Digital camera, full English name:Digital Still Camera(DSC), referred to as Digital Camera (DC), is the abbreviation of digital camera, also known as digital camera.Digital camera is a kind of electronic sensor that converts optical image intoelectronic data 's camera.
Digital camera is a product integrating optics, mechanics and electronics.It integrates the conversion, storage and transmission of image information and has the characteristics of digital access mode, interactive processing with computers and real-time shooting.Light passing through the lens orLens groupEnter the camera and convert it intodigital signalDigital signals are stored in thestorage deviceMedium.The imaging element of digital camera is CCD orCMOSThe imaging element is characterized by that when light passes through, it can be converted intoElectronic signal。Digital cameras first appeared in the United States. More than 20 years ago, the United States used them to transmit photos to the ground via satellite. Later, digital photography became civilian and expanded continuouslyScope of application。
Advantages and disadvantages
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advantage
1. After taking a picture, you can see the picture immediately, which provides the possibility of re shooting unsatisfied works immediately and reduces the occurrence of regret.
2. You only need to pay for the photos you want to develop. Other unnecessary photos can be deleted.
3、Color restorationAnd color range no longer depend on film quality.
The history of digital camera can be traced back to the 1940s and 1950s. In 1951, Bin Crosby Laboratory inventedvideo recorder(VTR), this new machine canCurrent pulseRecord on tape.By 1956, video recorders began mass production.It is regarded asElectronic imagingTechnology generation.
NASA in the 1960s（NASA）When astronauts are sent toMoonBefore that, NASA must survey the surface of the moon.However, engineers found thatanalog signalIt is mingled with other rays in the universe and appears very weakreceiverThe signal cannot be converted into a clear image.So the engineers had to find another way.After that, digital imagestechnological development Faster, mainly due toCold WarOf periodScience and technology competition。These technologies are also mainly used in the military fieldSpy satelliteAll use digital image technology.
It started in the 1960s“CCD chip”Ofresearch and developmentIn 1969,Bell LaboratoriesGeorge Smith and Willard Boyle ofVideophoneAnd semiconductor bubbleStorage technologyIn combination, the "Charge" Bubble "Devices" that can conduct charges along the semiconductor surface of the digital camera were designed, and the prototype of the CCD device was first invented.
At that time, CCD was invented to improve the storage technology, and the components themselves were also regarded as simplestorageuse.Then people realized that CCD could usephotoelectric effectTo capture and store images.
Birth background
In 1970, Bell Laboratories conducted relevant experiments.
CCD array is composed ofJet Propulsion LaboratoryIt was successfully developed in 1972, with a size of 100 * 100 pixels.Commercial CCD was also launched by Fairchild at the same time.At that time, the CCD gain was very low, only a fraction of a percentPhotographic negativeSlightly higher.
In 1975, in the United StatesNew YorkRochesterOfKodakIn the laboratory, a black and white image of a child and a dog isCCD sensorAcquired and recorded on the audio cassette tape.This is the first picture obtained by the world's first digital cameraDigital photosThe development of the imaging industry has changed.Thirty years later, the inventor behind the first digital camera came to China to review the history for us and use his keen insight to prospectDigital videoThe future of.
Steven Sasson
Steven Sasson joined Kodak after his master's degree in 1973 and became an engineer in the Applied Electronics Research Center.In 1974, he took charge of the invention of "handheldElectronic camera”The important task of.The next year, the first oneprototypeBorn in the laboratory, he also became the "father of digital cameras".
The purpose of this project is to shoot images without film. Its prototype product is only 10000 pixels, and the imaging is very rough.When it comes to that history, Saishang still remembers it vividly: "At that time, digital technology was very difficult, and CCD was difficult to control,A/D converterIt's hard to make, digitalstorage medium It is difficult to obtain, and the capacity is very small.There was no PC and playback equipmentrequirementCustomized.These difficulties took us one year to install this camera. "
The digital cameraKodakIt is a small project. Since we decided to adopt digital mode, there are not many moving machines in the camera. Saishang and two technical engineers completed this project.When selecting removable digital storage media, Saishang hopes thatStorage capacityIt can take about the same number of pictures as 35mm film, so the general card type is adopted finallytape, can basically store 30 photos equivalent to one film."Many technologies were very new at that time, and the circuit board of this prototype can be opened to shoot and adjust at the same time." Saishang seemed to return to the laboratory again.
"When the prototype was first shown to investors, they asked when this product could become a consumer product, and I replied that it would take 15 to 20 years for this product to enter ordinary consumer families." Saishang's judgment was quite accurate. The development of digital cameras was a long road, from the late 1970s to the early 1980s,Kodak Lab has produced more than 1000 patents related to digital cameras, laying the foundation for the architecture and development of digital cameras, and making digital cameras step by step into reality.In 1989, Kodak finally launched the first commercial digital camera.
development history
1、 Digital cameras in the 1990s
（1） Early products
1981SonyThe company invented the world's first non usePhotographic filmThe electronic still life camera of the "Maveka" still video camera.This is the prototype of today's digital camera.
In 1988, Fuji andToshibastayCologneAt the ExpoCo developmentFujixs digital still life camera "DS-1P" using flash memory card. Before and after that, Fujixs, Toshiba, OlympusKonica、CanonAnd published digital camera'sTrial products: such as Canon RC-701CASIOVS－101、Fuji DS-1P, Fuji DS-X, Toshiba MC2000, etc.
（2） Products in the early 1990s
In 1991, Kodak successfully trial produced the world's first digital camera,ToshibaThe MC-200 digital camera with 400000 pixels was released and sold for 1.7 million yen, which was the first digital camera sold in the market.
In 1994, Kodak commercial digital camera DC40 was officially launched.In February 1995, Casio released the low price digital camera QV-10 with 250000 pixels and 65000 yen, which triggered a boom in the digital camera market.1995Canon EOS·DCS3C was launched, and EOS · DCS1C was also launched in the same year, starting CanonDigital SLR cameraHistory of development.In 1995, the digital camera was officially opened.To welcome the arrival of digital cameras,KodakThe Board of Directors madeComprehensive developmentDecision making decision of digital science, in 1996Nikon Jointly launched the DCS － 460 and DCS － 620X digital cameras, and cooperated with Canon to launch the DCS － 420 digital camera (professional level).
