digital camera or digicam is a camera that takes photos in digital memory. Most cameras produced today are digital, and while there are still compact cameras on the market, the use of dedicated digital cameras is reduced, as digital cameras are now incorporated into many devices ranging from mobile devices to vehicles. However, high-end and high-definition special cameras are still commonly used by professionals.
Digital cameras and film sharing optical systems, usually using a lens with a variable diaphragm to focus light onto the image capture device. The diaphragm and the shutter recognize the exact amount of light for the imager, just like the film but the image pickup device is electronic rather than chemical. However, unlike film cameras, digital cameras can display images on the screen as soon as they are recorded, and save and delete images from memory. Many digital cameras can also record moving video with sound. Some digital cameras can trim and stitch images and perform other basic image editing.
Video Digital camera
History
The history of digital cameras began with Eugene F. Lally from the Jet Propulsion Laboratory, who was thinking about how to use mosaic photosensors to capture digital images. His 1961 idea was to take pictures of planets and stars while traveling through space to provide information about the positions of astronauts. Like the naked cameras of Texas Instruments employees, Willis Adcock (US patent 4,057,830) in 1972, this technology still has to pursue the concept.
Cromemco Cyclops is an all-digital camera that was introduced as a commercial product in 1975. Its design was published as a hobby construction project in the Popular Electronics magazine magazine in February 1975, and it uses 32ÃÆ'â € "32 Metal Oxide Semiconductor Sensors.
Steven Sasson, an engineer at Eastman Kodak, invented and built the first self-contained electronic camera that uses charge-coupled device image sensors in 1975. Early uses were mainly military and scientific; followed by medical and news applications.
In 1986, the Japanese company Nikon introduced the first digital single-lens reflex (DSLR) camera, the Nikon SVC. In the mid to late 1990s, DSLR cameras became common among consumers. In the mid-2000s, DSLR cameras largely replaced film cameras.
In 2000, Sharp introduced the world's first digital camera phone, J-SH04 J-Phone, in Japan. In the mid-2000s, high-end phones have integrated digital cameras. In the early 2010s, almost all smartphones have integrated digital cameras.
Maps Digital camera
Image sensor
The two main types of digital image sensors are CCD and CMOS. The CCD sensor has one amplifier for all pixels, while each pixel in the active-pixel CMOS sensor has its own amplifier. Compared to CCD, CMOS sensors use less power. The camera with a small sensor uses a back-side-illuminated CMOS (BSI-CMOS) sensor. The overall image quality depends more on the camera's image processing capabilities than on the sensor type.
Sensor resolution
Digital camera resolutions are often limited by image sensors that convert light into discrete signals. The lighter the image at a particular point on the sensor, the greater the value being read for that pixel. Depending on the physical structure of the sensor, a color filter array can be used, requiring demosaicing to create colorful images. The number of pixels in the sensor determines the "number of pixels" of the camera. In a typical sensor, the number of pixels is the product of the number of rows and the number of columns. For example, 1,000 to 1,000 pixel sensors will have 1,000,000 pixels, or 1 megapixel.
Image sharpness
The final quality of an image depends on all the optical transformations in the chain producing the image. Carl Zeiss points out that the weakest link in the optical chain determines the quality of the final image. In the case of a digital camera, a simple way to express it is that the lens determines the maximum sharpness of the image when the image sensor determines the maximum resolution. Illustrations on the right can be said to compare lenses with very poor sharpness on high-resolution cameras, to lenses with good sharpness on lower-resolution cameras.
Shooting method
Since the first digital back is introduced, there are three main methods for capturing images, each based on hardware configurations of sensors and color filters.
Single-shot shooting system uses one of the sensor chips with a Bayer filter mosaic, or three separate image sensors (one for the main additive colors red, green, and blue) exposed to the same image via a divider file (see Three CCD camera).
Multi-shot exposes the sensor to the image in order of three or more aperture lens openings. There are several methods of applying multi-shot techniques. The most common initially is to use a single image sensor with three filters that are passed in front of the sensor in sequence to obtain additional color information. Another multiple shot method is called Microscanning. This method uses a single sensor chip with Bayer filter and physically removes the sensor in the focal plane of the lens to build a higher resolution image than the chip's native resolution. The third version combines two Bayer unfiltered methods on the chip.
