4. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 4
HISTORY AND EVOLUTION
OF PHOTOGRAPHY
MARK OSTERMAN
George Eastman House International Museum
of Photography and Film
GRANT B. ROMER
George Eastman House International Museum
of Photography and Film
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28 HISTORY AND EVOLUTION OF PHOTOGRAPHY
his estate, known as Le Gras (Figures 38–40). The “View from
the Window at Le Gras,” now in the Gernsheim collection at the
Harry Ransom Center in Austin, Texas, probably took two days
of exposure to record the outline of the horizon and the most
primitive architectural elements of several buildings outside and
below the window. Niépce’s image is both negative and positive
depending on how it is illuminated, and it is permanent.
Louis Jacques Mandé Daguerre
It was 1826 when Louis Jacques Mandé Daguerre contacted
Niépce though the firm of Vincent and Charles Chevalier
(Figure 26), opticians in Paris from whom they were both
purchasing lenses for their experiments. Daguerre, inventor
of the popular Diorama in Paris, was also seeking a means to
secure images by light in a camera. At the time of their meeting,
Niépce was discouraged because of an unsuccessful trip to
London where he had tried to generate interest in his helio-
graph process. Daguerre had nothing more to offer than some
experiments with phosphorescent powder and a technique
called dessin fumee—drawings made with smoke (Figure 41).
Nevertheless, Niépce entered into partnership with Daguerre
in 1829 for the purpose of working toward a common goal.
It is assumed that he felt that Daguerre’s energy and popular
success would be of some benefit.
By the early 1830s, both Daguerre and Niépce observed
that light would darken polished silver that had been previ-
ously exposed to iodine fumes. Niépce used that same tech-
nique to darken the exposed portions of heliographs made on
polished silver plates. Niépce and Daguerre had also devel-
oped the physautotype, a variant of the heliograph that used
rosin instead of asphalt on silver plates. The process was
equally slow, but the images were superior to the heliograph,
looking more like the daguerreotype that was soon to be
invented. It is assumed that around this time Daguerre came
upon the process that would make him famous. His experi-
ments began by exposing silver plates fumed with iodine in
the back of a camera obscura. Given sufficient exposure, a fully
formed violet-colored negative image against a yellow ground
was made on the plate within the camera. These images were
beautiful, capable of infinite detail, but not permanent.
Daguerreotype
In 1833 Niépce died, leaving his heliograph process unpub-
lished and his son Isadore to assume partnership with
Daguerre. Two years after Niépce’s death, Daguerre discov-
ered that the silver iodide plate required only a fraction of the
exposure time and that an invisible, or latent, image that could
be revealed by exposing the plate to mercury fumes. Instead of
requiring an exposure of hours, the new process required only
minutes, and the image could be stabilized by treating it in a
bath of sodium chloride.
The resulting image, called a daguerreotype, was both
positive and negative depending on the lighting and angle in
which it was viewed. The image was established by a delicate,
frosty white color in the highlights and black in the polished
silver shadows, provided the plate was tilted toward a dark-
ened room. By the time he demonstrated the daguerreotype
process to Francois Arago, the director of the Paris Observa-
tory, Daguerre had a completely practical photographic system
that included fixing the image permanently with sodium thio-
sulfate, a process that was discovered by Sir John Herschel in
1819. Sodium thiosulfate was known at this time as hyposulfite
of soda or as hypo. In 1839 the French government awarded
Daguerre and Isidore Niépce a pension for the technology of
the daguerreotype and offered the discovery to the world.
Every daguerreotype was unique. The final image was the
very same plate that was in the camera during exposure. The
latent image and use of silver combined with iodine (silver
iodide) that were introduced by Daguerre became the basis
of every major camera process of the 19th century until the
introduction of gelatin bromide emulsions used in the manu-
facture of dry plates and developing-out papers.
Photography on Paper
William Henry Fox Talbot (Figure 36), an English scholar in the
area of hieroglyphics, began his own experiments with silver
chloride in 1834. Talbot, however, came to understand how
the percentages of silver nitrate to sodium chloride affected
sensitivity. Nevertheless, images made in the camera could
take hours. Why he did not use hypo to fix his images remains
a mystery since he was in communication with Herschel.
Hypo was an expensive chemical, and it is possible that Talbot
sought another compound for the sake of economy.
His observations, however, led him to discover a way of
making the unexposed areas of his images less sensitive. Talbot
treated his images in a strong solution of sodium chloride
and a dilute potassium iodide or potassium bromide, which
resulted in the colors brown, orange, yellow, red, green, and
lilac, depending on the chemical and degree of exposure. This
process did not actually remove the unexposed silver chloride,
so these images were simply considered “stabilized.” Provided
the image was not exposed to strong light, it could be preserved
for years or even used to make a positive image by contact
printing in the sun on a second piece of sensitized paper.
The process for both the stabilized negative and the subse-
quent positive print was called photogenic drawing. Like
all silver chloride papers, the exposures required for a fully
formed print were minutes for a contact image of a leaf printed
in the sun and up to several hours for a negative made within
a camera, depending on the size of the negative. Typically the
procedure of using the original negative to make a positive
print often darkened the former so much that it was useless for
printing a second time. By 1839 Talbot’s positive photogenic
drawings were colorful, soft in focus, and still relatively sensi-
tive. Compared to the speed, permanence, and infinitesimal
resolution attainable by the daguerreotype, the photogenic
drawing was very primitive, very slow, and impossible to
exhibit in daylight without a visible change. Sir John Herschel
is said to have remarked to Arago after seeing a daguerreotype
SECTION-Ia.indd 28 1/16/07 12:55:26 PM
The Technical Evolution of Photography
in the 19th Century
MARK OSTERMAN
George Eastman House and International Museum of
Photography
Concept and First Attempts
Whereas the observation of numerous light-sensitive
substances and the formative evolution of the camera obscura
predate 1800, the invention of photography, as we know it,
was essentially a 19th-century phenomenon. Who actually
invented photography has been disputed from the very begin-
ning, though the task would have been easier had there been a
universally accepted definition of photograph.
