A good way to remember how the depth of field is affected by aperture. Is that Ansel Adams belonged to the f64 club. Now as a great landscape photographer unless he wanted a aperture that had a large depth of field. So he chose the large number (small hole) that had a large depth of fields for his era.
Here is video on the subject.
Foreground and background can be out of focus in shallow depth of field.
http://isleofmanmansions.blogspot.com/
So a F2 is a narrow depth of field.
F22 is a deep depth of field.
Saturday, 27 February 2010
Improve Your Street Photography Skills, Digital Photographer issue 77
Improve Your Street Photography Skills, Digital Photographer issue 77
http://isleofmanmansions.blogspot.com/
http://isleofmanmansions.blogspot.com/
data storage device
A data storage device is a device for recording (storing) information (data). Recording can be done using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs.
Devices that are not used exclusively for recording (e.g. hands, mouths, musical instruments) and devices that are intermediate in the storing/retrieving process (e.g. eyes, ears, cameras, scanners, microphones, speakers, monitors, projectors) are not usually considered storage devices. Devices that are exclusively for recording (e.g. printers), exclusively for reading (e.g. barcode readers), or devices that process only one form of information (e.g. phonographs) may or may not be considered storage devices. In computing these are known as input/output devices.
An organic brain may or may not be considered a data storage device.
All information is data. However, not all data is information.
Many data storage devices are also media players. Any device that can store and playback multimedia may also be considered a media player such as in the case with the HDD media player. Designated hard drives are used to play saved or streaming media on home entertainment systems.
http://isleofmanmansions.blogspot.com/
Devices that are not used exclusively for recording (e.g. hands, mouths, musical instruments) and devices that are intermediate in the storing/retrieving process (e.g. eyes, ears, cameras, scanners, microphones, speakers, monitors, projectors) are not usually considered storage devices. Devices that are exclusively for recording (e.g. printers), exclusively for reading (e.g. barcode readers), or devices that process only one form of information (e.g. phonographs) may or may not be considered storage devices. In computing these are known as input/output devices.
An organic brain may or may not be considered a data storage device.
All information is data. However, not all data is information.
Many data storage devices are also media players. Any device that can store and playback multimedia may also be considered a media player such as in the case with the HDD media player. Designated hard drives are used to play saved or streaming media on home entertainment systems.
http://isleofmanmansions.blogspot.com/
The Term Format in photography
What is format?
A format is simply the size of recording medium.
Landscape Photography- Medium/Large Format
Large format describes large photographic films, large cameras, view cameras (including pinhole cameras) and processes that use a film or digital sensor, generally 4 x 5 inches or larger. The most common large formats are 4x5 and 8x10 inches. Less common formats include quarter-plate, 5x7 inches, 11x14 inches, 16x20 inches, 20x24 inches, various panoramic or "banquet" formats (such as 4x10 and 8x20 inches), as well as metric formats, including 9x12 cm, 10x13 cm, and 13x18 cm.
The Polaroid 20x24 inch instant camera is one of the largest format cameras currently in common usage, and can be hired from Polaroid agents in various countries. Many well-known photographers have used the 235 pound (106 kg), wheeled-chassis Polaroid.
The 4x5 inch sheet film format was very convenient for press photography since it allowed for direct contact printing on the printing plate. This was done well into 1940s and 1950s, even with the advent of more convenient and compact medium format or 35 mm roll-film cameras which started to appear in the 1930s. The 35mm and medium format SLR which appeared in the mid-1950s were soon adopted by press photographers.
Large-format photography is not limited to film; large digital camera backs are available to fit large-format cameras. These are either medium-format digital backs adapted to fit large-format cameras (sometimes resulting in cropped images), step and repeat Multishot systems, or scanning backs (which scan the image area in the manner of a flat-bed scanner). Scanning backs can take seconds or even minutes to capture an image. When using a Sinar Macroscan unit and 54H data files, over 1 GB of data can be captured.
Large format, both film-based and digital, is still used for many applications, for example: landscape photography, advertising photos, fine-art photography, scientific applications and generally for images that will be enlarged to a high magnification while requiring a high level of detail.
In the printing industry, very large fixed cameras were also used to make large films for the preparation of lithographic plates before computer to film and computer to plate techniques were introduced.