The third method is called scanning because the sensor moves across the focal plane like the image scanner sensor. Linear or tri-linear sensors in the scanning camera use only one photo sensor line, or three lines for three colors. Scanning can be done by moving the sensor (for example, when using a sample co-site sampling) or by rotating the entire camera. A digital spinning line camera offers images with very high total resolution.
The choice of method for a particular retrieval is largely determined by the subject. It is usually inappropriate to try to catch a moving subject with anything but a single-shot system. However, higher color fidelity and larger file sizes and resolutions available with multi-shot and rear scanning make them attractive to commercial photographers working with silent subjects and large format photos.
The improvement of single-shot camera and image file processing at the beginning of the 21st century made the single shot camera almost completely dominant, even in high-end commercial photography.
Filter mosaic, interpolate, and aliasing
Most consumers of today's digital cameras use the Bayer filter mosaic in combination with optical anti-aliasing filters to reduce aliasing due to reduced sampling of different primary color images. The demosaicing algorithm is used to interpolate color information to create a full array of RGB image data.
Cameras using 3CCD single-shot beam-splitter approach, multi-shot three-filter approach, co-site sampling samples or Foveon X3 sensors do not use anti-aliasing filters, or demosaicing.
Firmware on camera, or software in a raw converter program like Adobe Camera Raw, interprets raw data from the sensor to get full color images, because the RGB color model requires three intensity values ​​for each pixel: one for red, green and blue (respectively) Other color models, when used, also require three or more values ​​per pixel). A single sensor element can not simultaneously record all three of these intensities, so an array color filter (CFA) must be used to select a specific color filter for each pixel.
The Bayer filter pattern is a repeating 2x2 light mosaic pattern, with the green in the opposite corner and red and blue in the other two positions. High green proportions take advantage of the nature of the human visual system, which determines the brightness of most of the green and is much more sensitive to brightness than hue or saturation. Sometimes a 4-color filter pattern is used, often involving two different green colors. This provides potentially more accurate colors, but requires a slightly more complicated interpolation process.
The value of the color intensity not captured for each pixel can be interpolated from the adjacent pixel value representing the color being calculated.
Sensor size and viewpoint
Cameras with digital image sensors smaller than 35mm film size generally have a smaller field or viewing angle when used with the same focal length lens. This is because the viewing angle is a function of both the focal length and the sensor or the size of the film used.
Plant factor relative to 35mm film format. If smaller sensors are used, as with most digicams, the field of view is trimmed by the sensor being smaller than the field of view of the full-frame 35mm format. This narrow field of view can be described as a pruning factor, a factor required by longer focal length lenses to obtain the same field of view on 35mm film cameras. Full-frame digital SLRs use sensors of the same size as 35mm film frames.
Common values ​​for the display field of plants in DSLR use active pixel sensors including 1.3x for multiple 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 Foveon and 2x sensors for Kodak and Panasonic 4/3-inch sensors currently used by Olympus and Panasonic. The crop factor for compact cameras and non-SLR consumer bridges is larger, often 4x or more.
Type of digital camera
Digital cameras come in a variety of sizes, prices and capabilities. In addition to general purpose digital cameras, specialized cameras include multispectral imaging equipment and astrographs used for scientific, military, medical and other purposes.
Compacts
The compact camera is meant to be portable and is perfect for regular "photos".
Many incorporate retractable lens assemblies that provide optical zoom. In most models, automatic lens caps protect the lens of the elements. Most waterproof or ruggedized models do not pull back, and most with superzoom capabilities do not pull completely.
Pocket cameras are usually designed to be easy to use. Almost all include automatic mode, or "auto mode", which automatically sets up all camera settings for the user. Some also have manual controls. Compact digital cameras typically contain small sensors that trade image quality for compactness and simplicity; images can usually only be stored using lossy compression (JPEG). Most have built-in flash usually with low power, enough for the nearest subject. Some high end compact digital cameras have a hotshoe to connect to an external flash. Direct previews are almost always used to frame photos on an integrated LCD. In addition to taking still photos almost all pocket cameras have the ability to record video.
Compact often have macro capability and zoom lens, but zoom range (up to 30x) is generally enough for candid photography but less than available on bridge camera (more than 60x), or replacement DSLR camera lens available in much higher place. cost. Autofocus systems in compact digital cameras are generally based on contrast detection methodologies using image data from feed previews directly from the main imager. Some compact digital cameras use a hybrid autofocus system similar to what is commonly available in DSLRs.