Taken literally, the Greek words photos and graphos
together mean “light drawing.” Even today the term photog-
raphy is being manipulated to fit digital imaging, but in its
most elegant form, a photograph may best be described as a
reasonably stable image made by the effect of light on a chem-
ical substance. Light is energy in the form of the visible spec-
trum. If light or some other invisible wavelength of energy
is not used to make the final picture by chemical means, it
cannot, by this definition, be a photograph.
The stability of an image made by light is also important.
Without stability, the term photograph could apply to the most
fragile and fugitive examples of images such as frost shadows
of buildings on a sunny November morning. The word photog-
raphy was not the product of just one man. Its introduction
was a logical choice by those with knowledge of Greek who
contemplated the concept. The term may have been first used
by Antoine Hercules Romuald Florence in 1833. Florence
was living in Brazil, working in relative isolation, and had no
apparent influence on the European scientific community. Sir
John Herschel (Figure 30), in England, also used the terms
photography and photograph in 1839, but his contacts were
many. Because of this Herschel has traditionally been credited
with the use of the terms by those seeking words to describe
both the process and product.
Some of the first images to be recorded with light-sensitive
materials were made by Thomas Wedgwood, son of Josiah
Wedgwood, the well-known potter. His associate, the scientist
Sir Humphrey Davy, published the results and observations in
the Journal of the Royal Institution in 1802. Wedgwood and
Davy made images on paper and white leather coated with
silver nitrate. They laid leaves and paintings on glass upon the
sensitive materials and exposed them to sunlight, which dark-
ened the silver. In an attempt to keep the image, they washed
the exposed materials without success. They found that
combining the silver solution with sodium chloride produced
the more sensitive whitish paste of silver chloride. Even with
this improvement, Wedgwood felt the process was too slow
to make images in a camera, and though they did make the
first photographic enlargements of microscopic specimens by
projecting the images using a solar microscope, they had no
way to preserve the image once it was formed.
Many of the observations of Wedgwood and Davy
were actually ideas already covered years earlier by Johann
Heinrich Schulze (1725), Carl Wilhelm Scheele (1777), and
Jean Senebier (1782), though without the same sense of
purpose. Schulze discovered the sensitivity of silver nitrate to
light rather than to heat. Scheele, in addition, observed and
published that ammonia would dissolve unexposed silver chlo-
ride, the means to permanently fix silver chloride images. It is
still difficult to understand why Scheele’s published observa-
tion escaped Davy. The experiments of Wedgwood and Davy
are important because their work combined photochemical
technology with the sole intent to make images with light. Few
doubt that success would have come to Wedgwood had he
applied ammonia to his images, but he died a few years after
publishing his findings. Davy did not continue the research.
Joseph Nicephore Niépce
Several years later Joseph Nicephore Niépce (Figure 110),
living in the village of Saint-Loup-de-Varennes near the town
Chalon-sur-Saône in France, began his own experiments using
paper sensitized with silver chloride. Some time around 1816,
Niépce made printed-out negative images on paper by using
a camera obscura and partially fixed them with nitric acid.
Not satisfied with the process, he moved on to another light-
sensitive material, asphaltum.
Niépce had been involved with etching and lithography
and was looking for a means to make etched plates without
having to depend on skilled handwork. It is probable that he
and others would have noticed that the asphalt etching ground
was harder to remove with solvents when printing plates were
exposed to the sun. He coated lithographic stones and plates of
copper, pewter, zinc, and glass with asphaltum dissolved in oil
of lavender. When the asphalt dried, the plates were covered
with an object and exposed to light. The unexposed areas were
then dissolved with a solvent such as Dippel’s oil, lavender
oil, or turpentine while the hardened exposed areas remained
intact, creating a negative image. Why Niépce did not use his
asphalt images on glass as negatives to make positive prints
on silver chloride paper remains a mystery to photographic
historians and scholars.
Niépce eventually placed waxed engravings in contact with
these sensitive plates. After the unexposed areas were removed
with a solvent, the plate negative image of the engraving
was visible. The plate was then etched with acid and subse-
quently used as a conventional etching plate for printing in a
press. Niépce called these plates heliographs, from the Greek
words helios and graphos, meaning “sun drawing.” The process
eventually became the conceptual cornerstone of the photo-
engraving industry.
Of all the heliographic plates made by Niépce, the only
known surviving example made in a camera has become an
icon of photographic history. In 1826 Niépce prepared a helio-
graph with a thinner asphalt coating upon polished pewter.
This plate was exposed in a camera facing out the window of
The Technical Evolution of Photography in the 19th Century 27
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136 HISTORY AND EVOLUTION OF PHOTOGRAPHY
noted, are courtesy of the Image Collection at the George
Eastman House International Museum of Photography and
Film in Rochester, New York.
The photography collection at the George Eastman House
InternationalMuseumincludesmorethan400,000photographs
FIG. 40 Digital print reproduction of “View from the Window at Le
Gras,” made by Harry Ransom Center and J. Paul Getty Museum,
June 2002. Color digital print reproduction, 20.3 ϫ 25.4cm.
(Reproduced with permission of the Gernsheim Collection, Harry
Ransom Humanities Research Center, University of Texas at Austin.)
FIG. 41 Louis Jacques Mandé Daguerre, French (1787–1851).
“Gothic Ruins,” ca. 1830. Dessin fumée, 7.7 ϫ 6cm. Gift of
Eastman Kodak Company, Gabriel Cromer collection.
FIG. 42 Samuel A. Bemis, American (ca. 1793–1881). “Abel
Crawford’s Inn at the Notch of the White Hills, White Mountains,
New Hampshire,” ca. 1840. Daguerreotype, 16.5 ϫ 21.6cm, full
plate. Gift of Eastman Kodak Company.