Image file formats are standardized means of organizing and storing images. This entry is about digital image formats used to store photographic and other images; (for disk-image file formats see Disk image). Image files are composed of either pixel or vector (geometric) data that are rasterized to pixels when displayed (with few exceptions) in a vector graphic display. The pixels that constitute an image are ordered as a grid (columns and rows); each pixel consists of numbers representing magnitudes of brightness and color.
A pinhole camera is a very simple camera with no lens and a single very small aperture. Simply explained, it is a light proof box with a small hole in one side. Light from a scene passes through this single point and projects an inverted image on the opposite side of the box. Cameras using small apertures and the human eye in bright light both act like a pinhole camera.
In photography, a sheet of ground glass is used for the manual focusing in some still and motion picture cameras. Some cameras have no separate viewfinder, but instead use a piece of ground glass at the focal plane to focus the scene. This type of focusing and viewing system is typically used on so-called large format cameras (cameras which use film 4×5 inches or larger). In such a camera, before the picture is taken, the ground-glass viewer is inserted in the back of the camera, and the lens opened to its widest aperture. This projects the scene on the ground glass upside down and backwards. The photographer focuses and composes using this projected image, sometimes with the aid of a magnifying glass (or loupe). In order to see the image better, a dark cloth is used to block out light, whence came the image of the old-time photographer with his head stuck under a large black cloth.
Large format, both film based and digital, is still used for many applications, for example: landscape photography, advertising photos, fine-art photography, scientific applications and generally for images that will be enlarged to a high magnification while requiring a high level of detail.
A medium format and large format camera can be heavy.
Medium format has traditionally referred to a film format in still photography and the related cameras and equipment that use this film. Generally, the term applies to film and cameras used to produce images larger than the 24 by 36 mm of 135 film, but smaller than the 4”×5” size, which is considered to be large format.
Generally, the term applies to film and cameras used to produce images larger than the 24 by 36 mm of 135 film, but smaller than the 4”×5” size, which is considered to be large format.
So medium format applies to film that is larger than 24 X 36 but smaller than 4 x 5.
In digital, medium format is currently a very expensive option, with typical brand new all digital medium format cameras retailing for $10,000 (Mamiya ZD) to $32,000 (Hasselblad H3D) in 2008, though, older and used equipment can be substantially cheaper.
Toy cameras are simple, inexpensive film box cameras made almost entirely out of plastic, often including the lens. The term is misleading, since they are not merely 'toys' but are in fact capable of taking photographs. Many were made to be given away as novelties or prizes. The Diana, an inexpensive 1960s 4x4cm novelty box camera from Hong Kong, is typically the camera most associated with the term 'toy camera'. Other cameras, such as the LOMO LC-A, Lubitel, and Holga, while originally intended as consumer, mass-market cameras, have also become identified with the term.
A format is simply the size of recording medium.
Landscape Photography- Medium/Large Format
Large format describes large photographic films, large cameras, view cameras (including pinhole cameras) and processes that use a film or digital sensor, generally 4 x 5 inches or larger. The most common large formats are 4x5 and 8x10 inches. Less common formats include quarter-plate, 5x7 inches, 11x14 inches, 16x20 inches, 20x24 inches, various panoramic or "banquet" formats (such as 4x10 and 8x20 inches), as well as metric formats, including 9x12 cm, 10x13 cm, and 13x18 cm.
The Polaroid 20x24 inch instant camera is one of the largest format cameras currently in common usage, and can be hired from Polaroid agents in various countries. Many well-known photographers have used the 235 pound (106 kg), wheeled-chassis Polaroid.
The 4x5 inch sheet film format was very convenient for press photography since it allowed for direct contact printing on the printing plate. This was done well into 1940s and 1950s, even with the advent of more convenient and compact medium format or 35 mm roll-film cameras which started to appear in the 1930s. The 35mm and medium format SLR which appeared in the mid-1950s were soon adopted by press photographers.
Large-format photography is not limited to film; large digital camera backs are available to fit large-format cameras. These are either medium-format digital backs adapted to fit large-format cameras (sometimes resulting in cropped images), step and repeat Multishot systems, or scanning backs (which scan the image area in the manner of a flat-bed scanner). Scanning backs can take seconds or even minutes to capture an image. When using a Sinar Macroscan unit and 54H data files, over 1 GB of data can be captured.
Large format, both film-based and digital, is still used for many applications, for example: landscape photography, advertising photos, fine-art photography, scientific applications and generally for images that will be enlarged to a high magnification while requiring a high level of detail.