In 1995, the number of digital camera pixels in the world was only 410000;By 1996, it had almost doubled to 810000 pixelsShipment 500000 sets;In 1997, it increased to 1 million pixels, and the number of digital cameras shipped exceeded 1 million.
1996OLYMPUSandCanonThe company also launched its own digital camera.Then Fuji, Konica, Minolta, NikonRicoh、Constex、Sony, ToshibaJVC、SanyoNearly 20 companies have participated in the R&D and production of digital cameras and launched their own digital cameras.
In November 1997, Kodak released the DC210 zoom digital camera, which uses 1.09 million square pixelsCCD image sensor；Fuji released the DC-300 digital camera.
In 1997, Olympus first launched the CA-MEDIAC-1400L model with "super million" pixelsSLRDigital cameras have caused great shock in the industry.
1997 PMA InternationalCamera EquipmentOne of the most remarkable features of the Expo is that the combination of traditional photographic equipment and computer information processing makes image intake and transmission becomephotoelectronThe industry and the computer industry share the same cause, and some IT manufacturers have begun to participate in digital photography.Major companies have launched more popular digital cameras of less than 1000 dollars, and the cheapest one can be less than 200 dollars, which has created conditions for digital cameras to enter ordinary families.
The hot spots and mainstream products of popular digital cameras in 1997 areCCD pixelAbout 350000, the largestResolving power640 × 480 pixel digital camera.And“Megapixel”(megapixel) cameras are "emerging", onlyFuji Film CompanyOlympus, Kodak and Konica each launched a new product.The focus of the development of universal digital cameras is to develop them in addition to improving the resolutionSpecial functionsIs traditionfilm camera Some functions that are not available or impossible to display the advantages of digital cameras, such as equipment on the bodyLCD monitoring screenIt is used as a viewfinder and can check the shooting effect on the spot after shooting. The lens can be made into a function that can rotate a certain number of degrees. It is installed in combination with the function of LCD screen to facilitate self shootingImage dataFast transfer of computer functions.
（3） 1998Fuji filmThe company launched the first million level (1.5 million pixels) lightest and smallest, popular edge NEPIX700 digital camera;Canon and KodakCooperative developmentThe first one equipped withLCDmonitorEOSD2000 and EOSD6000 digital SLR cameras.
1998 was the year when the low-cost "megapixel" digital camera became a new hotspot and mainstream product. More than 60 new models were published or sold that year, and more than 20 manufacturers: Casio (4)Fuji film(8 kinds)Kodak(4 types)Minolta(3 types)Nikon (3 types)Canon(4 types)OLYMPUS(4), Sanyo (6), Sony (6), SeikoEpson(4 types). The two types of release include“Akfa、HP, KonicaPhilipsRicoh;Toshiba, PanasonicHitachi、JVC、Kyocera, LeicaSamsungAnd Chinese seagulls.Among them, new products that reach or exceed "megapixel" account for about 80% of all new models.Canon with a maximum of 1.68 million pixelsPowerShotPro70 digital camera with 2.5x optical zoom and 2xDigital zoom ，TTLAutomatic digital camera focusingAuto exposure2 inch color TPY LCD screen, with a speed of 4 frames per second and a maximum of 5 seconds.
In 1998, digital cameras made great efforts in terms of functions, which can be summarized as follows:
one
Using opticsZoom lens。There are 2 times, 2.5 times, 3 times, 5 times and 10 times, up to 14 times.In addition, some cameras also have a digital zoom function, which is 2x or 4x.
two
It has the function of connecting external flash lamp.Some models have the functions of built-in flash and external synchronous flash.
three
Equipped with exchangeable "lens CCD" unit, it has the ability to expand systematization.
four
With TTL optical viewfinder orSLR shootingFunction of.
five
Single reflex interchangeable lens function.
six
yesManual focus、aperturePriority andshutterPriority control of exposure and other parameters can be automatically set.
seven
After installing the "Digita" digital image special operating system, new functions such as shooting program setting have been added (installed in Kodak, Minolta and other series of products).
no needpersonal computerConnection, direct (orSM cardAnd other recording media)printerThe function of printing digital photos.
Typical digital camera products in 1998 include:
one
Kodak DC260 digital camera: 1.6 million pixel CCD image sensor;3x optical zoom and 2x digital zoom;Can be connected to flash sync line;Shutter priority, aperture priority, automatic exposure function, with shooting program preset function;USB interface, etc.
two
Casio QV-7000SX digital camera: launched in September 1998, it is the highest grade product in OV series.2x optical zoom and 4x digital zoom, aperture priority automatic exposure, 7 kinds of operation parameter customization functions.In addition, there are passive automatic focusing or manual focusing of phase difference, multi zone metering or spot metering, LCD display, image twice magnification, automatic date recording, HTML file generation and multiple shooting functions.
three
Minolta DemageEX seriesdigital camera: It was launched in October 1998, including EXzoom 1500 and EXwiea1500;The former is equipped with a 3x zoom lens - CCD unit (7 － 216mm/F3.5 － 5.6), and the latter is equipped with a large aperturewide-angle lens——- CCD unit (5.2mm/F1.9), its common features: 1/2 inch 1.5 million pixel primary color sequential scanning CCD3 is equipped with a dedicated "Didta" digital image dedicated operating system, which has software scalability; it has 3.5 frames per second, up to 7 framescontinuous shooting ；5 scenarios can be set;It has the same operation performance as traditional film.
four
MinoltaDemageRD3000 digital camera is based on "APS"SLR cameraBased on S-1, the interchangeable lens SLR digital machine uses two CCD image sensors with a total of 2.7 million pixels.
five
Waterproof and dust-proof "megapixel" machine appeared on the stage
Fuji film BigJobDS － 25OHD digital camera is based on Fuji CCDTotal pixelsBased on the 1.5 million FinePix700 cameraJapanese Industrial StandardSpecial jacket with level 7 protection capability, plus large size of HD back and GN24flash lampComposed of "megapixel"Waterproof and dustproofDedicated digital camera.