FIG. 39 Second version of “View from the Window at Le Gras,”
made by Helmut Gernsheim at the Kodak Research Laboratory
in Harrow, England. March 20–21, 1952. Gelatin silver print and
watercolor, 20.3 ϫ 25.4cm. (Reproduced with permission of the
Gernsheim Collection, Harry Ransom Humanities Research Center,
University of Texas at Austin.)
SECTION-Ic.indd 136 1/13/07 10:36:52 AM
in May of 1839, “This is a miracle. Talbot’s [photogenic] draw-
ings are childish compared with these.”
1839 — The Race for Acknowledgment
Talbot was caught off guard when Daguerre’s work was
announced by Arago to the Academy of Sciences in Paris
on January 7, 1839. Aware but not knowing the details of
Daguerre’s technique, Talbot rushed to publish his own photo-
genic drawing process in a report titled, “Some Account of
the Art of Photogenic Drawing.” The report was read to the
Royal Society on January 31 and subsequently published in
the English journal The Athenaeum on February 9. Talbot’s
account made a strong point of the utility of his process but
contained no specific formulas or details of the actual tech-
nique of making photogenic drawings.
Daguerre and Isidore Niépce had accepted a government
pension in exchange for the details of both the daguerreo-
type and heliograph processes. On August 19, 1839, Arago
explained the daguerreotype process in detail to a joint
meeting of the Academy of Science and the Academy of Fine
Arts at the Palace of the Institute in Paris. A daguerreotype
camera and complete set of processing equipment was manu-
factured by Giroux, Daguerre’s brother-in-law, and offered
for sale at this time. Daguerre also produced a manual, which
was the first of its kind and remains one of the most compre-
hensive photographic treatises ever written. Within its pages
are historical accounts, complete formulas, descriptions of
Niépce’s heliograph process with variations, and Daguerre’s
latent image process, and line illustrations of all the equipment
needed to make a daguerreotype.
Bayard, Ponton, and Herschel
Hippolyte Bayard, an official at the Ministry of Finance in
Paris, invented a direct positive process on paper in 1839.
His process was based on the light bleaching of exposed
silver chloride paper with a solution of potassium iodide. The
prints were then permanently fixed with hypo. Bayard sought
the attention of the French government to claim the inven-
tion of photography. His direct positive process was perma-
nent but very slow and was rejected in favor of Daguerre’s.
In 1840 Bayard submitted his process a second time and was
rejected again. In response he produced a self-portrait as a
drowned man and sent it to the Academy accompanied with
prose expressing his disappointment. Had this image been of a
leaf or piece of lace, like so many of Talbot’s photogenic draw-
ings, Bayard and his process would probably never have been
remembered with such pathos. In comparison, Bayard’s direct
positive self-portrait was technically superior to what Talbot
was making at the same time.
In 1839 Mungo Ponton, in Scotland, observed that paper
soaked in a saturated solution of potassium bichromate was
sensitive to light. The delicate printed-out image was washed
in water and had reasonable permanence. The process was
not strong enough for a positive print and not fast enough
for camera images, but Ponton’s work led Talbot to discover
the hardening effects of gelatin treated with chromium
compounds. This characteristic of dichromated colloids
became the basis of both carbon and gum printing and several
photomechanical printing processes.
In the same year, Sir John Herschel made hypo-fixed silver
carbonate negatives on paper. He also produced the first silver
halide image on glass by precipitating silver chloride onto the
surface of a plate and printing out a visible image within a
camera. The process was similar and as slow as the photogenic
drawing, however in this case the image was permanently
fixed with hypo. When this glass negative was backed with
dark cloth, it could be seen as a positive image. Herschel, who
could have invented photography, seems to have been satisfied
with helping others to do so. He held back on publicizing his
processes as a courtesy to Talbot.
Improvements to Daguerre’s and Talbot’s
Processes
The improved daguerreotype
Daguerre’s original process of 1839 was too slow to be used
comfortably for portraiture. Exposures were typically no less
than 20 minutes. Because of the slow lens and optics of the
time, the early daguerreotype process was limited to still-life
and landscape imagery. Two improvements that were to change
all this were the introduction of bromine fumes in the sensi-
tizing step of the process and the formulation of a faster lens.
In 1840 several experimenters working independently
discovered that different combinations of chlorine, bromine,
and iodine fumes could be used to produce daguerreotype
plates that were many times more sensitive than plates that
were simply iodized. Because of these experimenters’ research,
daguerreotypists eventually settled on fuming their plates
with iodine, then bromine, and once again with iodine. The
bromine fuming procedure eventually became standard prac-
tice throughout the daguerreotype era, allowing daguerreo-
typists to make exposures measured in seconds.
The design of a faster lens, formulated in 1840 by Max
Petzval, also allowed for shorter exposures. In combina-
tion with the more sensitive plate, this faster lens ushered in
the first practical application of the daguerreotype process
for portraiture. The Petzval lens was designed specifically for
portraiture and became the basis for all portrait and projec-
tion lenses for the next 70 years. By the early 1840s, commer-
cial daguerreotype portraits were being made in studios under
a skylight (Figure 45).
Another important improvement in 1840 was gold toning,
introduced by Hippolyte Fizeau. A solution of sel d’or, made by
adding gold chloride to hypo, was applied to the fixed plate.
The process became known as gilding. Gilding extended
the range of tones and made the fragile image highlight less
susceptible to abrasion.
The calotype
Talbot’s photogenic drawing process, as introduced, was also
impractical for portraiture even when improved lenses became
The Technical Evolution of Photography in the 19th Century 29
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Go to the Lectures tab
to find the ‘History
and Evolution of
Photography’ as
written by Osterman
and Romer.
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Digital vs film
photography
From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Digital_versus_film_photography
Digital versus film photography has been a topic
of debate in the photography world, as well as the
film industry since the availability of digital cameras
towards the end of the 20th Century. Both digital
still photography as well as digital cinematography
versus film and motion picture film photography have
advantages and drawbacks. 21st century photography
is now dominated by digital operation, but the older
photochemical methods continue to serve many users
and applications.