In the printing industry, very large fixed cameras were also used to make large films for the preparation of lithographic plates before computer to film and computer to plate techniques were introduced.
Image file formats are standardized means of organizing and storing images. This entry is about digital image formats used to store photographic and other images; (for disk-image file formats see Disk image). Image files are composed of either pixel or vector (geometric) data that are rasterized to pixels when displayed (with few exceptions) in a vector graphic display. The pixels that constitute an image are ordered as a grid (columns and rows); each pixel consists of numbers representing magnitudes of brightness and color.
A pinhole camera is a very simple camera with no lens and a single very small aperture. Simply explained, it is a light proof box with a small hole in one side. Light from a scene passes through this single point and projects an inverted image on the opposite side of the box. Cameras using small apertures and the human eye in bright light both act like a pinhole camera.
In photography, a sheet of ground glass is used for the manual focusing in some still and motion picture cameras. Some cameras have no separate viewfinder, but instead use a piece of ground glass at the focal plane to focus the scene. This type of focusing and viewing system is typically used on so-called large format cameras (cameras which use film 4×5 inches or larger). In such a camera, before the picture is taken, the ground-glass viewer is inserted in the back of the camera, and the lens opened to its widest aperture. This projects the scene on the ground glass upside down and backwards. The photographer focuses and composes using this projected image, sometimes with the aid of a magnifying glass (or loupe). In order to see the image better, a dark cloth is used to block out light, whence came the image of the old-time photographer with his head stuck under a large black cloth.
Large format, both film based and digital, is still used for many applications, for example: landscape photography, advertising photos, fine-art photography, scientific applications and generally for images that will be enlarged to a high magnification while requiring a high level of detail.
A medium format and large format camera can be heavy.
Medium format has traditionally referred to a film format in still photography and the related cameras and equipment that use this film. Generally, the term applies to film and cameras used to produce images larger than the 24 by 36 mm of 135 film, but smaller than the 4”×5” size, which is considered to be large format.
Generally, the term applies to film and cameras used to produce images larger than the 24 by 36 mm of 135 film, but smaller than the 4”×5” size, which is considered to be large format.
So medium format applies to film that is larger than 24 X 36 but smaller than 4 x 5.
In digital, medium format is currently a very expensive option, with typical brand new all digital medium format cameras retailing for $10,000 (Mamiya ZD) to $32,000 (Hasselblad H3D) in 2008, though, older and used equipment can be substantially cheaper.
Toy cameras are simple, inexpensive film box cameras made almost entirely out of plastic, often including the lens. The term is misleading, since they are not merely 'toys' but are in fact capable of taking photographs. Many were made to be given away as novelties or prizes. The Diana, an inexpensive 1960s 4x4cm novelty box camera from Hong Kong, is typically the camera most associated with the term 'toy camera'. Other cameras, such as the LOMO LC-A, Lubitel, and Holga, while originally intended as consumer, mass-market cameras, have also become identified with the term.
Friday, 26 February 2010
Eliot Porter
Eliot Porter
Eliot Porter (1901–1990) was an American photographer best known for his color photographs of nature.
Porter's reputation increased following the publication of his 1962 book, In Wildness Is the Preservation of the World. Published by the Sierra Club, the book featured Porter's color nature studies of the New England woods and quotes by Thoreau. A best seller, several editions of the book have been printed.
Porter traveled extensively to photograph ecologically important and culturally significant places. He published books of photographs from Glen Canyon (Utah), Maine, Baja California, Galápagos Islands, Antarctica, East Africa, and Iceland. Cultural studies included Mexico, Egypt, China, Czechoslovakia, and ancient Greek sites.
Eliot Porter (1of2)
2
isle of man mansions
Eliot Porter (1901–1990) was an American photographer best known for his color photographs of nature.
Porter's reputation increased following the publication of his 1962 book, In Wildness Is the Preservation of the World. Published by the Sierra Club, the book featured Porter's color nature studies of the New England woods and quotes by Thoreau. A best seller, several editions of the book have been printed.
Porter traveled extensively to photograph ecologically important and culturally significant places. He published books of photographs from Glen Canyon (Utah), Maine, Baja California, Galápagos Islands, Antarctica, East Africa, and Iceland. Cultural studies included Mexico, Egypt, China, Czechoslovakia, and ancient Greek sites.