Typically, a compact digital camera incorporates a near-silent leaf shutter to the lens but plays simulated camera sounds for skeuomorphic purposes.
For low cost and small size, these cameras typically use a picture sensor format with diagonals between 6 and 11 mm, corresponding to a crop factor between 7 and 4. This gives them a weaker low light performance, greater field depth, more focus general capabilities, and smaller components of the camera using a larger sensor. Some cameras use larger sensors including, on high end, expensive full-frame compact cameras, such as the Sony Cyber-shot DSC-RX1, but have the ability to approach DSLRs.
Additional features are available depending on the camera model. These features include GPS, compass, barometer and altimeter.
Starting in 2011, some compact digital cameras can take 3D photos. This compact 3D stereo camera can capture 3D panoramic photos with a double lens or even a single lens to play on a 3D TV.
In 2013, Sony released two additional camera models without screens, for use with smartphones or tablets, controlled by mobile applications over WiFi.
Compact abrasive
Rugged compact cameras usually include protection against immersion, hot and cold conditions, shocks and pressure. Terms used to describe such properties include waterproof, waterproof, heat resistance, shockproof and crushproof, respectively. Almost all major camera manufacturers have at least one product in this category. Some are waterproof to a depth of up to 82 feet (27 m); others are only 10 feet (3m), but only a few will float. Ruggeds often lack some of the usual pocket camera features, but they have video capabilities and the majority can record sound. Most have image stabilization and built-in flash. Touchscreen LCD and GPS do not work under water.
Action camera
GoPro and other brands offer rugged, small and actionable cameras mounted on helmets, arms, bicycles, etc. Most have wide-angle and fixed focus, and can take still images and video, usually with sound.
The increasing popularity of action cameras is in line with many people who want to share photos or videos on social media. Many competitive action camera manufacturers produce many options and lower competitive prices, and nowadays, cameras are sold with waterproof homes, accessories, and buffers that are compatible with popular GoPro.
360 degree camera
The 360-degree camera can take pictures or 360-degree video using two back-to-back lenses and take pictures at the same time. Some cameras are Ricoh Theta S, Nikon Keymission 360 and Samsung Gear 360. Nico360 is launched in 2016 and is claimed to be the smallest 360 degree camera in the world with size 46 x 46 x 28 mm (1.8 x 1.8 x 1.1 in ) and the price is less than $ 200. With virtual reality mode built-in stitching, Wifi, and Bluetooth, live streaming can be done. Because it's also waterproof, Nico360 can be used as an action camera.
There is a tendency that action cameras have the ability to shoot 360 degrees with a resolution of at least 4K.
Camera bridge
The bridge cameras physically resemble a DSLR, and are sometimes called DSLR-shaped or DSLR-like. They provide some similar features but, like compacts, they use fixed lenses and small sensors. Some pocket cameras also have PSAM mode. Most use direct previews to frame images. Their usual autofocus is by the same contrast-detection mechanism with compacts, but many bridge cameras have manual focus mode and some have separate focus rings for larger controls.
Large physical size and small sensors allow superzoom and wide aperture. Bridgcams generally include image stabilization systems to allow longer handheld exposure, sometimes better than DSLRs for low light conditions.
In 2014, bridge cameras come in two main classes in terms of sensor size, first more traditional 1/2 "sensors (measured by image sensor format) that provide more flexibility in lens design and enable a holding zoom of 20 to 24mm (35mm equivalent) wide angle all the way up to more than 1000 mm of supertele, and both 1 "sensors that allow better image quality especially in low light (higher ISO) but place a greater constraint on the lens design, resulting in a zoom lens stops at 200mm (constant aperture, eg Sony RX10) or 400mm (variable openings, eg Panasonic Lumix FZ1000) equivalent, corresponding to the optical zoom factor of about 10 to 15.
Some bridge cameras have lens threads to install accessories such as wide-angle or telephoto converters as well as filters such as UV filters or Circular Polarizing and lens hoods. The scene is composed by viewing the screen or the electronic viewfinder (EVF). Most have slightly longer shutter lags than DSLRs. Many of these cameras can store images in raw format in addition to supporting JPEG. The majority have built-in flash, but few have hotshoe.
