2. History
• Steven Sasson as an engineer at Eastman
Kodak invented and built the first electronic
camera using a charge-coupled device image
sensor in 1975. Earlier ones used a camera
tube; later ones digitized the signal.
3. Definiton
• A digital still camera is a camera that
encodes digital images and videos
digitally and stores them for later
reproduction.
• Digital and film cameras share an optical
system, typically using a lens with a
variable diaphragm to focus light onto an
image pickup device.
4. Image sensors
• The resolution of a digital camera is often limited by the
image sensor (typically a CCD or CMOS sensor chip) that turns
light into discrete signals
• The brighter the image at a given point on the sensor, the
larger the value that is read for that pixel.
• single-shot capture systems use either one sensor chip with
a Bayer filter mosaic, or three separate image sensors
• multi-shot exposes the sensor to the image in a sequence of
three or more openings of the lens aperture.
• The third method is called scanning because the sensor
moves across the focal plane much like the sensor of an image
scanner.
5. Types of digital cameras
Digital compact cameras
• Compact cameras are intended to be portable
and are particularly suitable for casual
"snapshot".
• Most, apart from ruggedized or waterresistant models, incorporate a retractable
lens assembly that provides optical zoom. The
auto actuating lens cover protects the lens
from elements.
6. Types of digital cameras
Bridge cameras
• Bridge are higher-end digital cameras that
physically resemble DSLRs and share with
them some advanced features, but share with
compacts the use of a fixed lens and a small
sensor.
• Like compacts, most use live preview to frame
the image.
• Their autofocus uses the same contrast-detect
mechanism, but many bridge cameras have
a manual focus mode, in some cases using a
separate focus ring, for greater control
.
7. Types of digital cameras
Mirrorless interchangeable-lens camera
• In late 2008, a new type of camera
emerged, which uses larger sensors and offers
lens interchangeability.
• These are simpler and more compact than
DSLRs as they do not have the lens reflex
system.
8. Types of digital cameras
Digital single lens reflex cameras
• Digital single-lens reflex cameras (DSLR) uses
mirror to direct light from the lens through a
separate optical viewfinder.
• The mirror is moved out of the way to direct
the image to the sensor at the time of
exposure.
9. Connectivity
• Many digital cameras can connect directly to a
computer to transfer data.
• Many modern cameras support the PictBridge
standard, which allows them to send data directly
to a PictBridge-capable computer printer without
the need for a computer.
• Many digital cameras include a video output port.
Usually sVideo, it sends a standard-definition
video signal to a television, allowing the user to
show one picture at a time.
10. Image data storage
• Many camera phones and most stand alone digital
cameras use removable flash memory card to store
image data. The majority of cards for separate cameras
are SD format.
• Onboard flash memory — Cheap cameras and cameras
secondary to the device's main use (such as a camera
phone)
• PC Card hard drives — early professional cameras
(discontinued)
• Thermal printer — known only in one model of camera
that printed images immediately rather than storing
11. Batteries
• Digital cameras have become smaller over
time, resulting in an ongoing need to develop
a battery small enough to fit in the camera
and yet able to power it for a reasonable
length of time.
• Digital cameras utilize either proprietary or
standard consumer batteries.
12. File formats
• The Joint Photography Experts Group standard (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 a raw
image format. A raw image is the unprocessed set of
pixel data directly from the camera's sensor, often
saved in a proprietary format. Adobe Systems has
released the DNG format, a royalty-free raw image
format used by at least 10 camera manufacturers.