Eliot Porter (1of2)
2
isle of man mansions
Alfred Stieglitz
Alfred Stieglitz (January 1, 1864 – July 13, 1946) was an American photographer and modern art promoter who was instrumental over his fifty-year career in making photography an accepted art form. In addition to his photography, Stieglitz is known for the New York art galleries that he ran in the early part of the 20th century, where he introduced many avant-garde European artists to the U.S. He was married to painter Georgia O'Keeffe.
Alfred Stieglitz - Early Work / Pictorialism
While Stieglitz was recuperating he had corresponded with photographer Eva Watson-Schütze, who urged him to use his influence to put together an exhibition that would be judged solely by photographers. Until that time all photographic exhibitions had been juried by painters and other types of artists, many of whom knew little about photography and its technical characteristics. Ever since the 1898 Munich exhibit Stieglitz had hoped to create a similar collective of artistically-minded photographers in the U.S., and with Watson-Schütze's urging he felt the time was right to bring a group of his friends together for the purposes of creating an exhibit to be judged solely by photographers. Stieglitz began looking for a location to hold such an exhibit, and in December 1901 he was invited by Charles De Kay of the National Arts Club to put together an exhibition.
Within two months Stieglitz had assembled a collection of prints from a close circle of his friends, which, in homage to the Munich photographers, he called the Photo-Secession. Stieglitz had full control over the selection of prints for the show, and by putting it together Stieglitz was not only declaring a secession from the general artistic restrictions of the era but specifically from the official oversight of the Camera Club The show opened at the Arts Club in early March 1902, and it was an immediate success. He had achieved his dream of putting together an exhibit judged solely by photographers (in this case, himself), and both the Arts Club members and the public responded with critical acclaim.
Invigorated by positive responses he received, he began formulating a plan for his next big move – to publish a completely independent magazine of pictorial photography to carry forth the same artistic standards of the Photo-Secessionist. By July he had fully resigned as editor of Camera Notes, and one month later he published a prospectus for a new journal he called Camera Work. He was determined it would be "the best and most sumptuous of photographic publications", and from the start it lived up to his ideals. The first issue was printed only four months later, in December 1902, and like all of the subsequent issues it contained beautiful hand-pulled photogravures, critical writings on photography, aesthetics and art, and reviews and commentaries on photographers and exhibitions.
Stieglitz was such a perfectionist that he advanced the art of photogravure printing by demanding such high standards for the prints in Camera Work. The visual quality of the gravures was so high that when a set of prints failed to arrive for a Photo-Secession exhibition in Brussels, a selection of gravures from the magazine was hung instead. Most viewers assumed they were looking at the original photographs.
Throughout 1903 Stieglitz worked at a feverish pace to publish Camera Work according to his very high standards while pursuing multiple opportunities to exhibit his own work and put together shows of the Photo-Secessionists. He was, without exaggeration, while dealing with the stresses of his home life. Although he brought on the same three associate editors he had at Camera Notes to assist with Camera Work (Dalleft Fuguet, Joseph Keiley and John Francis Strauss), he refused to let the smallest details pass without personally approving them. Later he said that he alone individually wrapped and mailed some 35,000 copies of Camera Work over the course of its publication.
By 1904 Stieglitz was once again mentally and physically exhausted. Badly needing a rest he decided to take his family to Europe in May, but in typical Stieglitz fashion he planned a grueling schedule of exhibitions, meetings and excursions. He collapsed almost upon arrival in Berlin, where he spent more than a month recuperating. He spent much of the rest of 1904 photographing Germany while his family visited their relations there. On his way back to the U. S. Stieglitz stopped in London and held a series of meetings with the leaders of the Linked Ring. He had hoped to convince them to set up a chapter of their organization in America (with Stieglitz as the director), but the membership there feared that Stieglitz would soon become their de facto leader. Before he could change their minds, he once again took ill and had to return to the U.S. without accomplishing his ambition.
He returned to more turmoil among his colleagues, with new factions competing to take on Stieglitz as the primary spokesperson for photography in America. By good fortune, while he was gone his friend Edward Steichen had returned to New York from Paris and was living in a small apartment on Fifth Avenue. He noticed that some rooms across from him were empty and thought they would be an ideal place to exhibit a small number of photographs. At first Stieglitz was not interested, but Steichen convinced him that, like Camera Work, this would be something that Stieglitz alone would control. Within a few months Stieglitz had secured the lease, assembled a collection of photographs and published an announcement about the new exhibition. On 25 November 1905 the Little Galleries of the Photo-Secession opened with one hundred prints by thirty-nine photographers. The gallery became an instant success, with almost fifteen thousand visitors during its first season and, more importantly, print sales that totaled nearly $2,800. Work by his friend Steichen accounted for more than half of those sales.
