2. Digital photography that uses an array of light sensitive
sensors to capture the image focused by the lens,as
opposed an exposure on light sensitive film.The captured
image is then stored as a digital processing(colour
correction,sizing,cropping etc),viewing or printing.Until
the advent of such technology,photographs were made
by exposing light sensitive photo film,& used chemical
photographic processing to develop & stabilize the
image.By contrast,digital photographs can be
displayed,printed,stored,manipulated,transmited and
archived using digital and computer techniques ,without
chemical processing.
3. Advantages of professional digital
cameras
• Immegiate image review & deletion is possible,lighting &
composition can be assessed immediatily,which
ultimately conserves storage space.
• Faster workflow:Management(colour & file),manipulation
& printing tools are more versatile then convention film
processes.However,batch processing of RAW files can be
time consuming ,even on fast computer.
4. Disadvantages of digital
cameras
• Whereas film camerascan have manual backups for
electronic and electrical features, digital cameras are
entirely dependent on an electrical supply (usually
batteries but sometimes power cord when in 'tethered'
mode).
• Many digital sensors have less dynamic range than color
print film. However, some newer CCDs such as
Fuji's Super CCD, which combines diodes of different
sensitivity, have improved uWhen highlights burn out,
they burn to white without details, while film cameras
retain a reduced level of detail, as discussed aboveon
this issue.
5. Equivalent features
• Image noise / grainNoise in a digital camera's image is
remarkably similar to film grain in a film camera. At
high ISO levels (film speed) the grain/noise becomes more
apparent in the final image. Although film ISO levels can be
lower than digital ISO levels (25 and 50 respectively), digital
settings can be changed quickly according to requirements,
while film must be physically replaced and protected from all
light during such replacement. Additionally, image noise
reduction techniques can be used to remove noise from
digital images and film grain is fixed. From an artistic point of
view, film grain and image noise may be desirable when
creating a specific mood for an image. Modern digital cameras
have comparable noise/grain at the same ISO as film
cameras. Some digital cameras though, do exhibit a pattern in
the digital noise that is not found on film
6. Speed of use
• Previously digital cameras had a longer start-up delay
compared to film cameras, i.e., the delay from when they are
turned on until they are ready to take the first shot, but this is
no longer the case for modern digital cameras with start-up
times under 1/4 second (0.15 seconds for the Nikon
D90).[5] Similarly, the amount of time needed to write the
data for a digital picture to the memory card is now
comparable to the amount of time it takes to wind the film on
a film camera, at least with modern digital cameras and
modern fast memory cards.[citation needed] Both digital cameras
and film cameras have a small delay between when the
shutter button is pressed and when the picture is taken – this
is the time necessary to autofocus the lens and compute and
set the exposure. (This shutter delay is practically zero for
SLR and the best DSLR cameras.)
7. Frame rate
•
The Nikon D3 can take still photographs at 11 frames
per second; the fastest film SLR could shoot 14 frames
per second (Canon F1-n with a super high speed
motor, but fewer than 100 were constructed for the
1984 Summer Olympics[citation needed]). The Nikon F5 is
limited to 36 continuous frames (the length of the
film) while the Canon EOS-1D Mark III is able to take
about 110 high definition JPEG images before
its buffer must be cleared and the remaining space on
the storage media can be used. Even Bridge
camera such as Fujifilm FinePix HS10 has burst mode
10 frame/s and Panasonic Lumix DMC-FZ100 has 11
frame/s.[6][7] Moreover FinePix HS10 can take movies
at 1000 frame/s at 224x64 pixels with no sound.[8]
8. Image longevity
• Film and prints can fade, but digital images can
potentially last unchanged forever. However, the
media on which the digital images are stored can
decay or become corrupt, leading to a loss of image
integrity. Film and digital media should be stored
under archival conditions for maximum longevity.
Without backup it is easier to lose huge amounts of
digital data, for example by accidental deletion of
folders, or by failure of a mass storage device. In
comparison, each generation of copies of film
negatives and transparencies is degraded compared to
its parent. Film images can easily be converted to
digital (by using a digital film scanner for example)
with some possible loss of quality.
9. Colour reproduction
• Colour reproduction (gamut) is dependent on the type and quality of
film or sensor used and the quality of the optical system and film
processing. Different films and sensors have different color
sensitivity; the photographer needs to understand his equipment,
the light conditions, and the media used to ensure accurate colour
reproduction. Many digital cameras offer RAW format (sensor data),
which makes it possible to choose color space in the development
stage regardless of camera settings; in effect, the scene itself is
stored as far as the sensor allows, and can to some extent be
"rephotographed" with different color balance, exposure, etc.
Although RAW format can be used, the sensor and the camera's
dynamics can only capture in the GAMUT that the system will allow,
and when that image is transferred for reproduction on any device,
the best possible gamut that the person viewing the image will see
is the gamut of the end device. For a monitor, it would be the
screen's gamut. For a photographic print, it will be the gamut of the
device that printed the image on the paper.
10. Market impact
• In late 2002, 2 megapixel cameras were available
in the United States for less than $100, with some
1 megapixel cameras for under $60. At the same
time, many discount stores with photo labs
introduced a "digital front end", allowing
consumers to obtain true chemical prints (as
opposed to ink-jet prints) in an hour. These prices
were similar to those of prints made from film
negatives. However, because digital images have
a different aspect ratio than 35 mm film images,
people have started to realize that 4x6 inch prints
crop some of the image off the print. Some
photofinishers have started offering prints with the
same aspect ratio as the digital cameras record.
11. Social impact
• Throughout the history of photography, technological
advances in optics, camera production, developing, and
imaging have had an effect on the way people view images.
Up until 1960, most printed photographs were black and
white. Cameras that could print colour film began to be
popular in the 1960s, particularly with the introduction of the
Polaroid camera invented by Edwin Land, which could print
out a colour film print directly from the camera, within a few
minutes of taking the picture. Up until the advent of the
digital camera, amateur photographers could either buy print
film for their camera, or slide film. If they purchased slide
film, the resulting slides could be viewed using a slide
projector. Digital photography began to be available in the
early 2000s. The simultaneous increased use of
the Internet and email, relatively cheap computers and digital
cameras led to a tremendous increase in the number of
photographic images in digital formats
12. Recent research and innovation
• Research and development continues to refine the lighting,
optics, sensors, processing, storage, display, and software
used in digital photography. Here are a few examples.
• 3D models can be created from collections of normal images.
The resulting scene can be viewed from novel viewpoints, but
creating the model is very computationally intensive. An
example is Microsoft's Photosynth, which provides some
models of famous places as examples.[22]
• High dynamic range cameras and displays are commercially
available. Sensors with dynamic range in excess of
1,000,000:1 are in development, and software is also
available to combine multiple non-HDR images (shot with
different exposures) into an HDR image.
• Motion blur can be dramatically removed by a flutter
shutter (a flickering shutter that adds a signature to the blur,
which postprocessing recognizes).[23] It is not yet
commercially available.
13. Applications and considerations
• With the acceptable image quality and the other
advantages of digital photography (particularly the
time pressures of daily newspapers) the majority of
professional news photographers capture their images
with digital cameras.
• Digital photography has also been adopted by many
amateur snapshot photographers, who take
advantage of the convenience of sending images
by email, placing them on the World Wide Web, or
displaying them in digital picture frames. The majority
of cameras are camera phones integrated into cell
phones but their usual small, poor quality lenses and
sensors render most of them unsuitable for making
even moderate size prints.