IMAGE QUALITY
Spatial resolution
The quality of digital photographs can be measured
in several ways. Pixel count is presumed to correlate
with spatial resolution. The quantity of picture
elements (pixels) in the image sensor is usually
counted in millions and called “megapixels” and
often used as a figure of merit. Digital cameras have
a variable relationship between final output image
resolution and sensor megapixel count. Other factors
are important in digital camera resolution, such as
the number of pixels used to resolve the image, the
effect of the Bayer pattern or other sensor filters on
the digital sensor and the image processing algorithm
used to interpolate sensor pixels to image pixels.
Digital sensors are generally arranged in a rectangular
grid pattern, making images susceptible to moire
pattern artifacts, whereas film is not affected by this
because of the random orientation of its grains.
The resolution of film images depends upon the area
of film used to record the image (35 mm, Medium
format or Large format) and the speed. Estimates of
a photograph’s resolution taken with a 35 mm film
camera vary. More information may be recorded if a
fine-grain film, combined with a specially formulated
developer, are used. Conversely, use of poor quality
optics or coarse-grained film yield lower image
resolution. A 36 mm x 24 mm frame of ISO 100-speed
film was initially estimated to contain the equivalent
of 20 million pixels, although this estimate was later
revised to between 4 and 16 million pixels depending
on the type of film used.
Many professional-quality film cameras use medium
format or large format films. Because of the size of
the imaging area, these can record higher resolution
images than current top-of-the-range digital cameras.
A medium format film image can record an equivalent
of approximately 50 megapixels, while large format
films can record around 200 megapixels (4 × 5 inch)
which equates to around 800 megapixels on the
largest common film format, 8 × 10 inches, without
accounting for lens sharpness. Medium format digital
provides from 39 to 80 megapixels.
Thus film and digital work each provide a wide range
of performance in this regard, overlapping but with
film tending to higher resolution. Resolution of both
film and digital are subject to the quality of lens fitted
to the camera. The medium which will be used for
display, and the viewing distance, should be taken
into account. For instance, if a photograph will only
be viewed on an old analogue television that can
resolve approximately 0.3 megapixel or modern
HDTV set of 1080p with 2 megapixels, the resolution
provided by high-end camera phones may suffice,
and inexpensive compact cameras usually will. Similar
or more expensive hardware may also fill the screens
of computer displays, though those few that show
tens of megapixels is currently out of reach of low-end
film photography and all but specialized scientific or
industrial digital cameras.
Noise and grain
Thermal noise, produced by heat and manufacturing
defects, degrades shadow areas of electronic images
with random pixels of the incorrect color. Film grain
becomes obvious in areas of even and delicate
tone. Grain and film sensitivity are linked, with more
sensitive films having more obvious grain. Likewise,
with digital cameras, images taken at higher sensitivity
settings show more image noise than those taken at
lower sensitivities.
However, even if both techniques have inherent
noise, it is widely appreciated that for color, digital
photography has much less noise/grain than film at
equivalent sensitivity, leading to an edge in image
quality. For black-and-white photography, grain
takes a more positive role in image quality, and such
comparisons are less valid.
Noise is a particularly critical issue with digital
cameras, often producing color distortion or confetti,
occurring most severely on the blue component
and least severely on the red component. Nearly
all digital cameras apply noise reduction to long
exposure photographs to counteract thermal noise.
For very long exposures, the image sensor must
be operated at low temperatures to prevent noise
affecting the final image. Film grain is not affected by
exposure time, although the apparent speed of the
film changes with lengthy exposures, a phenomenon
known as reciprocity failure.
Auto Focus And Auto Exposure Systems
In regards to compact cameras, digital compact
cameras have the advantage of using phase detection
or contrast detection on the actual image captured.
This is significantly more advantageous than compact
film cameras that use active infrared auto focus
systems which then estimate the lens position.
6. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 6
Similarly exposure levels can be detected directly
from the image sensor rather than through another
light meter used in film cameras. On the budget
end of the scale, digital compact cameras tend to
give better image quality than their budget film
counterparts due to these more superior focusing and
exposure mechanisms.
Dynamic range
Dynamic range is a complex issue. Comparisons
between film and digital media should consider:
Film type: For example, low-contrast print film has
greater dynamic range than slide film’s low dynamic
range and higher contrast.
Data format: Raw image format or JPEG?
Pixel density of the sensor: The large sensors in
DSLRs and medium format digital cameras generally
have larger photosites which collect more light and
therefore are generally more sensitive than their
diminutive counterparts in compact digital cameras.
The larger sensors tend to have better signal to
noise characteristics. However signal processing and
amplification improves with generation and small
sensors of today approach the dynamic range of large
sensors in the past.
Scanner: Variations in optics, sensor resolution, scanner
dynamic range and precision of the analogue to digital
conversion circuit cause variations in image quality.
Optical versus digital prints: Prints differ between
media and between images shown on Visual display
units.
Signal/noise ratio: This defines the limits of dynamic
range within a single photograph, and may vary
with subject matter. A single comparison cannot
demonstrate that digital or film has a smaller or
greater dynamic range.
Dynamic range is of considerable importance to
image quality in both the digital and emulsion
domain. Both film and digital sensors exhibit non-
linear responses to the amount of light, and at the
edges of the dynamic range, close to underexposure
and overexposure the media will exhibit particularly
non-linear responses. The non-linear dynamic
response or saturation qualities of emulsion film are
often considered a desirable effect by photographers,
and the distortion of colour, contrast and brightness
varies considerably between film stocks. There is
no limit to the number of possible levels of colour
on emulsion film, whereas a digital sensor stores
integer numbers, producing a limited and specific
possible number of colours. Banding may be visible
in the unusual case that it is not obscured by noise,
and detail may be lost, particularly in shadow and
highlight areas.
According to Eastman Kodak in 2007, digital sensors
of the time lacked the extended dynamic range of
film. In particular, they tend to ‘blow out’ highlights,
losing detail in very bright parts of the image. If
highlight detail is lost, it is nearly impossible to
recapture in post-production. Therefore, film can be
underexposed and overexposed, retaining detail and
information in the camera negative.