Stieglitz now had four full-time jobs at once, not including his family, and as usual he devoted himself to all but his family with seemingly boundless energy. Emmy, who had never given up thinking she would one day earn Stieglitz's love, continued giving him an allowance from her inheritance in spite of his on-going neglect. Her support allowed him to work without having to be overly concerned about financial matters, and through the combination of his jobs he became an even more relentless advocate for photography as an independent art form.
He became convinced that the only way photography would be seen as an equal to other art was for it to be placed in the same standing as other art – to be exhibited and published directly next to painting, sculpture, drawings and prints. He sensed that the public had already embraced artistic photography as a legitimate art form, and that even the Photo-Secession, which he had created, was now a part of the accepted culture. In the October 1906 issue of Camera Work his friend Joseph Keiley summed up these feelings: "Today in America the real battle for which the Photo-Secession was established has been accomplished – the serious recognition of photography as an additional medium of pictorial expression. While many people would have been happy to have realized a goal as significant as this, Stieglitz, always the iconoclast, began looking for something to rattle this growing complacency.
Stieglitz, hoping to capitalize on the popularity of the show, took photographs of her art work and issued a separate portfolio of his platinum prints of her work. The success of her show marked a turning point between the old era of Stieglitz as revolutionary promoter of photography and new era of Stieglitz as revolutionary promoter of modern art.
During the course of his long career, Stieglitz produced more than 2,500 mounted photographs. After his death O’Keeffe committed to assembling the best and most complete set of his photographs, selecting in most cases what she considered to be only the finest print of each image he made. In some cases she included slightly different versions of the same image, and these series are invaluable for their insights about Stieglitz's aesthetic composition.
In 1936 Stieglitz returned briefly to his photographic roots by mounting the one of the first exhibitions of photos by Ansel Adams in New York City. He also put on one of the first shows of Eliot Porter's work two years later.
isle of man mansions
Alfred Stieglitz - Early Work / Pictorialism
While Stieglitz was recuperating he had corresponded with photographer Eva Watson-Schütze, who urged him to use his influence to put together an exhibition that would be judged solely by photographers. Until that time all photographic exhibitions had been juried by painters and other types of artists, many of whom knew little about photography and its technical characteristics. Ever since the 1898 Munich exhibit Stieglitz had hoped to create a similar collective of artistically-minded photographers in the U.S., and with Watson-Schütze's urging he felt the time was right to bring a group of his friends together for the purposes of creating an exhibit to be judged solely by photographers. Stieglitz began looking for a location to hold such an exhibit, and in December 1901 he was invited by Charles De Kay of the National Arts Club to put together an exhibition.
Within two months Stieglitz had assembled a collection of prints from a close circle of his friends, which, in homage to the Munich photographers, he called the Photo-Secession. Stieglitz had full control over the selection of prints for the show, and by putting it together Stieglitz was not only declaring a secession from the general artistic restrictions of the era but specifically from the official oversight of the Camera Club The show opened at the Arts Club in early March 1902, and it was an immediate success. He had achieved his dream of putting together an exhibit judged solely by photographers (in this case, himself), and both the Arts Club members and the public responded with critical acclaim.
Invigorated by positive responses he received, he began formulating a plan for his next big move – to publish a completely independent magazine of pictorial photography to carry forth the same artistic standards of the Photo-Secessionist. By July he had fully resigned as editor of Camera Notes, and one month later he published a prospectus for a new journal he called Camera Work. He was determined it would be "the best and most sumptuous of photographic publications", and from the start it lived up to his ideals. The first issue was printed only four months later, in December 1902, and like all of the subsequent issues it contained beautiful hand-pulled photogravures, critical writings on photography, aesthetics and art, and reviews and commentaries on photographers and exhibitions.
Stieglitz was such a perfectionist that he advanced the art of photogravure printing by demanding such high standards for the prints in Camera Work. The visual quality of the gravures was so high that when a set of prints failed to arrive for a Photo-Secession exhibition in Brussels, a selection of gravures from the magazine was hung instead. Most viewers assumed they were looking at the original photographs.