In bright sunlight, the difference in quality between a good pocket camera and minimal digital SLR but a bridge camera is more portable, less expensive and has greater zoom capability. So the bridge camera may be more suited to outdoor daytime activities, except when looking for professional quality photos.
Camera without lens-changing mirrors
In late 2008, a new type of camera emerged called a mirrorless interchangeable-lens camera (MILC), which uses multiple sensors and offers interchangeability of the lens. It's simpler and more compact than a DSLR because it does not have a lens reflex system. The MILC camera models are available with a variety of sensor sizes including: 1/2.3 inch small sensors, such as those used in bridge cameras like the original Pentax Q (the newer Pentax Q version has a slightly larger 1/1.7 inch sensor); 1 inch sensor; Micro Four Thirds sensors; APS-C sensors such as the Sony NEX series, Fujifilm X series, Pentax K-01, and Canon EOS M; and some, like the Sony 7, use the full frame sensor (35 mm) and even the Hasselblad X1D is the first MILC medium format. Some MILC cameras have separate electronic viewfinder. In another camera, the back screen is used as a viewfinder in the same way as a pocket camera. The shortcomings of MILC compared to DSLR are the battery life due to the energy consumption of the electronic viewfinder.
Olympus and Panasonic released many Micro Four Thirds cameras with replaceable lenses that are fully compatible with each other without an adapter, while others have proprietary mounts. In 2014, Kodak released the first Micro Four Third system camera.
As of March 2014, MILC cameras are available that appeal to amateurs and professionals.
Camera modular
While most digital cameras with interchangeable lenses have a kind of lens mount, there are also a number of modular cameras, where shutter and sensor are inserted into the lens module.
The first modular camera was Minolta DimÃÆ'Â V Ge in 1996, followed by Minolta DimÃÆ'Â ¢ ge EX 1500 in 1998 and Minolta MetaFlash 3D 1500 in 1999. In 2009, Ricoh released a modular Ricoh GXR camera.
At CES 2013, Sakar International announces the Polaroid iM1836, an 18 MP camera with a 1 "sensor with replaceable sensors Adapters for Micro Four Thirds, Nikon and K-mount lenses are planned to ship with cameras.
There are also a number of camera add-on modules for smartphones called lens-style cameras (camera lenses). They contain all the digital camera components in the module, but do not have a viewfinder, screen and most controls. Instead they can be plugged into a smartphone and use the screen and its controls. The lens-style camera includes:
- Sony SmartShot QX series, announced and released in mid-2013. In January 2014 announced firmware updates for Cyber-shot SmartShot DSC-QX10 and DSC-QX100. In September 2014, Sony announced the Cyber-shot SmartShot DSC-QX30 as well? SmartShot ILCE-QX1, the latter with E-mount instead of a built-in lens.
- Kodak PixPro smart lens camera series, announced in 2014.
- The Vivicam smart lens camera series from Vivitar/Sakar, announced in 2014.
- Olympus Air camera lens, announced in 2014 and released in 2015, the lens camera is an open platform using Android (operating system) and can be released into 2 parts (sensor parts and lens parts) and all Micro Four Thirds Lens lenses can be attached to the lens sensor portion of the lens.
One-lens digital reflector camera
The digital single lens reflector camera (DSLR) uses a reflective mirror that can reflect light and can also rotate from one position to another and return to its original position. By default, the reflex mirror is set 45 degrees from the horizontal, blocking the light to the sensor and reflecting light from the lens to the penta-mirror/prism on the DSLR camera and after some reflection arrives in the viewfinder. The reflex mirror is pulled out horizontally beneath the penta/prism when the shutter release is fully pressed, so the viewfinder will darken and the light/image can directly attack the sensor at the time of lighting (speed setting).
Autofocus is achieved using sensors in the mirror box. Some DSLRs have a "live view" mode that allows framing using the screen with images from the sensor.
This camera has a sensor that is much larger than other types, usually 18 mm to 36 mm on the diagonal (crop factor 2, 1.6, or 1). Larger sensors allow more light to be received by each pixel; this, combined with a relatively large lens provides superior low-light performance. For the same field of view and the same aperture, larger sensors provide a more shallow focus. They use interchangeable lenses for versatility. Usually some lenses are made only for the use of digital SLRs, but the latest lens trends can also be used in detachable lens video cameras with or without adapters.