Some amateur authors have performed tests
with inconclusive results. R. N. Clark, comparing a
professional digital camera with scans of 35 mm film
made using a consumer level scanner, concluded that
“Digital cameras, like the Canon 1D Mark II, show a
huge dynamic range compared to [scans of] either
print or slide film, at least for the films compared.”
Carson Wilson informally compared Kodak Gold 200
film with a Nikon D60 digital camera and concluded
that “In this test a high-end consumer digicam fell
short of normal consumer color print film in the
area of dynamic range.” The digital camera industry
is attempting to address the problem of dynamic
range. Some cameras have an automatic exposure
bracketing mode, to be used in conjunction with
high dynamic range imaging software. Some CCDs
including Fujifilm’s Super CCD combine photosites of
different sizes to give increased dynamic range. Other
manufacturers use in-camera software to prevent
highlight overexposure. Nikon calls this feature
D-Lighting.
Presentation technology is also relevant, as different
color printing methods, cathode-ray tubes, LCDs and
other displays all have different dynamic range limits
and degrees of linearity.
Effects of sensor size
Drawing showing the relative sizes of sensors used in
most current digital cameras.
Almost all compact digital cameras, and most digital
SLRs or ILCs, have sensors smaller than the 36 mm x
24 mm exposure-frame of “35 mm” film. The smaller
sensors found in DSLR cameras affect:
• Depth of field;
• Light sensitivity and pixel noise;
• Relative cropping of the field of view when using
lenses designed for 35 mm camera;
• Optimizing lens design for smaller sensor area;
• Increased relative enlargement of the captured
image.
Depth of field is often quoted as being greater for
digital cameras than for film cameras. The maxim
packages several counterintuitive aspects of
photography into a single (largely correct) theorem.
Depth of field, for a given lens focal length, at a
given f-number will scale with sensor (film/chip) size.
In effect, a smaller sensor will increase the apparent
depth of field because it magnifies the portion of the
image that is in focus.
7. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 7
Manufacturers are increasingly using (especially in
the budget digital camera market) “35 millimeter
equivalent” focal lengths for lenses. This gives rise
to the “depth of field is greater for digital cameras”
myth: the shorter the focal length of a lens, the
greater is its depth of field (at fixed F-stop). Therefore,
if a sensor that is one-fourth the width and height of
a 24 x 36 mm frame of film is exposed to an image
through a lens that is correspondingly one-fourth the
focal length, the depth of field increases 16x (scaling
per the square of focal length) on an absolute scale,
but 4x from a comparison-of-images perspective (the
imaging dimension is 4x smaller).
This increase in relative depth-of-field may have
advantages for taking snapshots; more image will
be in focus than with a larger sensor and autofocus
system accuracy is less critical for producing an
acceptable image. Contrarily, photographers wishing
to decrease depth of field to create certain effects,
such as isolating subjects from their background need
to increase aperture for sensors smaller than 36 mm
x 24 mm to achieve the same degree of selective
focusing. Depth of field can be minimized by use of
large format cameras, which are very rarely digital.
Light sensitivity and pixel noise are both related
to pixel size, which is in turn related to sensor size
and resolution. As the resolution of sensors of a
specific format increases, the size of the individual
pixels naturally has to decrease. This smaller pixel
size means that each pixel collects less light and the
resulting signal must be amplified more to produce
the final value. Noise is also amplified and the signal-
to-noise ratio decreases, and the higher noise floor
means that less useful information is extracted from
the darker parts of the image. Countering these
effects of digital-signal noise are advances being
made in sensor technology itself. As of 2012, the
top-end of digital sensor sensitivity is at ISO 204,800
(in both Canon and Nikon DSLRs), whereas less
expensive prosumer DSLR and ILC cameras offer
sensitivities up to ISO 6400 or even higher, often with
good noise performance at one-quarter maximum
sensitivity. In recent years larger sensor digital
compacts have become available. However, they
still are bigger and heavier than the smallest 35mm
cameras and are not full frame.
Some digital SLRs use lens mounts originally
designed for film cameras. If the camera has a smaller
imaging area than the lens’ intended film frame, its
field of view is cropped. This crop factor is often called
a “focal length multiplier” because the effect can be
calculated by multiplying the focal length of the lens.
For lenses that are not designed for a smaller imaging
area whilst using the 35 mm-compatible lens mount,
this has the beneficial side effect of only using the
centre part of the lens, where the image quality is in
some aspects higher. Only expensive digital SLRs and
very rarely expensive ‘compacts’ have 36mm × 24 mm
sensors, eliminating depth of field and crop factor
problems when compared to 35 mm film cameras.
In compact digital cameras, the size of the sensor is
often several times smaller than the standard 36 mm
x 24 mm film, with the area being typically 20 to 40
times less than that of a frame of film. This difference
gives film compacts a substantial advantage when
it comes to image quality and the ability to take
pleasing portraits. In the standard consumer market
film’s advantage over digital in the compact market is
often negated by operator error, the generally poor
quality of the cameras or because of poor quality
processing of films. The smaller sensor size of digital
compact cameras means that prints are extreme
enlargements of the focused image, and that the
lens must perform well in order to provide enough
resolution to match the tiny pixels on the sensor.
To manufacturers, large lenses are very costly to
produce, smaller sensors in digital cameras enable
the use of smaller and more compact arrangement
of lenses. Affordable super-zooms cameras that
can magnify images 50-60 times are now available.
These kinds of magnification are virtually impossible
to achieve in 35mm film cameras. Compact cameras
such as the Lumix LX-7 with a maximum aperture of
f/1.4 is achievable with smaller sensors.
Convenience and flexibility
Flexibility and convenience are among the reasons
for the widespread adoption of digital cameras. With
film cameras, a roll is usually completely exposed
before being processed. When the film is returned it
is possible to see the photograph, but most digital
cameras incorporate a liquid crystal display that
allows the image to be viewed immediately after
capture. The photographer may delete undesired
or unnecessary photographs, or re-shoot the image
if required. A user who wants prints can quickly and
easily print just the required photographs.