Konica DG-1 digital camera was launched in September 1998 and also has a 7-level waterproof and dust-proof design, with a total of 1.08 million pixels.Rigid body and important partsrubberMaterials shall be protected.Suitable forCivil worksFor on-site monitoring, the image can be immediately transmitted and printed into the project records and operation report documents.
In addition, some companies have developed special waterproof and dust-proof jackets. For example, Kodak has launched waterproof and dust-proof jackets that can be used in 3m deep water and are used for three models, namely, DC200, DC210Zoom and DC210AZoom. 3 Canon has also launched special waterproof jackets for two models, namely, PowerShotA5 and A5zoom.
Sony introduced a new type of storage media - "memory stick" to the market in September 1998, which has two capacities: 4MB MSA-4A and 8MB MSA-8A.The volume is long and thin, which is very convenient to pull out or insert.Technical characteristics: 10 pin connector, serial interface, maximum write speed 1.5MB/S, maximum read speed 2.45MB/S, power supply voltage 2.7-3.6V, operatingAverage consumptionThe current is about 45mA, and the maximum is 130mA in standby mode,Overall dimension：21.5×50×2.8mm；It weighs about 4g.
At the same time, MSAC-PCI PC card is also introducedAdapter。
Sony's new SLR digital camera CyberShotPRODSC with "memory stick"D700, 5xZoom lens(equivalent35mm cameraFocus 28 － 140mm/f2 － 2.4) 1.5 million pixel CCD, 2.5 inch display screen, rich in functions, suitable for professional use such as studio.
8. General decline in price positioning
At the beginning, the price of universal digital cameras was about US $1000 for the US market and less than 200000 yen for the Japanese market.Products at that timeCCD image sensorThe total number of pixels is generally 300-350000 pixels.By the end of 1998, the price of digital cameras had dropped significantly. For example, the Ricoh RDC-4200 digital camera with 3 times zoom of "megapixel" had a minimum price of 499 dollars, while the price of similar cameras in 1997market priceIt is about US $1300, which shows that the price has dropped significantly.Many products, on the one hand, increase functions and performance, on the other hand, reduce price positioning, such asFuji Film CompanyThe DS-330 digital camera launched in June 1998 is more convenient than the DS-300 camera launched in April 1997, and its price is reduced by 5000 yen (productCatalog Price190000 yen);Nikon Corporation The CooLPIX910 camera with 3x zoom and many additional functions launched in October 1998 and the C00LPIX90 camera with basically similar appearance launched in April of the same year reduced the price by about 10000 yen, and the attachedCF cardAlso changed from 4MB to 8MB.
Flash Memory Card -——CF cardandSM card, the capacity is increasing, and the price has also dropped a lotMBIt is 7-10 US dollars, which is about half of that in 1997.(Attachment: CF card: the maximum capacity provided by SanDisk Company in the United States is 48MB; the maximum capacity provided by LexarMedia Company is 64MB3 in JapanPanasonicBatteryIndustrial companies can provide 4, 8, 12, 16, 24, 32 (MB) CF cards;Casio can provide 4, 8, 15, 30, 48 (MB) CF cards.SM card: Japan Toshiba Company, the main manufacturer, can provide varieties with a maximum capacity of 16MB.SM cards with capacities of 2, 4, 8 and 16 (MB) are available in the US market.
（4） 1999 - the year of 2 million pixels
1999 was the year when portable digital cameras entered 2 million pixels.In more than a year, the major camera manufacturers in the world have put more than 100 digital cameras on the market.
In 1999, more than 20 kinds of portable digital cameras with more than 2 million pixels were introduced to the market. They have their own characteristics and represent the progress of the times, such as Canon PowerShotS10,Kodak DC280, DC290Zoom, Fuji MX-2700MX－2900Zoom、PrintCamPR21、Nikon Coolpix700Coolpix800、Coo1pix950，Olympus C21、C－2000Zoom、C－2020Zoom、C－2500L，Ricoh RDC － 5000, Casio QV － 2000UX, Sony Cyber shotDSC F55ECyber－ShotDSC－F505，Epson PhotoPC800, PhotoPC850, Konica Q-M200, etcMP(MP stands for megapixel) is the leader of portable digital camera.
2、 Development of Universal Digital Camera in 2000
From the birth of commercial digital cameras to the year 2000, it was less than 10 years for professional cameras and only 6 years for popular camerasDevelopment speedIt's amazing. It was popular in 1998new product development The hot spot is at the level of 1 million pixels. In 1999, the hot spot climbed to the level of 2 million pixels (2MP). In 2000, the hot spot was upgraded to the level of 3 million pixels (3MP). In October 2000, Olympus launched theNumber of pixelsCAMEDIAE-10 universal digital camera with 4-megapixel 4x optical zoom set a new record in 2000.
Authentic anti-counterfeitingTrademark printingExquisite, strong viscosity, the lower layer of digital adhesive tape cannot be removed, while the fake anti-counterfeit trademarks are poorly printed, and the lower layer of digital adhesive tape can be removed easily. Some fake anti-counterfeit trademarks have not yet been produced by manufacturers800 phone。
Call 800
800 telephone serviceCalled centralized payment serviceorToll freeBusiness is the service number that enterprises set up to contact customers and promote their corporate image. Generally speaking, it is free to make calls and charge for answering calls.Therefore, all major manufacturers of digital cameras have set up their own 800 telephones to receive inquiries from consumers. When buying a camera, they can directly call the dealer's telephone number, so that they can know if it is fake.
Online inquiry
Each digital camera manufacturer has a website with powerful functions and beautiful pages.Can accept consumer consultation and downloadDriverThe consumer can check online at the dealer.
Read the manual
When buying a digital camera, you must pay attention to the printing quality of the manual and warranty card. Generally, the Chinese manual of the smuggled goods is printed by the smuggler himself. In order to save costs, its printing quality is very poor, and there are missing pages or blurred handwriting. It is easy to see if you carefully distinguish between them.