Digital Single Lens Translucent (DSLT) camera
DSLT uses a translucent fixed mirror instead of the movable reflex as in a DSLR. Transparent mirror or transmissive mirror or semi-transparent mirror is a mirror that reflects light into two objects at the same time. It reflects along the path to the pentaprism/pentamirror which then goes to the optical view finder (OVF) as it does with a reflex mirror in a DSLR camera. The translucent mirror also transmits light along the second line to the sensor. The total amount of light does not change, only part of the light travels one path and some moves in the other direction. The consequence is that DSLT cameras have to shoot a half-stop different from DSL. One of the advantages of using DSLT cameras is the blind moments that DSLR users experience when the reflective mirror is moved to send light to the sensor instead of the viewfinder that is not available for DSLT cameras. Since there is no time in which light does not run on either path, DSLT cameras benefit from continuous auto focus tracking. This is very useful for shooting burst mode in dim light conditions and also for tracking while taking video.
Until early 2014, only Sony has released a DSLT camera. In March 2013, Sony has released more DSLT than DSLR with a relatively complete lens.
Digital distance meter
Spies are devices for measuring subject distance, with a view to adjusting the focus of the corresponding camera's objective lens (open-loop controller). Spies and lens focus mechanisms may or may not be combined. In common language, the term "surveillance camera" is interpreted as very narrow to show a manual focus camera with optical readers that are read visually based on parallax. Most digital cameras achieve focus through image analysis captured by the objective lens and distance estimation, if provided at all, are merely byproducts of the focusing process (closed-loop control).
Line scanner camera system
Line-scan cameras traditionally have one line of pixel sensors, not matrices of them. Continuous lines are fed to computers that connect them to each other and create images. This is most often done by connecting the camera output to the frame grabber that is in the PCI slot of an industrial computer. The grabber frame serves to support the image and sometimes provides some processing before it is sent to the computer software for processing.
Some sensor lines can be used to create color images, or to increase sensitivity by TDI (Delay and integration).
Many industrial applications require a wide field of view. Traditionally maintaining consistent light over a large 2D area is quite difficult. With the necessary camera scan lines it is to provide even the entire "line" lighting currently viewed by the camera. This allows sharp images of objects that pass through the camera at high speed.
Cameras like this are also commonly used to create finished photos, to determine the winner when multiple competitors cross the finish line at about the same time. They can also be used as an industrial instrument to analyze rapid processes.
Linescan cameras are also widely used in imaging of satellites (see scanner sweep). In this case a series of sensors perpendicular to the direction of satellite motion. Linescan cameras are widely used in scanners. In this case, the camera moves horizontally.
Stand-alone camera
Stand-alone cameras can be used as remote cameras. One type of weight is 2.31 ounces (65.5 g), with a periscope shape, IPx7 is waterproof and rated dustproof and can be upgraded to IPx8 using a cap. They do not have a viewfinder or LCD. The lens is a 146 degree wide angle or standard lens, with fixed focus. It can have a microphone and speakers, and can take photos and videos. As a remote camera, phone apps using Android or iOS are required to send live video, change settings, take photos, or use time lapses.
Integration to other devices
Many devices have built-in digital cameras, including, for example, smartphones, mobile phones, PDAs, and laptop computers. The built-in camera generally stores images in JPEG file format.
Mobile phones that incorporate digital cameras were introduced in Japan in 2001 by J-Phone. In 2003 the camera phones went beyond stand-alone digital cameras, and in 2006 they sold more self-contained movies and digital cameras. Five billion camera phones were sold in five years, and in 2007 more than half of the phone bases installed in all phones were camera phones. Separate camera sales peaked in 2008.
Market trends
The sale of traditional digital cameras has declined due to the increasing use of smartphones for casual photography, which also allows easier manipulation and photo sharing through the use of web-based applications and services. The "bridge camera", by contrast, has retained its foundation with functions that most smart phone cameras do not have, such as optical zoom and other advanced features. DSLRs have also been lost to mirrorless interchangeable-lens (MILC) cameras that offer the same sensor size in smaller cameras. Some are expensive using full-frame sensors as professional DSLR cameras.