Photographic film is made with specific characteristics
of Color temperature and sensitivity (ISO). Lighting
conditions often require characteristics different
from those of the film specifications, requiring the
use of filters or corrections in processing. Digital
photography allows color temperature and sensitivity
to be adjusted at each shot, either manually or
automatically.
Digital images may be conveniently stored on a
personal computer or in off-line storage such as small
memory cards. Professional-grade digital cameras
can store pictures in a raw image format, which stores
the output from the sensor rather than processing
it immediately to form an image. When edited in
suitable software, such as Adobe Photoshop or the
GNU program GIMP (which uses dcraw to read raw
files), the user may manipulate certain parameters,
such as contrast, sharpness or color balance before
producing an image. JPEG images can be similarly
8. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 8
manipulated, though usually less precisely; software
for this purpose may be provided with consumer-
grade cameras. Digital photography allows the quick
collection of a large quantity of archival documents,
bringing convenience, lower cost and increased
flexibility in using the documents.
Modern film cameras are not as power thirsty as
modern digital cameras, and can last longer on smaller
batteries. Some film cameras, especially older ones,
can operate without batteries: some will function
completely without batteries while others may lose
some functionality such as metering and some shutter
speeds. Batteries that only have to power light meters
are often very small and can last a long time. This can
be a boon for those who may be spending a long time
with little or no access to power. Film cameras may also
be carried as backups for this reason.
For large format and ultra large format photography,
film may have some advantages over digital
cameras, such as price and flexibility, when used
outside the studio environment. Digital rotating line
cameras provide similarly high performance, but
scan mechanically rather than use a single sensor.
Thus they cannot scan anything that moves, and are
expensive, large, and rarely moved.
Film speed
Digital cameras are capable of much higher speeds
(sensitivities) than film, can perform more desirably
in low light situations at night or indoors, and are
more useful for ultra-fast photography. In addition,
on digital cameras the speed can be adjusted at any
time, while a film camera requires changing the film to
change the film speed.
Cleanliness
Dust on the image plane is a constant issue
for photographers, and especially so in digital
photography. DSLR cameras are especially prone to
dust problems because the sensor remains in place,
whereas a film advances through the camera for
each exposure. Debris in the camera, such as dust or
sand, may scratch the film; a single grain of sand can
damage a whole roll of film. As film cameras age, they
can develop burs in their rollers. With a digital SLR,
dust is difficult to avoid but is easy to rectify using a
computer with image-editing software. Some digital
SLRs have systems that remove dust from the sensor
by vibrating or knocking it, sometimes in conjunction
with software that remembers where dust is located
and removes dust-affected pixels from images.
Compact digital cameras are fitted with fixed lenses,
which makes it harder for dust to get into the image
area. Similar film cameras are often only light-tight
and not environmentally sealed. Some modern
DSLRs, like the Olympus E-3, incorporate extensive
dust and weather seals to avoid this problem.
Integrity
Film produces a first generation image, which
contains only the information admitted through the
aperture of the camera. Trick photography is more
difficult with film; in law enforcement and where the
authenticity of an image is important, like passport
or visa photographs, film provides greater security
over most digital cameras, as digital files may have
been modified using a computer. However, some
digital cameras can produce authenticated images.
If someone modifies an authenticated image, it can
be determined with special software. SanDisk claims
to have developed a write-once memory stick for
cameras, and that the images once written cannot
be altered. Nikon film scanner, right, which images
35 mm film for digital input. From an artistically
conservative standpoint, some practitioners believe
that the use of film offers a more authentic mode of
expression than with easily enhanced digital images.
As with the earlier transition from oil painting to
photography, or from photographic plates to film
photography, older methods are more expensive,
thus encourage more selectivity and additional
consideration.
Cost
Film and digital imaging systems have different
cost emphases. Digital cameras are significantly
more expensive to purchase than film equivalents.
Prices are however dropping rapidly due to intense
competition. Film cameras, on the other hand,
are quite inexpensive to purchase, especially used
equipment. But film and development costs are
ongoing. However, in the digital realm, it could be
argued that the constant state of technological
change will cause a digital user to keep upgrading
and buying other equipment once their digital
camera becomes quickly obsolete.[24] Other costs
of digital photography include specialist batteries,
memory cards and long-term data storage. The
emergence of very high quality phone cameras since
the early 2010s are making lower end, small sensor
digital cameras redundant, almost as quickly as they
grew in the last decade. Manufacturers are focusing
attention to premium models such as compact system
cameras and large sensor compacts. Mobile phones
such as the iPhone 5S, Samsung Galaxy S4 and the
Nokia Lumia 1020 are capable of images that can rival
or beat cheaper dedicated cameras. Inkjet printers
can make low-quality prints cheaply and easily from
digital files, but high-quality printing has high costs
regardless of image source.
9. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 9
How an SLR Camera Works:
An SLR camera is a SINGLE LENS REFLEX Camera. Light enters
through a single lens at the front of the camera, and is reflected on a
mirror or sensor in the camera, recording the light. An aperture ring
inside the SLR camera adjusts how much light may enter the camera.
The shutter speed function on an SLR camera adjusts how long the light
may enter the camera. Photography is simply a recording of light on film
emulsion, or a digital sensor.
An SLR camera can be made as a film-based or digital-based camera.
Both styles accept a variety of accessories, including lenses, flash units,
remote controls, filters and tripods or monopods. These different
accessories allow the photographer to change the look of the photo.
A compact film or digital camera doesn’t have as much versatility as an
SLR camera.
Lenses that work with an SLR Camera:
An SLR camera can accept a variety of lenses. A telephoto, or
zoom lens, can be mounted on the SLR camera body to allow the
photographer the ability to zoom in close on a subject that is far away.
The resulting picture will make it seem as though the photographer was
close to the subject.
