at antic events. The blur can be acclimated to atom and aces out troublemakers, who can afresh be prosecuted in court. In countries such as the United States, the use of bunched dashboard camcorders in badge cars allows the badge to absorb a almanac of any action that takes abode in foreground of the car, such as alternation with a motorist chock-full on the highway.

edit Entertainment and movies

Camcorders are about acclimated in the assembly of low-budget TV shows area the assembly aggregation does not accept admission to added big-ticket equipment. There are even examples of movies attempt absolutely on customer camcorder accessories (such as The Blair Witch Project and 28 Days Later). In addition, abounding bookish filmmaking programs accept switched from 16mm blur to agenda video, due to the awfully bargain amount and affluence of alteration of the agenda average as able-bodied as the accretion absence of blur banal and equipment. Some camcorder manufacturers baby to this market, decidedly Canon and Panasonic, who both abutment "24p" (24 frame/s, accelerating scan; aforementioned anatomy amount as accepted cinema film) video in some of their high-end models for simple blur conversion.

Even high-budget cinema is done application camcorders in some cases; George Lucas acclimated Sony CineAlta camcorders in two of his three Star Wars prequel movies. This action is referred to as agenda cinematography.

edit Education, Abecedary Appraisal and Abecedary Preparation

Secondary Apprenticeship and Higher Apprenticeship in the developed apple is added amalgam agenda media and accretion into the bolt of acceptance acquirements experiences. Acceptance about use camcorders to almanac video diaries, accomplish abbreviate films, and advance a array of multi-media projects beyond accountable disciplines.

Meanwhile abecedary appraisal added involves teacher's classroom acquaint getting digitally recorded for analysis by academy administrators and academy commune officials. This is abnormally accepted during the action of tenure-granting (or withholding), and in cases area teacher's connected administration may be in question. Some feel the use of agenda recording allows both academy districts and teacher's unions an befalling to added considerately and assiduously analysis aspects of abecedary achievement in the classroom setting, whilst others, such as Alfie Kohn are far added skeptical.

Recently in abounding a top ranked Academy of Education, affiliation of apprentice camcorder-created actual as able-bodied as added agenda technology has built-in itself into the bolt of new abecedary alertness courses. The University of Oxford Department of Apprenticeship PGCE programme and NYU's Steinhardt School's Department of Teaching and Acquirements MAT programme accommodate two examples of this trend.

The USC Rossier Academy of Apprenticeship takes this one footfall further, by insisting that all acceptance acquirement their own camcorder (or agnate agenda video recording devise) as a prerequisite to alpha their MAT apprenticeship programmes, abounding of which are delivered absolutely online. These programmes apply a adapted adaptation of Adobe Connect to bear the absolute accomplished basal of the MAT@USC. MAT acceptance in-class teaching is captured by camcorder, acquaint to USC's web portal, and afresh go through a action of appraisal by adroitness in a agnate address to what they would use if they were physically present in class.

In this way the use of the camcorder has accustomed USC to absolutely de-centralize its abecedary alertness abroad from Southern California to a lot of American states, and several countries about the world; and this has abundantly added the amount of agents they are able to alternation at once. With cogent abecedary shortages looming in the USA, UK, Canada and Australia over the next few years, this is acceptable to be a archetypal which added institutions seek to emulate.

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