A digital camera (or digicam for short) is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor.
Front and back of a Canon PowerShot A95.

Many compact digital still cameras can record sound and moving video as well as still photographs. In the Western market, digital cameras outsell their 35 mm film counterparts.

Digital cameras can do things film cameras cannot: displaying images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, recording video with sound, and deleting images to free storage space. Some can crop pictures and perform other elementary image editing. Fundamentally they operate in the same manner as film cameras, typically using a lens with a variable diaphragm to focus light onto an image pickup device. The combination of the diaphragm and a shutter mechanism is used to admit the correct amount of light to the imager, just as with film; the only difference is that the image pickup device is electronic rather than chemical.

Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialised digital cameras.

Wednesday, October 28, 2009

Canon Ixus 100 IS / Powershot SD780 IS

Canon Ixus 100 IS / Powershot SD780 IS
It may be the slimmest Digital ELPH Canon has ever created, but the impact couldn’t be bigger. The PowerShot SD780 IS Digital ELPH captivates the senses with bold saturated colors and a daringly original design that matches the intensity of Canon’s most innovative camera technology. Even when picture-taking conditions seem pretty unforgiving, you’ve got Canon on your side. So the shots you used to miss are the images you’ll now be sharing, and the movies you never too…


Specifications

  • Format
    Ultra Compact
  • Max resolution
    4000 x 3000
  • Low resolution
    4000 x 2248, 3264 x 2448, 2592 x 1944, 1600 x 1200, 640 x 480, 320 x 140
  • Image ratio w:h
    4:3,16:9
  • Effective pixels
    12.1 million
  • Sensor size
    1/2.3 " (6.16 x 4.62 mm, 0.28 cm²)
  • Pixel density
    43 MP/cm²
  • Sensor type
    CCD
  • ISO rating
    Auto, 80 ,100, 200, 400, 800, 1600
  • Zoom wide (W)
    33 mm

Release Date

  • First seen 9 February 2009

The arrival of true digital cameras





The first true digital camera that recorded images as a computerized file was likely the Fuji DS-1P of 1988, which recorded to a 16 MB internal memory card that used a battery to keep the data in memory. This camera was never marketed in the United States, and has not been confirmed to have shipped even in Japan.

The first commercially available digital camera was the 1990 Dycam Model 1; it also sold as the Logitech Fotoman. It used a CCD image sensor, stored pictures digitally, and connected directly to a computer for download.

In 1991, Kodak brought to market the Kodak DCS-100, the beginning of a long line of professional Kodak DCS SLR cameras that were based in part on film bodies, often Nikons. It used a 1.3 megapixel sensor and was priced at $13,000.

The move to digital formats was helped by the formation of the first JPEG and MPEG standards in 1988, which allowed image and video files to be compressed for storage. The first consumer camera with a liquid crystal display on the back was the Casio QV-10 in 1995, and the first camera to use CompactFlash was the Kodak DC-25 in 1996.

The marketplace for consumer digital cameras was originally low resolution (either analog or digital) cameras built for utility. In 1997 the first megapixel cameras for consumers were marketed. The first camera that offered the ability to record video clips may have been the Ricoh RDC-1 in 1995.

1999 saw the introduction of the Nikon D1, a 2.74 megapixel camera that was the first digital SLR developed entirely by a major manufacturer, and at a cost of under $6,000 at introduction was affordable by professional photographers and high end consumers. This camera also used Nikon F-mount lenses, which meant film photographers could use many of the same lenses they already owned.

Analog electronic cameras

Handheld electronic cameras, in the sense of a device meant to be carried and used like a handheld film camera, appeared in 1981 with the demonstration of the Sony Mavica (Magnetic Video Camera). This is not to be confused with the later cameras by Sony that also bore the Mavica name. This was an analog camera, in that it recorded pixel signals continuously, as videotape machines did, without converting them to discrete levels; it recorded television-like signals to a 2 × 2 inch "video floppy". In essence it was a video movie camera that recorded single frames, 50 per disk in field mode and 25 per disk in frame mode. The image quality was considered equal to that of then-current televisions.

Analog electronic cameras do not appear to have reached the market until 1986 with the Canon RC-701. Canon demonstrated a prototype of this model at the 1984 Summer Olympics, printing the images in the Yomiuri Shimbun, a Japanese newspaper. In the United States, the first publication to use these cameras for real reportage was USA Today, in its coverage of World Series baseball. Several factors held back the widespread adoption of analog cameras; the cost (upwards of $20,000), poor image quality compared to film, and the lack of quality affordable printers. Capturing and printing an image originally required access to equipment such as a frame grabber, which was beyond the reach of the average consumer. The "video floppy" disks later had several reader devices available for viewing on a screen, but were never standardized as a computer drive.

The early adopters tended to be in the news media, where the cost was negated by the utility and the ability to transmit images by telephone lines. The poor image quality was offset by the low resolution of newspaper graphics. This capability to transmit images without a satellite link was useful during the Tiananmen Square protests of 1989 and the first Gulf War in 1991.

US government agencies also took a strong interest in the still video concept, notably the US Navy for use as a real time air-to-sea surveillance system.