Whether the numbers are consistent
The number on the camera body, the number on the outer packing box and the number on the warranty card should be consistent.
milepost
Sony Mavica ——The first electronic camera without photographic film
In November 1973, Sony officially started the research work of "electronic eye" CCDTechnical accumulationIn 1981, it launched the world's first electronic camera without photographic film - the still video "MABIKA".The camera uses a 10 mm × 12 mm CCD chip with a resolution of only 570 × 490 (279000) pixels. It is the first time to change the optical signal to electronic signal transmission.
Followed by,Panasonic, COPAL, FujiCanon、Nikon Other companies have also started the development of electronic cameras, and launched their own prototype electronic cameras in 1984-1986.
Sony MYC-A7AF——For the first time, the digital camera has a purely physical operation method
The second camera that is a milestone in the history of DC industry is alsoSonyIt can be seen that the company has achievedmarket position It is by no means a "false name for waves".In 1986, Sony released MYC-A7AF, which for the first time enabled a digital camera to have a purely physical method of operation, capable of recording still images on a 2-inch discresolving powerIt has also expanded to 380000 pixels.
In 1987, Casio first sold the VS-101 electronic camera using CMOS photosensitive devices on the market. Although the resolution can only reach 280000 pixels, this is of great significance to the DC industry.
Today, CMOS is widely used in today's Canon high-end cameras. Other manufacturersAll haveTake CCD as the leading direction of their products.
Want to get close toTraditional cameraThe most fundamental solution is to improve the CCD pixel resolution. Canon launched the 600000 pixel model RC-760 in 1988.
This electronic camera uses a 2/3-inch 600000 pixel CCD, which looks a little stiff today, but it was the highest pixel machine in that era, and the price is more expensive than a car today.
Product classification
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SLR camera
Nikon D7000 SLR camera
SLR digital cameraIt meansSingle lensReflective digital camera, that is, digital digital, single, lens lens, reflex reflective English abbreviation dslr.Typical models in the market are commonly found inNikon 、Canon、Pentax, Fuji, etc.Such cameras are generally large and heavy.
useElectronic viewfinderThe model of evf is also includedSLRClass, but generally annotated with "similar", or indicated as evf shooting, such asOLYMPUSc- 2100uz、Fuji finepix 6900, etc.In the working system of the SLR digital camera, light reaches through the lensreflectorAfter refractionfocusing screenAnd form an image throughEyepieceandPentaprism, we canviewfinder See the scenery outside.In contrast, general digital cameras can only use the LCD screen orelectronic viewfinder The device (evf) sees the captured image.Obviously, the image seen directly is more conducive to shooting than the image seen through processing.
A great feature of SLR digital cameras is that they can exchange lenses of different specificationsSLR cameraNatural advantages are incomparable to ordinary digital cameras.
SLR (Single Lens Reflex) refers to single lens reflection, which is the most popular viewfinder system today. Most 35mm cameras use SLR (Single Lens Reflex)viewfinder。In this system,reflectorAnd the unique design of prism enables the photographer to directly observe the image passing through the lens from the viewfinder.
Micro single camera
Digital camera
MicrosingleIt has two meanings: micro, micro compact, single, replaceable single lens camera, which means that this kind of camera has a compact volume and a general image quality of SLR, that is, the micro compact and SLR capable camera is calledMicro single camera。Ordinary card digital cameras are very fashionable, but they are limited by aperture andLens sizeThere are always some beautiful scenes that cannot be photographed;Professional SLR cameras are too bulky.As a result, the micro single camera came into being.
Main features: WeChat has removed thereflector panelAnd set-top viewfinder system, modified thefocus system Without reflector, there is no reflection of light, so you can't see the scene directly through the lens. In this case, you have to open another viewfinder, and then the sameThe card machineSame passLCD viewfinderAt the same time, it can improve the compactness of the micro single body. Of course, the focusing performance is different. The focusing performance of the SLR isPhase focusing, while micro single uses contrast focusing, and contrast focusing requires repeated detection of contrast during focusing. WhenFocusingAfter that, you may continue to focus too much, and then return to the focusing position, which will be a little slower than the phase focusing. The phase focusing can be directly to the focusing position at the beginning, and it does not need to focus too much, which can save some time and will be faster.
OlympusPanasonicThe new micro unit adopts the high detection frequency contrast focusing function,Focus speedIt can achieve or even exceed the focusing speed of the SLR. It seems that this technology is sufficient to fill the shortage of slow micro single focusing. In fact, the contrast focusing has another advantage that it does not run out of focus, and it can achieve accurate focusing without cross double cross focusing. The improvement of this technology adds a lot of color to micro single products.
Card camera
Samsung card camera
Card cameraThere is no clear concept in the industry. It only refers to those compact shapes, relatively light bodies and ultra-thin and fashionable designs that are the main criteria for measuring such digital cameras.amongSonyT series, Olympus AZ1 andCASIOZ series should be divided into this field.
Main features:Card digital cameraIt can be carried with no burden;And inFormal occasionsPut them inman 's suitThe coat will not be deformed due to falling in the pocket;Ladies' littleHandbagIt is no longer difficult to find space to squeeze them;Stuck the camera in other occasionsJeansPockets or simply hanging around the neck are also acceptable.Although they are not powerful, the most basicExposure compensationThe function of the ultra-thin digital cameraStandard configuration, plus areas or pointsMetering mode, theseSmall thingsSometimes I can still complete some photography creation.At least your exposure to the picture can haveBasic controlWith colordefinition, contrast and other options. Many beautiful photos can also come from these small things that are not appreciated by "experts".
Difference between card camera and other cameras: advantages: fashionable appearance, large LCD screen, small and thin body, convenient operation.Disadvantages: the manual function is relatively weak and oversizedLCDLarge power consumptionLens performancePoor.
Telephoto camera
Long focus digital cameraIt refers to the largeOptical Zoom The larger the optical zoom factor, the farther the scene can be photographed.Representative models are:MinoltaZ series, Panasonic FX series, Fuji S seriesKodakDX series, etc.