In response to the convenience and versatility of smart phone cameras, some manufacturers produce "smart" digital cameras that combine traditional camera features with smart phone cameras. In 2012, Nikon and Samsung released Coolpix S800c and Galaxy Camera, the first two digital cameras running the Android operating system. Since these software platforms are used on many smart phones, they can integrate with services (such as email attachments, social networking and photo sharing sites) just like smartphones, and using other software that is also compatible with Android.
In inversion, several mobile phone makers have introduced smartphones with cameras designed to resemble traditional digital cameras. Nokia releases 808 PureView and Lumia 1020 in 2012 and 2013; both devices run their respective Symbian and Windows Phone operating systems, and both include 41-megapixel cameras (along with camera grip attachments for the latter). Similarly, Samsung introduced the Galaxy S4 Zoom, has a 16-megapixel camera and 10x optical zoom, combining the properties of the Galaxy S4 Mini with Galaxy Camera. In addition, the Panasonic Lumic DMC-CM1 is an Android smartphone KitKat 4.4 with 20MP sensor, 1 ", the largest sensor for smartphone ever, with fixed lens Leica equivalent to 28mm on F2.8, can take RAW and 4K video, have 21mm thickness.
The light-field camera was introduced in 2013 with one consumer product and several professional products.
After a sharp decline in sales in 2012, sales of consumer digital cameras declined again in 2013 by 36 percent. In 2011, the compact digital camera sold 10 million per month. In 2013, sales dropped to about 4 million per month. DSLR and MILC sales also declined in 2013 by 10-15% after nearly two decades of double-digit growth. Worldwide sales of digital camera units continue to decline from 148 million in 2011 to 58 million by 2015 and tend to decline more in the following years.
The film camera sold peaked at 36,671 million units in 1997 and digital cameras sold starting in 1999. In 2008, the film camera market has died and digital cameras sold peaked at 121,463 million units in 2010. In 2002, mobile phones with cameras have been introduced and in 2003 mobile phones with cameras sold 80 million units per year. In 2011 phones with cameras sold hundreds of millions per year, when the digital cameras being sold were initialized to decline. By 2015, digital cameras sold are 35,395,000 units or just less than a third of the number of digital cameras sold at the top and also slightly less than the number of film cameras sold at the top.
Connectivity
Transfer photos
Many digital cameras can connect directly to a computer to transfer data: -
- The initial camera uses the PC serial port. USB is now the most widely used method (most cameras can be viewed as USB mass storage), though some have FireWire ports. Some cameras use USB PTP mode for connection, not MSC USB; some offer both modes.
- Another camera uses a wireless connection, via Bluetooth or IEEE 802.11 Wi-Fi, such as Kodak EasyShare One. Integrated Wi-Fi Memory Card (SDHC, SDXC) can send images, videos and other files saved to a computer or smartphone. Mobile operating systems like Android allow automatic uploading and backing up or sharing images over Wi-Fi to share photos and cloud services.
- Cameras with integrated Wi-Fi or certain Wi-Fi adapters allow for camera control, in particular shutter release, lighting control, and more (tethering) of computer applications or smartphones than media data transfers.
- Video cameras and some sophisticated stand-alone digital cameras also use cellular networks to connect to share images. The most common standard on mobile networks is the MMS Multimedia Messaging Service, commonly called "picture messaging". The second method with smartphones is to send images as email attachments. Many old kameraphones, however, do not support email.
A common alternative is the use of card readers that may be able to read several types of storage media, as well as high-speed data transfer to a computer. The use of card readers also avoids draining the camera battery during downloading. The external card reader allows convenient direct access to images on a collection of storage media. But if only one storage card is used, moving it back and forth between the camera and the reader can be inconvenient. Many computers have card readers installed, at least for SD cards.
Print photos
Many modern cameras support PictBridge standard, which lets them send data directly to a PictBridge-enabled computer printer without the need for a computer.
Wireless connectivity can also provide for printing photos without a wired connection.
Camera instant-printing , is a digital camera with an internal printer. It bestows a similar functionality as an instant camera that uses instant movies to produce physical images quickly. The non-digital camera was popularized by Polaroid in 1972.
View photos
Many digital cameras include video output ports. Usually sVideo, it sends standard definition video signals to the television, allowing the user to display one image at a time. The camera button or menu allows users to select photos, forward from one to the other, or automatically send "slide shows" to the TV.