A wide-angle lens can also be mounted on an SLR camera. This type of
lens allows the photographer to get a wide view, even in tight spaces,
such as a small room.
Specialty lenses, such as macro lenses, allow the photographer to
photograph very small objects with close-up detail. Close-up filters allow
a similar effect, but must be used in bright situations, since they cut
down on the amount of light that can get into the SLR camera body.
Accessories that work with an SLR Camera:
SLR cameras illuminate subjects at a distance better than a compact
camera, since they can use an external flash unit to brighten a
photograph. Mounted on the top of an SLR camera, a flash unit can
project light up to ten times further than a small built in flash on a
compact camera. This is very helpful when photographing sports and
stage productions.
A tripod or monopod can be threaded into the base of an SLR camera
for stability. A tripod will allow the camera to stand alone on three legs,
and be operated with a remote control or delayed shutter function. A
monopod gives stability to an SLR camera with a heavy lens, and makes
it easier to shoot for a long period of time with a heavy set-up.
http://www.ehow.com/how-does_4586313_slr-camera-work.html
10. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 10
Difference Between
SLR and DSLR
Pictures are an integral part in keeping memories. Before the days
of digital photography, there was film. Although film has started to
disappear from the general public view in the last few years, it’s where
we begin our discussion.
SLR or Single Lens Reflex camera are a class of cameras that allowed
for much better photographs due to an innovative solution to an old
problem. Most cameras have two light paths from the target, one
leading to the lens itself while the other to the viewfinder. This leads
to the final photo being slightly different from what you saw on the
viewfinder. SLR cameras fixed this by using a certain mechanism that lets
you see through the lens. After you push the button to take the picture,
the mechanism then moves to let the light hit the film behind it.
Most SLR’s are used in professional photography, where the need for
utmost quality is very high. It would not be surprising that most of
the advanced features also appear on SLRs and not on the common
camera.
At the early stages of photography, the LCD viewfinder grew in
popularity. Since the LCD viewfinder usually takes its image on the
image sensor, it should already be considered as an SLR; but it isn’t.
SLRs have begun to become a class of high end cameras with more
advanced features, like manual controls, interchangeable lenses, among
others. It was no longer just about the path of light.
DSLR or the Digital version of SLR is basically an SLR that has been
converted from saving the image in film to saving an image in a memory
card. It still shares a lot of the advanced features of the SLR along with a
few more improvements that makes it a lot more superior.
The nature of memory cards and the high capacities that are available
today means that a professional photographer would not need to
change the storage medium as often. The use of very high quality
sensors coupled with the capability to instantly review the image you
took also gives modern day photographers an undeniable edge.
Despite being a few folds more expensive compared to their
counterparts, the SLR and the DSLR were an indispensable tool in
professional photography. Even hobbyists who have the money can
enjoy and enhance their talents on photography. As most technologies
evolve, so does the technology in photography. The DSLR is just the
next evolutionary step from the SLR.
http://www.differencebetween.net/object/difference-between-slr-and-dslr/#ixzz35FcQJJxO
11. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 11
Photo Quality of Digital
vs. Conventional Cameras
The past years have seen major technological breakthroughs especially
in the digital field. Electronic devices are built on the basic premise of
converting conventional analog information into digital information.
The digital camera is one of these devices that exemplify the big
difference between the world of analog and the digital. It is totally
different from its predecessor, the conventional cameras. Obviously,
conventional cameras depend entirely on mechanical and chemical
processes. You don’t need electricity to operate on one. In addition,
with conventional cameras, film is needed to take photos, which leads
to a lot of problems such as film flatness, inconsistent development, or
scanners. All digital cameras have a built-in computer, and all of them
record images in an entirely electronic form. As such, images can be
previewed immediately - no more trips to camera shops to drop off film
then picking it up again. Not to mention, no more worries on airport
x-rays.
Aside from the basic disparity of the process of operation, photo quality
also makes a world of distinction between the two.
Conventional Cameras
Film is an analog medium, so it doesn’t have “pixels”. The finest films
(which are slow and need a lot of light) have very fine grains. Finer grains
mean more grains per inch. This means more detail in your image which
will allow you to enlarge your photos to a much bigger size without the
visibility of deterioration. If your objective is to take advantage of these
pixels, you need to work on your lighting conditions and the quality of
the optics used. The latest generation of Pro Digital Cameras is reaching
these resolutions but at prices that are 5 to 10 times higher than that of
a conventional camera that could equal the kind of resolution you want.
If you want to get the maximum advantage from your film, you need to
use the best optics you can get from your camera system. Cheap optics
can have a low resolving power due to imperfections in the glass quality
and the coatings used. In addition, sharpness, brightness and contrast
depend strongly on the quality of your lenses.
Next to pixel count, each grain can be set to display any colour, colour
intensity and brightness. On a digital camera, this is limited by the
“color depth” as each pixel can be set to a limited number of levels.
One important factor to be considered with conventional cameras is
that the images are only previewed by you after they are processed at
the lab, not during the time you took the shot as in the case of a digital
camera. You are completely in the dark whether it’s good or bad images.
Furthermore, you have to pay for all your prints. There is also little
you can do to post process your shot unless you have access to a well
equipped darkroom.
Digital
The highest resolution available is 14 mega pixels with a very expensive
professional camera. But 6 Mega-pixel pro-summer digital cameras can
be bought at a much cheaper price. These digital cameras are already
capable of producing a 3000 x 2000 pixels image. This means that it is
capable of producing an A4 size image.
Digital cameras have larger image sensors than the average pocket
digicams. They produce better images than that of a pocket camera
with the same resolution. This is possible because the larger image
sensor of the digital camera is less sensitive to stray electrical signals.
A smaller sized sensor produces more ‘noise’. Noise in digital cameras
is much lower than grain in film. This can be seen as small variations
in color and tone in image. As the ‘amplifiers’ in the sensor make the
electrical signals stronger with each higher ISO setting, the amount of
12. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 12
noise will also increase. This is comparable to bigger grains on high speed
conventional film.