Throughout 1903 Stieglitz worked at a feverish pace to publish Camera Work according to his very high standards while pursuing multiple opportunities to exhibit his own work and put together shows of the Photo-Secessionists. He was, without exaggeration, while dealing with the stresses of his home life. Although he brought on the same three associate editors he had at Camera Notes to assist with Camera Work (Dalleft Fuguet, Joseph Keiley and John Francis Strauss), he refused to let the smallest details pass without personally approving them. Later he said that he alone individually wrapped and mailed some 35,000 copies of Camera Work over the course of its publication.
By 1904 Stieglitz was once again mentally and physically exhausted. Badly needing a rest he decided to take his family to Europe in May, but in typical Stieglitz fashion he planned a grueling schedule of exhibitions, meetings and excursions. He collapsed almost upon arrival in Berlin, where he spent more than a month recuperating. He spent much of the rest of 1904 photographing Germany while his family visited their relations there. On his way back to the U. S. Stieglitz stopped in London and held a series of meetings with the leaders of the Linked Ring. He had hoped to convince them to set up a chapter of their organization in America (with Stieglitz as the director), but the membership there feared that Stieglitz would soon become their de facto leader. Before he could change their minds, he once again took ill and had to return to the U.S. without accomplishing his ambition.
He returned to more turmoil among his colleagues, with new factions competing to take on Stieglitz as the primary spokesperson for photography in America. By good fortune, while he was gone his friend Edward Steichen had returned to New York from Paris and was living in a small apartment on Fifth Avenue. He noticed that some rooms across from him were empty and thought they would be an ideal place to exhibit a small number of photographs. At first Stieglitz was not interested, but Steichen convinced him that, like Camera Work, this would be something that Stieglitz alone would control. Within a few months Stieglitz had secured the lease, assembled a collection of photographs and published an announcement about the new exhibition. On 25 November 1905 the Little Galleries of the Photo-Secession opened with one hundred prints by thirty-nine photographers. The gallery became an instant success, with almost fifteen thousand visitors during its first season and, more importantly, print sales that totaled nearly $2,800. Work by his friend Steichen accounted for more than half of those sales.
Stieglitz now had four full-time jobs at once, not including his family, and as usual he devoted himself to all but his family with seemingly boundless energy. Emmy, who had never given up thinking she would one day earn Stieglitz's love, continued giving him an allowance from her inheritance in spite of his on-going neglect. Her support allowed him to work without having to be overly concerned about financial matters, and through the combination of his jobs he became an even more relentless advocate for photography as an independent art form.
He became convinced that the only way photography would be seen as an equal to other art was for it to be placed in the same standing as other art – to be exhibited and published directly next to painting, sculpture, drawings and prints. He sensed that the public had already embraced artistic photography as a legitimate art form, and that even the Photo-Secession, which he had created, was now a part of the accepted culture. In the October 1906 issue of Camera Work his friend Joseph Keiley summed up these feelings: "Today in America the real battle for which the Photo-Secession was established has been accomplished – the serious recognition of photography as an additional medium of pictorial expression. While many people would have been happy to have realized a goal as significant as this, Stieglitz, always the iconoclast, began looking for something to rattle this growing complacency.
Stieglitz, hoping to capitalize on the popularity of the show, took photographs of her art work and issued a separate portfolio of his platinum prints of her work. The success of her show marked a turning point between the old era of Stieglitz as revolutionary promoter of photography and new era of Stieglitz as revolutionary promoter of modern art.
During the course of his long career, Stieglitz produced more than 2,500 mounted photographs. After his death O’Keeffe committed to assembling the best and most complete set of his photographs, selecting in most cases what she considered to be only the finest print of each image he made. In some cases she included slightly different versions of the same image, and these series are invaluable for their insights about Stieglitz's aesthetic composition.
In 1936 Stieglitz returned briefly to his photographic roots by mounting the one of the first exhibitions of photos by Ansel Adams in New York City. He also put on one of the first shows of Eliot Porter's work two years later.
isle of man mansions
Pictorialism
Pictorialism is the name given to a photographic movement in vogue from around 1885 following the widespread introduction of the dry-plate process. It reached its height in the early years of the 20th century, and declined rapidly after 1914 after the widespread emergence of Modernism.