HDMI has been adopted by many high-end digital camera makers, to display photos in high-resolution quality on HDTV.
In January 2008, Silicon Image announced a new technology for sending video from mobile devices to television in digital form. MHL sends the image as a video stream, up to 1080p resolution, and is compatible with HDMI.
Some DVD recorders and television sets can read the memory cards used in the camera; Some alternative types of flash card readers have TV output capabilities.
Weather and anti-air sealing
The camera can be equipped with a variety of environmental sealing sizes to provide protection against water spray, moisture (moisture and mist), dust and sand, or complete water resistance to a certain depth and for a certain duration. The latter is one approach to enabling underwater photography, another approach is the use of home waterproof. Many waterproof digital cameras are also shock resistant and resistant to low temperatures.
Mode
Many digital cameras have preset modes for various applications. Within the correct exposure limits, various parameters can be changed, including lighting, exposure, focus, light measurement, white balance, and equivalent sensitivity. For example, portraits may use a wider aperture to make the background unfocused, and will search and focus on the human face than any other image content.
Image data storage
Many of the most stand-alone camera phones and digital cameras store image data on flash memory cards or other external media. Most stand-alone cameras use SD format, while some use CompactFlash or other types. In January 2012, a faster XQD card format was announced. As early as 2014, some high-end cameras have two swapable memory slots. Photographers can exchange one memory card with the camera-on. Each memory slot can accept Compact Flash or SD Card. All new Sony cameras also have two memory slots, one for Memory Stick and another for SD Card, but not heat exchanged.
Some cameras use other removable storage such as Microdrives (very small hard disk drives), single CDs (185 MB), and 3.5-inch floppy disks. Other unusual formats include:
- Onboard flash memory - Secondary cheap camera and camera for main device usage (such as camera phone)
- PC Card hard drive - early professional camera (not resumed)
- Thermal printer - known only in one camera model that prints images immediately rather than saving
Most digital camera manufacturers do not provide drivers and software to allow their cameras to work with Linux or other free software. However, many cameras use standard USB storage protocols, and are thus easy to use. Another camera is supported by the gPhoto project.
File format
Standard Joint Photography Experts Group (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 raw image formats. A raw image is a collection of pixel data that is not processed directly from the camera sensor, often stored in proprietary format. Adobe Systems has released the DNG format, a royalty-free raw image format used by at least 10 camera manufacturers.
Raw files must initially be processed in special image editing programs, but over time many major editing programs, such as Google Picasa, have added support for raw images. Rendering to standard images from raw sensor data allows more flexibility in making large adjustments without losing image quality or recapturing images.
The formats for movies are AVI, DV, MPEG, MOV (often containing JPEG motion), WMV, and ASF (basically the same as WMV). The latest formats include MP4, which is based on the QuickTime format and uses newer compression algorithms to allow longer recording time in the same space.
Another format used in the camera (but not for images) is the Design Rules for Camera Format (DCF), the ISO specification, used on almost all cameras since 1998, which defines the structure and naming of internal files. Also used is the Digital Print Order Format (DPOF), which determines what order image to print and how many copies. The DCF 1998 defines a logical file system with 8.3 filenames and makes use of FAT12, FAT16, FAT32 or exFAT mandatory for its physical layer to maximize platform interoperability.
Most cameras include Exif data that provides metadata about images. Exif data may include aperture, lighting time, focal length, date and time taken, and location.
Battery
Digital cameras have become smaller over time, producing a sustainable need to develop batteries that are small enough to fit on the camera and have not been able to turn it on for a reasonable period of time.
Digital cameras use proprietary or standard consumer batteries. As of March 2014, most cameras use exclusive lithium-ion batteries while some use standard AA batteries or primarily use rechargeable Lithium-ion batteries but have optional AA batteries available.
Ownership
The most common battery class used in digital cameras is the exclusive battery format. These are built to manufacturer specifications. Almost all proprietary batteries are lithium-ion. In addition to being available from OEMs, aftermarket replacement batteries are generally available for most camera models.
