VDIS10021 Working in Digital Design - Lecture 2 - DIGITAL vs TRADITIONAL PHOTOMEDIA

Lecturer: Rachel Hawkins

DIGITAL vs TRADITIONAL PHOTOMEDIA

VIRTU DESIGN INSTITUTEWORKING IN DIGITAL DESIGN VDIS10021

VIRTU DESIGN INSTITUTE: WORKING IN DIGITAL DESIGN - VDIS10021 4

HISTORY AND EVOLUTION OF PHOTOGRAPHYMARK OSTERMANGeorge Eastman House International Museum

of Photography and Film

GRANT B. ROMERGeorge 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). Th e “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 DaguerreIt 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 off er 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. Th e 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. Th ese images were beautiful, capable of infinite detail, but not permanent.

DaguerreotypeIn 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.

Th e resulting image, called a daguerreotype, was both positive and negative depending on the lighting and angle in which it was viewed. Th e 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 off ered the discovery to the world.

Every daguerreotype was unique. Th e final image was the very same plate that was in the camera during exposure. Th e 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 PaperWilliam 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 aff ected 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. Th is 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.

Th e 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


The Technical Evolution of Photography in the 19th Century

MARK OSTERMANGeorge Eastman House and International Museum of

Photography

Concept and First AttemptsWhereas 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 eff ect 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.

Th e 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. Th e 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. Th e term may have been fi rst 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 Th omas 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. Th ey 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. Th ey 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. Th e 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 NiépceSeveral 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. Th e 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. Th e 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.” Th e 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. Th is plate was exposed in a camera facing out the window of

The Technical Evolution of Photography in the 19th Century 27


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.

Th e photography collection at the George Eastman House International Museum includes more than 400,000 photographs

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 � 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 � 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 � 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 � 25.4cm. (Reproduced with permission of the Gernsheim Collection, Harry Ransom Humanities Research Center, University of Texas at Austin.)

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in May of 1839, “Th is is a miracle. Talbot’s [photogenic] draw-ings are childish compared with these.”

1839 — The Race for AcknowledgmentTalbot 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.” Th e report was read to the Royal Society on January 31 and subsequently published in the English journal Th e 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 off ered 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 HerschelHippolyte 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. Th e 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. Th e delicate printed-out image was washed in water and had reasonable permanence. Th e 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 eff ects of gelatin treated with chromium compounds. Th is 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. Th e 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 ProcessesThe improved daguerreotypeDaguerre’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 diff erent 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. Th e bromine fuming procedure eventually became standard prac-tice throughout the daguerreotype era, allowing daguerreo-typists to make exposures measured in seconds.

Th e 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. Th e 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. Th e process became known as gilding. Gilding extended the range of tones and made the fragile image highlight less susceptible to abrasion.

The calotypeTalbot’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


Go to the Lectures tab to find the ‘History and Evolution of Photography’ as written by Osterman and Romer.


Digital vs film photographyFrom 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 resolutionThe 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 grainThermal 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 SystemsIn 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.


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 rangeDynamic 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 sizeDrawing 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.


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 flexibilityFlexibility 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


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 speedDigital 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.

CleanlinessDust 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.

IntegrityFilm 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.

CostFilm 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.


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


Difference Between SLR and DSLRPictures 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


Photo Quality of Digital vs. Conventional CamerasThe 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.

DigitalThe 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


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

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.


GoPro CameraThe 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 PhonesWe 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.


PinterestPinterest 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.

InstagramInstagram 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.


FlickrFlickr (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 SelfieA 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.

VDIS10021 Working in Digital Design - Lecture 2 - DIGITAL vs TRADITIONAL PHOTOMEDIA

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Transcript of VDIS10021 Working in Digital Design - Lecture 2 - DIGITAL vs TRADITIONAL PHOTOMEDIA