Pictorialism largely subscribed to the idea that art photography needed to emulate the painting and etching of the time. Most of these pictures were black & white or sepia toned. Among the methods used were soft focus, special filters and lens coatings, heavy manipulation in the darkroom, and exotic printing processes.
Despite the aim of artistic expression, the best of such photographs paralleled the impressionist style then current in painting. Looking back from the present day, we can also see close parallel between the composition and picturesque subject of genre paintings and the bulk of pictorialist photography. An American circle of photographers later renounced pictorialism altogether and went on to found Group f/64, which espoused the ideal of unmanipulated, or straight photography.
Isle of Man Mansions
One of the most important publications that promoted Pictorialism was Alfred Stieglitz's "Camera Work" 1903 - 1917. Each publication had up to 12 plates that were reproduced in Photogravure, Halftone or Collotype. These plates are now collected and very sought after in the art world. Most of the photographers that made up the issues were members of the Photo-Secession, a group that promoted photography as art and soon moved away from the ideals of pictorialism.
Pictorialism largely subscribed to the idea that art photography needed to emulate the painting and etching of the time. Most of these pictures were black & white or sepia toned. Among the methods used were soft focus, special filters and lens coatings, heavy manipulation in the darkroom, and exotic printing processes.
Despite the aim of artistic expression, the best of such photographs paralleled the impressionist style then current in painting. Looking back from the present day, we can also see close parallel between the composition and picturesque subject of genre paintings and the bulk of pictorialist photography. An American circle of photographers later renounced pictorialism altogether and went on to found Group f/64, which espoused the ideal of unmanipulated, or straight photography.
Isle of Man Mansions
One of the most important publications that promoted Pictorialism was Alfred Stieglitz's "Camera Work" 1903 - 1917. Each publication had up to 12 plates that were reproduced in Photogravure, Halftone or Collotype. These plates are now collected and very sought after in the art world. Most of the photographers that made up the issues were members of the Photo-Secession, a group that promoted photography as art and soon moved away from the ideals of pictorialism.
Modernism
Modernism, in its broadest definition, is modern thought, character, or practice. More specifically, the term describes both a set of cultural tendencies and an array of associated cultural movements, originally arising from wide-scale and far-reaching changes to Western society in the late nineteenth and early twentieth centuries. The term encompasses the activities and output of those who felt the "traditional" forms of art, architecture, literature, religious faith, social organization and daily life were becoming outdated in the new economic, social and political conditions of an emerging fully industrialized world.
Modernism rejected the lingering certainty of Enlightenment thinking, and also that of the existence of a compassionate, all-powerful Creator. This is not to say that all modernists or modernist movements rejected either religion or all aspects of Enlightenment thought, rather that modernism can be viewed as a questioning of the axioms of the previous age.
Group f/64
Group f/64 was a group of seven 20th century San Francisco photographers who shared a common photographic style characterized by sharp-focused and carefully framed images seen through a particularly Western (U.S.) viewpoint. In part, they formed in opposition to the Pictorialist photographic style that had dominated much of the early 1900s, but moreover they wanted to promote a new Modernist aesthetic that was based on precisely exposed images of natural forms and found objects.
isle of man mansions
isle of man mansions
Thursday, 25 February 2010
Depth of field increases with higher number of aperture
For a given format size, at moderate subject distances, DOF is approximately determined by the subject magnification and the lens f-number. For a given f-number, increasing the magnification, either by moving closer to the subject or using a lens of greater focal length, decreases the DOF; decreasing magnification increases DOF. For a given subject magnification, increasing the f-number (decreasing the aperture diameter) increases the DOF; decreasing f-number decreases DOF.
The higher the f number the higher the depth of field. Landscape photographers like a high depth of field. As there is not always much point in a landscape photo where some of the photo is blurred.
A good way to rember is that Ansel Adams tha great landscape photogrpaher created a club called f /64. This was a high f number with great depth of field with max definition.
By having a high f number you need a longer shutter speed.
He wanted a great pictures. Adams was an admirer of Alfred Stieglitz and Paul Strand.
Many lenses for small- and medium-format cameras include scales that indicate the DOF for a given focus distance and f-number; the 35 mm lens in the image above is typical. That lens includes distance scales in feet and meters; when a marked distance is set opposite the large white index mark, the focus is set to that distance. The DOF scale below the distance scales includes markings on either side of the index that correspond to f-numbers; when the lens is set to a given f-number, the DOF extends between the distances that align with the f-number markings.