Main features: The main features of a telephoto digital camera are similar to the principle of a telescope. The focal length is changed by the movement of the lens inside the lens.The benefits of telephoto are brought into play when people shoot distant scenes or when the subject does not want to be disturbed.In addition, the longer the focal length isDepth of fieldThe shallower, the same effect as the larger the aperture, the shallower the depth of field. The advantage of shallow depth of field is to highlight the subject and blur the background. It is believed that many FANS pursue a shallow depth of field effect when taking photos, which makes photos more professional.In some digital cameras with longer lenses, the internal lenses and sensors have more room to move, so the zoom ratio is larger.Today's digital camerasOptical zoomThe multiples are mostly between 3 and 12 times, which can bring objects 10 meters away to 5-3 meters;Some digital cameras also have 10x optical zoom.The optical zoom ratio of household camera is 10-22 times. If the optical zoom ratio is not enough, people can add a magnification lens in front of the lens. The calculation method is as follows:TelephotoscopeIf it is mounted on a digital camera with a 4x optical zoom, the optical zoom times of this digital camera will be changed from the original 1x, 2x, 3x, 4x to 2x, 4x, 6x and 8x, that is, multiplied by the magnification lens and the optical zoom times.
Digital camera
data storage
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Audio visual of digital cameraStorage formatThere are roughly the following types.
ExtensionIsThe AV format of AVI is one of the earliest popularized specifications.becauseAVIThe format is not compressed, so the AVI audio and video files of only tens of seconds often need 5-8MBstorage space 。In addition, since there is no complete set of specifications for manufacturers using AVI format as a reference, there are at least more than 100 specifications deduced by each company.Although popular video playing software, such as WINDVD, POWERDVD, and even AcdSee 3R-1Equal signIt is said that more than 60%~70% AVI files can be played.However, MicroSoft Mediea Player 8.0 isCompatibilityBest AVI video player software.At present, it is the most common dynamic image format.
MOV
MOV is one of the most popular animation formats adopted by most digital camera manufacturers.The main reason is its simplifiedcompression technique , provides users with good audio and video options at low resolution, plus playback softwareQuickTimeobtainAppleThe free authorized use of computers naturally adds to itsPenetration rate。QuickTime version 4.12 or above can not only handle video, animation, graphics, text, sound, even 360 degreesVirtual reality(VR) is not a problem.
becauseJPEGThe full-color image standard is adopted, and the unique distortion compression technology DCT is used to remove the less important parts of the image data, effectively reducing the file size.Combining animation playback capability with JPEG is calledMJPEGIt is the abbreviation of Motion JPEG.The stored extension still uses AVI to match thecompatibility。Due to the simple image specification and small memory capacity, many images do not support synchronizationRadio functionDigital cameras, such as Nikon CoolPix 9XX series and some simple video conferencingIP Camera , like this format.
along withVCDWith the increasing popularity ofMPEG-1The technology of.Although, only a few digital cameras can support this specification of animation recording (most of them are Japanese SONY).Its combination specialtyCCD, the combination result of shot and animation technology, andDVIt's almost as good as it is.MPEG's full name is Moving Picture Experts Group, which belongs to ISO/IEC standards（International Standards OrganizationAnd the International Association for Electronic Technology).By playing the program'sdecodingMPEG-1 technology enables long time electronic image to make fast turn, rewind and even choicepoint of timeThese actions.The files recorded with MPG can also be directly recorded on the VCD and viewed through the VCD Player.
ASF
The introduction of MPEG-1 has brought at least two revolutions to the computer world. One is to make the electronic animation files recorded for a long time have the search function, and the other is to suppress MP3 music comprehensively.As the major record companies have long been troubled by MP3, they must replace MP3 with a more strict sound effect format that is not easy to be copied when developing a new generation of AV technology.Microsoft, as the leader of software industry（MicrosoftThe company is fully committed to promoting the popularization of ASF format:ASF formatThe feature of is that the image part adopts the latestMPEG4Compression mode, and the sound part is developed by itselfWMAFormat (WMA emphasizes itsCompression ratioMP3 is twice as strong as MP3, and its sound quality is similar to that of WMAConfidentialityIt is not as easy to copy as MP3.).
In order to avoid the copyright dispute of WMA sound effects, the industry has adopted a new type of MP3DIVXAudio visual format.DIVX compresses video with MPEG4, audio with MP3, and stores it in AVI file format!.However, the CODEC of DIVX must be downloaded when playing the image files of DIVX specifications, plus thesystem resourceVery high requirements, at least in AMD K-350 or Pentium II 300CPUTo play successfully.In the visible future, unless the digital AV IC'sprocessing speed Otherwise, we will not see the digital video recording equipment with this specification on the market in a short time.
RM
RealVideoyesRealNetworksThe real-time playback software specially developed for network audio and video allows web page producers to provide real-time audio and video programs on the website.Also developed by RealNetworksRealAudio, you can provide real-time playback of sound on the website.Users can find a free download at the following websiteRealPlayerSoftware and information.In addition, RM can also support direct playback of online Stream Line without downloading the entire video file.However, because the disadvantages of poor RM image quality cannot be effectively solved, there is no digital camera supporting RM recording format on the market.However, at present, some low-end digital camera manufacturers in China have obtained RM's authorization and are developing technologies in this regard. I believe that support will be available in the near futureRM formatNetwork digital camera of.
GIFStrictly speaking, it only countsMotion picturePresentation format.Only 256 colors are supportedColor scale, cannot record.The standard specifications are also divided into GIF87a and GIF89a. Only GIF89a has the ability to play transparent backgrounds and animations.For digital camera applications, only SONY can directly produce GIF CLIP.
Main accessories
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UV lens
Filter excess in airultraviolet rays, at the same timeProtective glassesThe role of the head.UV brand, such as;Corn，KengoThe prices of Hassan, B+W, and the original lenses of some big brands are also uneven: for example, from tens to hundreds of yuan.Pay attention to the following when selectingUV mirrorThere is coating on the surface of the lens. Especially when we shake under strong light, we can see colorful colors. The light transmission performance is very good. When you put the lens in front of your eyes, you can't see the lens.The lenses worth tens of yuan are not UV lenses (called protective lenses) strictly. First of all, the lenses are not coated (without coating, there is no function above the UV lens, just to protect the lens from falling ash). Putting them on the lens is like adding a high-end glass.The imaging effect is not as good as that without lenses.