Standard consumer battery
Digital cameras that use off-shelf batteries are usually designed to be able to use disposable and rechargeable batteries, but not with both types used at the same time. The most commonly used off-the-shelf battery size is AA. CR2, CR-V3, and AAA batteries are also used in some cameras. CR2 and CR-V3-based lithium batteries, intended for single use. Rech-V3 rechargeable lithium-ion batteries are also available as an alternative to non-rechargeable CR-V3 batteries.
Some of the battery grips for DSLR come with separate holders to accommodate AA cells as an external power source.
Convert film camera to digital
When digital cameras become common, many photographers ask if their movie cameras can be converted to digital. The answer is yes and no. For most 35mm film cameras the answer is no, rework and the cost is too great, especially since the lens has evolved as well as the camera. For most of the conversion to digital, to provide enough space for electronics and enable the display of liquid crystals for preview, it will require removing the back of the camera and replacing it with a custom made digital unit.
Many early professional SLR cameras, such as the Kodak DCS series, were developed from 35 mm film cameras. Time technology, however, means that instead of digital "backs", these camera bodies are mounted on large and large digital units, often larger than the camera parts themselves. This is a factory-made camera, however, not an aftermarket conversion.
The key exceptions are Nikon E2 and Nikon E3, using an additional optical to convert 35mm format to 2/3 CCD-sensor.
Some 35mm cameras have digital camera backs made by their manufacturers, Leica is a noteworthy example. Medium and large format camera formats (which use film stocks over 35 mm), have low unit production, and typical digital backs for more than $ 10,000. These cameras also tend to be very modular, with handrails, backs of films, winders, and lenses available separately to meet various needs.
The enormous sensor that this back uses leads to a very large image size. For example, the image P45 39Ã, MP Stage One re-creates a single TIFF image with sizes up to 224.6 MB, and even larger numbers of pixels are also available. Such medium format digitals are more directed to studio photography and portraits than their smaller DSLR counterparts; ISO speeds in particular tend to have a maximum of 400, compared to 6400 for some DSLR cameras. (Canon EOS-1D Mark IV and Nikon D3S have ISO 12800 plus Hi-3 ISO 102400 with ISO Canon EOS-1Dx 204800)
Digital camera backs
In the professional and high-end industry photography market, some camera systems use modular image sensors (moveable). For example, some medium format SLR cameras, such as the Mamiya 645D series, allow for the re-installation of a traditional digital camera or photographic film.
- Array Area
- CCD
- CMOS
- Linear array
- CCD (monochrome)
- 3-way CCD with color filter
Linear array cameras are also called back scans.
- One shot
- Multi-shot (three-shot, usually)
Most of the backs of previous digital cameras use linear array sensors, moving vertically to digitize images. Many of them only capture grayscale images. A relatively long exposure time, within seconds or even minutes generally limits the scanning back to the studio application, where all aspects of the photographic scene are under the control of the photographer.
Some rear cameras use CCD arrays that are similar to regular cameras. This is called a one-shot back.
Because it is much easier to create high-quality linear CCD lines with only thousands of pixels rather than CCD matrices with millions, the very high resolution of linear CCD cameras available back much earlier than their CCD matrix counterparts. For example, you can buy a (though expensive) camera back with a horizontal resolution of 7,000 pixels in the mid-1990s. However, in 2004, it was still difficult to buy a CCD matrix camera proportional to the same resolution. Playing a line camera, with about 10,000 pixels of color on its sensor line, was able, in 2005, to capture about 120,000 lines during a full 360 degree rotation, thus creating a single 1,200 Megapixel digital image.
Most modern digital cameras use CCD or CMOS matrix sensors. The matrix sensor captures the entire picture frame at once, rather than adding to the frame area scanning through the old exposure. For example, Phase One produces 39 million pixels of digital cameras back with 49.1 x 36.8 mm CCDs in 2008. This CCD array is slightly smaller than a 120-film frame and much larger than a 35 mm (36 x 24 mm) frame). For comparison, consumer digital cameras use arrays ranging from 36 x 24 mm (full frame on high end consumer DSLRs) up to 1.28 x 0.96 mm (on camera phones) CMOS sensors.
See also
- Image stabilization
- Smart camera
- Digital video camera
- Digital signal processor
- Vision processing unit
References
External links
- History of digital cameras and digital imaging, Digital Camera Museum
- Digital camera in EncyclopÃÆ'Â|dia Britannica
Source of the article : Wikipedia
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