Digital camera

[6][7] The first semiconductor image sensor was the charge-coupled device (CCD), invented by Willard S. Boyle and George E. Smith at Bell Labs in 1969,[8] based on MOS capacitor technology.

The MSS, designed by Virginia Norwood at Hughes Aircraft Company starting in 1969, captured and transmitted image data from green, red, and two infrared bands with 6 bits per channel, using a mechanical rocking mirror and an array of 24 detectors.

CCD sensors were not yet commercially available, and the camera used a silicon diode vidicon tube detector, which was cooled using dry ice to reduce dark current, allowing exposure times of up to one hour.

[16] Steven Sasson, an engineer at Eastman Kodak, built a self-contained electronic camera that used a monochrome Fairchild CCD image sensor in 1975.

[22] The Mavica electronic still camera recorded FM-modulated analog video signals on a newly developed 2" magnetic floppy disk, dubbed the "Mavipak".

It employed an SLR viewfinder, included a 2/3" format color CCD sensor with 380K pixels, and was sold along with a removable 11-66mm and 50-150mm zoom lens.

Depending on the physical structure of the sensor, a color filter array may be used, which requires demosaicing to recreate a full-color image.

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

Depending on the physical structure of the sensor, a color filter array may be used, which requires demosaicing to recreate a full-color image.

For low cost and small size, these cameras typically use image sensor formats with a diagonal between 6 and 11 mm, corresponding to a crop factor between 7 and 4.

This gives them weaker low-light performance, greater depth of field, generally closer focusing ability, and smaller components than cameras using larger sensors.

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

[46] Rugged compact cameras typically include protection against submersion, hot and cold conditions, shock, and pressure.

Bridge cameras generally include an image stabilization system to enable longer handheld exposures, sometimes better than DSLR for low light conditions.

Olympus and Panasonic released many Micro Four Thirds cameras with interchangeable lenses that are fully compatible with each other without any adapter, while others have proprietary mounts.

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

[63] When the shutter release is fully pressed the reflex mirror pulls out horizontally below the pentaprism briefly darkening the viewfinder and then opening up the sensor for exposure which creates the photo.

Many modern DSLRs offer the ability for "live view" or the framing of the subject emitted from the sensor onto a digital screen, and many have a hotshoe.

[63] The larger sensor permits more light to be received by each pixel; this, combined with the relatively large lenses provides superior low-light performance.

[citation needed] A rangefinder is a device to measure subject distance, with the intent to adjust the focus of a camera's objective lens accordingly (open-loop controller).

Sales of traditional digital cameras have declined due to the increasing use of smartphones for casual photography, which also enable easier manipulation and sharing of photos through the use of apps and web-based services.

A common alternative is the use of a card reader which may be capable of reading several types of storage media, as well as high speed transfer of data to the computer.

Many modern cameras support the PictBridge standard, which allows them to send data directly to a PictBridge-capable printer without the need for a computer.

Buttons or menus on the camera allow the user to select the photo, advance from one to another, or automatically send a "slide show" to the TV.

Cameras can be equipped with a varying amount of environmental sealing to provide protection against splashing water, moisture (humidity and fog), dust and sand, or complete waterproofness to a certain depth and for a certain duration.

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

[clarification needed] Still, many cameras use the standard USB mass storage and/or Media Transfer Protocol, and are thus widely supported.

The Joint Photography Experts Group standard (JPEG) is the most common file format for storing image data.

The DCF 1998 defines a logical file system with 8.3 filenames and makes the usage of either FAT12, FAT16, FAT32 or exFAT mandatory for its physical layer in order to maximize platform interoperability.

[97] To enable loading many images in miniature view quickly and efficiently, and to retain meta data, some vendors' firmwares generate accompanying low-resolution thumbnail files for videos and raw photos.