Mainly to preventLCD screenThe function of scratch is:Electrostatic adsorptionIf the surface of the LCD screen is scratched seriously for a long time, the protective film can be replaced in time. At the same time, the surface of the LCD screen is not damagedCorrosion。(For example, the film used on mobile phones is glued to the surface of the LCD screen and cannot be replaced).
Air blowing
Clean the dust on the lens and camera surface, but pay attention when cleaning. The blow head must be a certain distance from the lens, and blow hard with the palm of your hand (this can ensure that the blow head will not beInattentionThe lens is scratched when it is touched.)
Lens cloth
It should be used in conjunction with air blowing. When wiping the lens, do not blow the dust on the lens with your mouth to avoid your saliva on the lens (especially after eating greasy food, once the lens is stained with greasy saliva, it is not easy to wipe)
First of all, you should choose the performance of the camera bag (that is, what do you want to buy the bag for), such as rain proof, shock proof, dustproof, fireproof, etc.There are many kinds of camera bags on the market:JEEP，Le Chateau, Weifeng, Buckingham, Rihua, Buster,Gitoshiwait.
Charging interface
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On October 4, 2022 local time,European parliamentThrough the unified portableIntelligent deviceAct on charging interface.It is stipulated that all new portable intelligent devices such as digital cameras must be used from the end of 2024USB Type-CCharging interface.[1]
AE is the abbreviation of automatic exposure control device. AE lock is locked to a certain AE settingAuto exposureHuman controlExposureTo ensure normal exposure of the main body.
There are several points to note when using the AE lock:
1. Automatic exposure (AE) lock cannot be used in manual mode or self timer.
2. Do not adjust the aperture size after pressing the AE lock.
3. Useflash lampDo not use the (AE) lock when photographing.
CCD
Chinese translation:Electronic coupling assembly(charged coupled device), which is likeTraditional cameraLike the negative film of, it is a circuit device that senses light. You can imagine it as tiny inductive particles, which are covered withOptical lensAt the rear, when the light and image pass through the lens and project onto the CCD surface, the CCD will generate current to convert the sensed content into digital data for storage.CCDNumber of pixelsThe more eyes and the larger the size of a single pixel, the clearer the collected image will be.Therefore, although the number of CCD is not determinedImage qualityIt can still be regarded as one of the important criteria for camera grade.
CMOS
CMOS，complementary metal-oxide-semiconductor。Complementary metal oxide semiconductor.Early CMOS was a single chip MC146818A（DIP package）, 64 bytes in totalsystem information 。With the development of microcomputer and the increase of settable parameters, CMOS RAM generally has a capacity of 128 bytes to 256 bytes.Today, CMOSmanufacturing processAlso used in productionDigital videoEquipmentPhotosensitive element, especiallySheetLarge monocular digital camera.Although in terms of usecmos circuits Mainly used as firmware orcomputing equipmentThe use of CMOS is very different, but basically it still adopts CMOS technology.
DPOF
DPOF refers to the digital printing sequence instruction, which is used instorage medium (ImageMemory cardAnd so on).In this format, you can set the number of images taken by the digital camera to be printed and how many to print.
EXIF
The so-called EXIF (exchangeable image file format for digital still cameras) is created by jeita（Electronic Information Technology Industry Association）A specification established to determine how additional information is recorded on jpeg images and sound files.
EXIF 2.2
EXIF 2.2Edition is a new version of digital camerafile format, which contains various shooting information necessary for optimal printing.
PTP
PTPIt is the abbreviation of English picture transfer protocol.PTP is the earliestKodakAndMicrosoftA standard formulated through negotiation. Image devices conforming to this standard are accessedWindows XPThe system can be better used by the system andapplication programShared, especially innetwork transmissionThe system is OKDirect accessThese devices are used to establishNetwork albumUploadOnline chatWhen the picture transmission.Of course, this is mainly for convenienceComputer knowledgeNot many ordinary users make cameras, applications, websitesCombined, it is easier to complete some fool like functions.
GT lensMeansMinoltaUnique designed multi piece and multi group with ingenious lens components, the use of high-end lens is lowdispersionoptical glass, which includes multiple die castingAspherical lens wait.That is to say, Minolta's G-series high-end professional traditional camera（Silver saltCamera) is called AF lens, and Minolta will produceProcess technologyApplied to the design and production of digital cameras, the products produced are called GT lenses.
I.ezeiss。ZEISS is a company dedicated to application researchproduct development Since 1846, carl zeiss has set up a workshop to produce microscopes.Zeiss lens, professional camera, camera lens
I.ewide angle, also calledShort focal lens。The wide-angle lens has a very short focal length, so the scene projected on the film becomes smaller and widerShooting angleIn addition to taking more scenes, it can also take images from a wide angle in a narrow environment.
Number of pixels
The number of pixels in a digital camera includesEffective pixel(Effective Pixels) andMaximum pixels（Maximum Pixels）。Different from the maximum pixelNumber of effective pixelsIt refers to those who really participate in photosensitive imagingPixel value, and the value of the highest pixel isPhotosensitive deviceThe data usually includes the non imaging part of the photosensitive device, while the effective pixel is in the lensZoom magnificationThe converted value under.For the digital camera pixel of mobile phone, it can only be at the primary levelDevelopment stageThe number of pixels is not very high, mostly between 100000 and 1.3 million pixels.The larger the number of pixels in the digital camera, the greater the resolution of the still image taken, and the corresponding space occupied by a picture will also increase.
resolving power
Resolution and pixel are two very similar concepts, but they are different.In terms of relationship, resolution refers to the number of pixels per unit imaging size.Generally speaking, the larger the pixel, the higher the resolution.For a picture, the pixels are fixed, but the resolution can be changed at any time. As the image is enlarged, the resolution will gradually decrease.
IESP English abbreviation for intelligent electronic selection pattern.IESP autofocus is a digital cameraFocus Range Multiple block segmentation is performed internally (some data say that the segmentation method is sector segmentation), and then the focus position measured in the segmented block is comprehensively calculated to determine the best focus position according to the different states of the main body.IESP automatically focuses onOlympus digital cameraIt is often seen in the introduction of.