The advantages of digital cameras are many and very popular. Direct
preview of results make it possible for you to re-shoot and adjust
the composition or exposure as needed. And unlike its conventional
counterpart, once you bought your equipment, there is no additional cost
in the pictures you take even when it’s more than a hundred times. Just
simply store your shots, and when you want some prints, you can simply
send them to your local photo lab and print only what you need and want.
These help you to become more unconventional and try out different
experiments that you would normally avoid with conventional film. More
shots increases the chances of good images, thereby making you a better
photographer.
But don’t get me wrong. I love the conformity and traditionalism of having
a conventional camera. In fact, it may even be decades before digital
cameras completely replace film cameras. Your choice between the two
cameras depends entirely on what you want to do with your images. When
you need A3 size (or even larger) print with superb professional quality, you
still need to go for the more conventional camera, especially those that
are top of the line. They’re just a bit expensive though. Digital is going
through a fast stage of development and sometimes doesn’t have the
same resolution capability as that of its counterpart.
Also, if you’re not too keen with the use of computers, you should
probably stay with conventional cameras.
Nevertheless, if you are primarily concerned with taking relatively small
images for email or to use on a web page, then an inexpensive digital
camera will do. Combined with appropriate post-processing, you are now
able to create artistic and creative results with the range of digital cameras
in the market today.
http://digitaltrends.blogspot.com.au/2004/12/photo-quality-of-digital-vs.html
13. NEW TRENDS IN
DIGITAL PHOTOMEDIA
Due to advancements in technology and social media
there are several new trends and developments in the
way we take photos, access them and share them.
These are relevant to how photography is viewed and
used in commercial design media.
14. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 14
GoPro Camera
The GoPro is an HD-quality, waterproof, video recording device. It
has gained such popularity because it is very small and compact,
yet it can deliver amazingly crystal-clear video. They are most often
used in extreme action video photography. They are known for being
lightweight, rugged, wearable or mountable in unusual places such as
outside a quadcopter, planes, cars, boats or army tanks. They can be
attached to your helmut, worn on a chest harness or can be carried via a
‘mount’, an arm like stick to hold out from the body.
The GoPro enables people to capture their experiences as they
experience it. It allows for a self documentary. This form of photography
is totally new and cutting edge while also accessible to the masses.
Smart Phones
We all walk around with a smart phone in our pockets loaded up with
social media apps and an accessible camera ready to capture our
everyday moments. Cameras have been mass produced and accessible
for some time however smart phones have seen the development
of incredibly compact cameras that fit in our pockets. Not only can
we have our camera with us all the time and take photos easily and
conveniently, but we can share these photos instantly with wireless
connections. We can even print the photos with a wireless connection.
The smart phone has seen an increase in people taking photos and
sharing the data online. It has also fed the obsession for the selfie and
driven the creation of applications such as Instagram and Pinterest.
15. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 15
Pinterest
Pinterest is a visual discovery tool that people use to collect ideas for
their different projects and interests. The site was founded by Ben
Silbermann, Paul Sciarra and Evan Sharp. It is managed by Cold Brew
Labs and funded by a small group of entrepreneurs and investors.
Pinterest is a free website in which users can upload, save, sort and
manage images, known as pins, and other media content (e.g. videos
and gifs) through collections known as pinboards. Pinterest acts as a
personalized media platform, whereby users’ content and the content
of others can be browsed on the main page. Users can then save
individual pins to one of their own boards using the “Pin It” button, with
Pinboards typically organized by a central topic or theme. Users can
personalize their experience with Pinterest by pinning items, creating
boards, and interacting with other members. By doing so, the users “pin
feed” will display unique, personalized results.
Instagram
Instagram is an online mobile photo-sharing, video-sharing and social
networking service that enables its users to take pictures and videos,
apply digital filters to them, and share them on a variety of social
networking services, such as Facebook, Twitter, Tumblr and Flickr. A
distinctive feature is that it confines photos to a square shape, similar
to Kodak Instamatic and Polaroid images, in contrast to the 4:3 aspect
ratio typically used by mobile device cameras. Users are also able to
record and share short videos lasting for up to 15 seconds.
Instagram was created by Kevin Systrom and Mike Krieger and launched
in October 2010. The service rapidly gained popularity, with over 100
million active users as of April 2012. The app allows users to apply a
series of borders an effects to their photos that may enhance the image.
16. VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 16
Flickr
Flickr (pronounced “flicker”) is an image hosting and video hosting
website, and web services suite that was created by Ludicorp in 2004
and acquired by Yahoo in 2005. In addition to being a popular website
for users to share and embed personal photographs, and effectively an
online community, the service is widely used by photo researchers and
by bloggers to host images that they embed in blogs and social media.
All your pictures in one place. On Flickr, everyone gets 1000GB of free
storage, enough space for more than 500,000 photos. The powerful
search technology means you can find them anytime you want. No
matter where you are, automatically sync your phone’s photos to Flickr.
The Selfie
A selfie is a self-portrait photograph, typically taken with a hand-held
digital camera or camera phone. Selfies are often shared on social
networking services such as Instagram, Snapchat, and Tumblr. They
are often casual, and are typically taken either with a camera held at
arm’s length or in a mirror. Initially popular with young people, selfies
gained wider popularity over time. By the end of 2012, Time magazine
considered selfie one of the “top 10 buzzwords” of that year; although
selfies had existed long before, it was in 2012 that the term “really
hit the big time”. According to a 2013 survey, two-thirds of Australian
women age 18–35 take selfies - the most common purpose for which is
posting on Facebook. A poll commissioned by smartphone and camera
maker Samsung found that selfies make up 30% of the photos taken by
people aged 18–24.
By 2013, the word “selfie” had become commonplace enough to be
monitored for inclusion in the online version of the Oxford English
Dictionary. In November 2013, the word “selfie” was announced as
being the “word of the year” by the Oxford English Dictionary, which
gave the word itself an Australian origin.