The first analog camera marketed to consumers may have been the Canon RC-250 Xapshot in 1988. A notable analog camera produced the same year was the Nikon QV-1000C, designed as a press camera and not offered for sale to general users, which sold only a few hundred units. It recorded images in greyscale, and the quality in newspaper print was equal to film cameras. In appearance it closely resembled a modern digital single-lens reflex camera. Images were stored on video floppy disks.

History

Early development

The concept of digitizing images on scanners, and the concept of digitizing video signals, predate the concept of making still pictures by digitizing signals from an array of discrete sensor elements. Eugene F. Lally of the Jet Propulsion Laboratory described a mosaic photosensor for use as a star sensor for measuring the altitude of a spacecraft at a 1961 space conference. At Philips Labs. in NY Edward Stupp, Pieter Cath and Zsolt Szilagyi filed for a patent on "All Solid State Radiation Imagers" on Sept. 6, 1968 and constructed a flat screen target for receiving and storing an optical image on a matrix composed of an array of photodiodes connected to a capacitor to form an array of two terminal devices connected in rows and columns. Their US patent was granted on Nov. 10, 1970. Texas Instruments engineer Willis Adcock designed a filmless camera and applied for a patent in 1972, but it is not known whether it was ever built. The first recorded attempt at building a digital camera was in 1975 by Steven Sasson, an engineer at Eastman Kodak. It used the then-new solid-state CCD image sensor chips developed by Fairchild Semiconductor in 1973. The camera weighed 8 pounds (3.6 kg), recorded black and white images to a cassette tape, had a resolution of 0.01 megapixels (10,000 pixels), and took 23 seconds to capture its first image in December 1975. The prototype camera was a technical exercise, not intended for production.

Conversion of film cameras to digital




When digital cameras became common, a question many photographers asked was whether their film cameras could be converted to digital. The answer was yes and no. For the majority of 35 mm film cameras the answer is no, the reworking and cost would be too great, especially as lenses have been evolving as well as cameras. For most a conversion to digital, to give enough space for the electronics and allow a liquid crystal display to preview, would require removing the back of the camera and replacing it with a custom built digital unit.

Many early professional SLR cameras, such as the NC2000 and the Kodak DCS series, were developed from 35 mm film cameras. The technology of the time, however, meant that rather than being a digital "backs" the bodies of these cameras were mounted on large, bulky digital units, often bigger than the camera portion itself. These were factory built cameras, however, not aftermarket conversions.

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

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

The very large sensor these backs use leads to enormous image sizes. The largest in early 2006 is the Phase One's P45 39 MP imageback, creating a single TIFF image of size up to 224.6 MB. Medium format digitals are geared more towards studio and portrait photography than their smaller DSLR counterparts; the ISO speed in particular tends to have a maximum of 400, versus 6400 for some DSLR cameras.

Integration

Many devices include digital cameras built into or integrated into them. For example, mobile phones often include digital cameras; those that do are sometimes known as camera phones. Other small electronic devices (especially those used for communication) such as PDAs, laptops and BlackBerry devices often contain an integral digital camera, as do some some digital camcorders.

Due to the limited storage capacity and general emphasis on convenience rather than image quality, the vast majority of these integrated or converged devices store images in the lossy but compact JPEG file format.

Mobile phones incorporating digital cameras were introduced in Japan in 2001 by J-Phone. In 2003 camera phones outsold stand-alone digital cameras, and in 2006 they outsold all film-based cameras and digital cameras combined. These camera phones reached a billion devices sold in only five years, and by 2007 more than half of the installed base of all mobile phones were camera phones.

Integrated cameras tend to be at the very lowest end of the scale of digital cameras in technical specifications, such as resolution, optical quality, and ability to use accessories. With rapid development, however, the gap between mainstream compact digital cameras and camera phones is closing, and high-end camera phones are competitive with low end stand-alone digital cameras of the same generation.

Line-scan camera systems

A line-scan camera is a camera device containing a line-scan image sensor chip, and a focusing mechanism. These cameras are almost solely used in industrial settings to capture an image of a constant stream of moving material. Unlike video cameras, line-scan cameras use a single array of pixel sensors, instead of a matrix of them. Data coming from the line-scan camera has a frequency, where the camera scans a line, waits, and repeats. The data coming from the line-scan camera is commonly processed by a computer, to collect the one-dimensional line data and to create a two-dimensional image. The collected two-dimensional image data is then processed by image-processing methods for industrial purposes.

Line-scan technology is capable of capturing data extremely fast, and at very high image resolutions. Usually under these conditions, resulting collected image data can quickly exceed 100 MB in a fraction of a second. Line-scan-camera–based integrated systems, therefore are usually designed to streamline the camera's output in order to meet the system's objective, using computer technology which is also affordable.

Line-scan cameras intended for the parcel handling industry can integrate adaptive focusing mechanisms to scan six sides of any rectangular parcel in focus, regardless of angle, and size. The resulting 2-D captured images could contain, but are not limited to 1D and 2D barcodes, address information, and any pattern that can be processed via image processing methods. Since the images are 2-D, they are also human-readable and can be viewable on a computer screen. Advanced integrated systems include video coding and optical character recognition