Zoom
Another focus of the lens is the zoom ability, which includesOptical zoom(optical zoom) anddigital zoom(digital zoom).Although both of them are helpful to magnify the remote object during the telephoto shooting, only the optical zoom can support the image subject to add more pixels after imaging, making the subject not only larger, but also relatively clearer.Generally, the larger the zoom factor is, the more suitable it is for telephoto.Like traditional camera design, optical zoom depends on the focal length of the lens, so the resolution and image quality will not change.Digital zoom can onlyImage sizeCropping makes the image larger on the LCD screen, but it will not help to make the details clearer.
Optical zoom
Optical zoom depends on opticsLens structureTo achieve zoom,Zoom modeAnd35mm cameraAlmost, it is to zoom in and out by moving the lens of the camera,Optical Zoom The larger the object, the farther it can be photographed.Most digital cameras today have an optical zoom of 2-5 times, and some cameras have an optical zoom of 10 times.The optical zoom ratio of the home video camera is 10~22 times, which can clearly shoot things 70 meters away.useMultiplier mirrorIt can increase the optical zoom multiple of the camera.
digital zoom
The digital zoom is actually the electronic magnification of the image, which converts the original CCD imagea sensorSome pixels on the“interpolation”The processing means is to magnify, and the pixels on the CCD image sensor are used to enlarge the picture to the whole picture with interpolation algorithm.adoptdigital zoom, the scene is enlarged, but itsdefinitionIt will decrease to a certain extent, like VCD orDVDThe zoom function in, so digital zoom does not have much practical significance.
New and uniquesonyIntelligent zoomFunction. EnlargeableZoom shootingIt will not magnify the particles, so that the magnified image can also maintain the original fine quality. The intelligent zoom provides different levels of enhanced zoom function according to the selection of different image sizes. Unlike digital zoom, the intelligent zoom can maintain the same image quality as the original image.
Programmed automatic exposure is the combination of electronic technology and artificial intelligence. When exposed in this way, the camera can not only calculate the appropriate exposure amount according to the light conditions, but alsoAuto SelectappropriateExposure combination。
Because of the back of the lensDepth of fieldRelatively large, people call the clear imaging distance behind the focus as the super focus.The scene within the super focus range is not really clear. Since it is not in the focus, it must be blurred, but the degree of blurring is generally acceptable. This isPoint and shoot cameraThe reason why the film cannot be enlarged too much.
LCD viewfinderLiquid crystal display,LCD。There are black and white and color, and there are true color and false color in color. False color is cheap, but the effect is poor.In digital camerasLCDAlmost all are the best at presentTFTTrue color.In TFT LCD, there are reflection andtransmissionTwo, reflective frontAmbient lightWork, the difference is large from different angles, the display is dark, but it saves electricity and costs less;The light behind the transmissive backrest works with small angle change and bright display, but it is extremely power consuming.
OLED, Organic Light Emitting Diode, OLEDdisplay technique It has the characteristics of self illumination, and uses very thin organic material coating andGlass substrateWhen there is current, these organic materials will emit light, and OLEDdisplay screenviewing angle Large, and can significantly save power.
TTL SLR
This is a necessary way of view taking for professional cameras, and it is also a truly error free optical way of view taking.suchviewfinderThe range of view can reach 95% of the real picture.The only disadvantage is that if the lens is too small, the viewfinder will be very dark, affectingManual focus。Fortunately, they all haveAutofocusThis shortcoming is no longer serious.Of course, we used ttlSLR shootingIn order not to be too dark, manufacturers will use large caliber advanced lenses, so semi professional cameras are generally equipped with such lenses.OLYMPUS(olympus) cameras often use this viewfinder.
electronic viewfinder EVFVisual field ratethanOptical viewfinderIt is much larger. For example, the EVF of Sony DSC-f707 has a field of view rate of 99%.andElectronic viewfinderIt is also more practical. This kind of shooting method is not only cheaper, but also can save electricity when usingAmbient lightUsed below.Although the view angle and color effect of the picture in the viewfinder are not all the same as the final result, they will adapt quickly after a period of use.
Optical viewfinder
The type commonly used in traditional popular cameras has nothing to do with the shooting lens through a group of camerasZoom lensLinked) lens viewfinder, low cost, butparallaxWhat you see is not exactly what you see.
This is the most common way of shooting, and its only disadvantage is that the shooting error is large.Those who have used digital cameras must know that the optical viewfinder of digital cameras, when shooting at close rangeposition error The error with the actual shooting scene is very large (the distance is not particularly obvious). Generally speaking, the scene seen by the optical viewfinder accounts for about 85% of the actual shooting scene.
Equipped with three typesMetering mode: Fixed point metering, central weighted metering and multiple metering modes to meet different photographic conditions and purposes.The multiple metering mode divides the image into 49 areas, and meters light for each area, so that the photographed image can obtain a balanced exposure.
Bracketing is an advanced function of the camera.Surrounding exposure means that when you press the shutter, the camera does not take one picture, but takes several pictures in succession with different exposure combinations, so as to ensure that there is always one picture that meets the photographer's exposure intention.When using the bracketing exposure, you need to set it to the bracketing exposure mode first. When shooting, just shoot as usual.Surrounding exposure is generally used for still or slow moving shooting objects, because it is difficult to capture multiple pictures continuouslyMoving bodyThe best time to shoot.
The special pre flash exposure function can be used in general shooting orMacroWhen shooting, use the pre flash receivedimage data, can more accurately measure the flash intensity andExposure valueTo make the captured image get better exposure.
It refers to the phenomenon that when taking a portrait with flash light, there is a red spot in the eye of the person in the picture due to the reflection of the eyeground blood vessels of the subject.But most mainstream digital cameras haveRed eye prevention function, but if it is not opened, it will still not work.
Digital cameraAnti hand shock functionThere are two kinds: optical and digital.OpticalAnti hand shockIt is the same as the traditional camera. The lens designed by the special envoy is set in the imaging optical path, which can sense the vibration of the camera, and automatically adjust the optical path according to the characteristics and degree of vibration, so as to stabilize the imaging.
interpolation
interpolation(interpolation), sometimes called "reset sample", is added without generating pixelsImage pixelsA method of size, based on the color of surrounding pixelsmathematical formula Calculate the color of the missing pixels.Some cameras use interpolation to artificially increase the image resolution.
TTL metering
That is, TTL light measuring.Measured by lensLuminous flux, andFilterThe exposure, aperture and focal length are independent of other parameters.Metering modeDivided into average, local,center weighted Etc.Any method of light measurement is much the same, but like backlighting,SubjectsThe contrast between light and shade ofPhotomicrographyAnd other methods, there will be different differences.
ISO sensitivity value is a measurement value of the sensitivity of traditional camera film to light. It is usually expressed in ISO numbers. The larger the number, the more sensitive it isoptical rotationThe stronger, the more commonly used are ISO 100, 400, 1000, etc. Generally speaking,SensitivityThe higher the film is, the thicker the film grain is, and the effect after magnification is poor. The digital camera is also marked by this ISO valuePhotometric systemThe lower the reference ISO, the higher the required exposure.
The digital photos on the memory card can be restored just like the digital photos that have been copied to the computer.
nineteenInfluence of resolution during shooting
High resolution can be obtainedhigh-precisionImages, but digital photos should beimage fileAs the resolution increases, the image file will also increase, and the time for digital cameras to process images will increase.
twentySelection of resolution during shooting
The purpose of the captured image is the main reason that affects which resolution level needs to be selected for shooting.
twenty-onePrinting size and shooting parameters
For a digital photo with a resolution of 1600 × 1200, the appropriate size of the print photo is calculated as 6 inches through the calculation method of 1600 ÷ 250=6.4 rounded to 6. Then you can multiply 6 by 250 to find that the resolution of 1600 × 1200 is appropriate.
Predefined white balance andAutomatic white balanceThe correction ability of is also limited. During automatic white balance, the color of the previous scene is particularly biased to a certain color, which may cause the problem that subsequent photos are biased to a certain color.
The advantage of measuring light through the lens is that it can directly reflect the size of the light of the scene seen, that is, the light is projected on the photosensitive element through the lens, and the photosensitive element transmits the light signal to the processing chip of the digital camera for analysis.
twenty-fourSensitivity setting
ISO (International Standards Organization) formulates industrial standardsInternational Standards OrganizationShort name of.film camera In industry standards,ISO StandardsTo measure the sensitivity of the film to light, the lower the value, the slower the exposure induction speed of the film.
twenty-fiveShutter control skills
commonshutter speedThere are: 1 1/2 1/4 1/8 1/15 1/30 1/60 1/125 1/250 1/500 1/1000 1/2000, etc., in seconds.Slow shutter can be 1 second, 2 seconds, 4 seconds or even longer.
Flash is a very convenient and suitable tool as a supplementary light source.But generally speaking, digital cameras that emphasize automation do not have a strong flash. At best, they program the flash function to provide "automatic", "mandatory"“red-eye ”, "Slow", etc.
twenty-nineUnderstand the differences between computer screens
First, you need to adjust the color of the computer screen so that the color displayed is consistent with the printer, and learn how to calculatePrintoutThe accuracy required for images of different quality (refer to the "Selection of resolution during shooting" described above).
Exif information is very useful, but it can also be easily destroyed.If you useWindowsXPIf you browse your digital photos with the image file view function of, the photographic information on the photos will be damaged.Photographic information will be destroyed, and once it is destroyed, it cannot be recovered.
If you have to use a digital camera in a humid environment, you can consider purchasing a waterproof cover for the camera.
Product standard
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Digital cameranational standardGB/T 29298-2012 General Specification for Digital (Code) Cameras was issued on December 31, 2012 and implemented on June 1, 2013.Digital camera brands useEnterprise standardHowever, there are differences among enterprise standards.
Purchasing method
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1. Lens selection
Lens: most friends do not change the lens frequently. The lenses of digital cameras are generally divided into optical zoom lens andFixed focus lens, forConsumer digital cameraFor example, the imaging quality of the optical zoom lens is much better than that of the fixed focus lensSLR camera lensOn the contrary, in consumer digital cameras, the workmanship and materials of the fixed focus lens are generally inferior to those of the optical zoom lens.
2. Usage selection
Travel and make friends, like shooting,Enthusiast, professionals.
3. Price selection
1500RMB, you can buy a 4x optical zoom ultra-thin camera.It performs well in the process of fast snapping - the subject is not always stationary, you know.
From 2000 to 2500, you can buy a camera with cash. It is very sweet, full of functions and small enough to fit your coat orJeansPockets.In this price range, the market is also full of a variety of models.
4000 Dayang has more choices for cameras.If you like shootingbirdYou can choose a camera with a built-in lens and a large focus if you want to take a picture of a beautiful woman in the opposite direction.
seven thousandRMB, must not be taking photos, but enjoying the process.
Can't use CCD or CMOS with digital cameraPhotosensitive elementTo measure the quality, the quality of CMOS sensor only depends on whether the manufacturing quality and technology are mature.
fourThe Importance of Lens
Digital cameraOptical lensThe resolution of the sensor must be better than that of the sensor.
fivePay attention to the details of the zoom function
The smaller the minimum focal length of a camera, itsWide angle shootingThe larger the range, the better for shooting large scenes, and the larger the maximum focal length, the stronger the telephoto ability.
sixCorrect interpretation of aperture size
Aperture refers to advancing in unit timeAmount of lightThe number of, that is, control the size of the area of light absorption sensor.
You should learn to distinguish between the product itself and the various documents provided.
fifteenDigital camera acceptance skills
The identification process starts with the packaging of the camera, and then checks whether there are scratches or other marks on important parts such as the lens, and then starts to try out the functions and performance of the camera, and finally checks the LCD screen and light-sensitive elementsBad spotAnd pay attention to checkwarranty cardDo not forget to ask for the invoice and the business card of the merchant to contact the merchant when necessary.