Isle of Man Mansions
isle of man
The higher the f number the higher the depth of field. Landscape photographers like a high depth of field. As there is not always much point in a landscape photo where some of the photo is blurred.
A good way to rember is that Ansel Adams tha great landscape photogrpaher created a club called f /64. This was a high f number with great depth of field with max definition.
By having a high f number you need a longer shutter speed.
He wanted a great pictures. Adams was an admirer of Alfred Stieglitz and Paul Strand.
Many lenses for small- and medium-format cameras include scales that indicate the DOF for a given focus distance and f-number; the 35 mm lens in the image above is typical. That lens includes distance scales in feet and meters; when a marked distance is set opposite the large white index mark, the focus is set to that distance. The DOF scale below the distance scales includes markings on either side of the index that correspond to f-numbers; when the lens is set to a given f-number, the DOF extends between the distances that align with the f-number markings.
Isle of Man Mansions
isle of man
Wednesday, 24 February 2010
Tuesday, 23 February 2010
Notes from lectures
Cones for detail
Rods for less light
Eye components
Iris, Lens, retina
Eye needed for long duration
Red wavelengths larger so used for long distance warning.
We need of light
Finer the task the more illumination is required.
fovea
Human eye lens can change its shape and flattens when there is dim light.
Quality and Quantity of light is important.
Environment is affected.
Artificial illumination is affected by ;
Type of source used
Environment
Quality of light depends
glare,
diffusion,
direction,
composition,
distribution
Quantity of light flux from lamp
sped of retinal impression
Discrimination of brightness
Nervous Muscular tension
Fatigue of ocular muscles can reduce ability to see in detail.
normalcy of heart rate
normal rate of reading
max rate of reading
how precise task is
performance in demonstration in visual task
experience in daylight
1000 increase not make a difference
visual acuity
contrast sensitivity 100 ft candles
ability to distinguish increases with llumination
nervous muscular tension reduces for 10ft candles
to 500 ft candles
rate if blinking needed
after reading for an hour
Blinking reduces as 1 - 100 foot candles.
So blinking rate reduces with increased illumination
Cone nerve cells used for micro vision
decrease in convergence much lower for 100 ft candles.
So nervous muscular tension increases with low illumination
Recommend illumination levels
Black thread on black cloth 800 foot candles
newspaper stock equation need 100 ft candle
typing on dark blue paper 80
Telephone directory 60
newspaper text 40
Great printing 8
visual acuity
visual efficiency
visual speed
visual health
what is acuity
distinguish detail depending on brightness of object
characteristics of light entering eye
1 foot 1000 ft lamberts 95% accuracy
Requirements to get good visual acuity depends ion good illumination but beyond a certain point there is saturation.
visual acuity is better when there is brighter surround.
Speed v brightness
80% white background not much increase in speed with increase in brightness
Grey background benefited for increase in brightness
Age decay
decrease in pupil size
visual acuity reduces
elasticity of pupil
flexibility of optic lens
Illumination needed to increase with age.
Monochromatic light is best for distinguish images.
red green and blue can create all colours.
chromatic aberration
blue can be sensed fastest green slowest
for good visibility brightness of of surround should be greater than 10,0 ft
Acuity is ability to distinguishes details depends on on brightness of object, characters iof light entering eye contrast maintained
combination of colours reduces acuity known as chromatic aberration
http://isleofmanmansions.blogspot.com/
Rods for less light
Eye components
Iris, Lens, retina
Eye needed for long duration
Red wavelengths larger so used for long distance warning.
We need of light
Finer the task the more illumination is required.
fovea
Human eye lens can change its shape and flattens when there is dim light.
Quality and Quantity of light is important.
Environment is affected.
Artificial illumination is affected by ;
Type of source used
Environment
Quality of light depends
glare,
diffusion,
direction,
composition,
distribution
Quantity of light flux from lamp
sped of retinal impression
Discrimination of brightness
Nervous Muscular tension
Fatigue of ocular muscles can reduce ability to see in detail.
normalcy of heart rate
normal rate of reading
max rate of reading
how precise task is
performance in demonstration in visual task
experience in daylight
1000 increase not make a difference
visual acuity
contrast sensitivity 100 ft candles
ability to distinguish increases with llumination
nervous muscular tension reduces for 10ft candles
to 500 ft candles
rate if blinking needed
after reading for an hour
Blinking reduces as 1 - 100 foot candles.
So blinking rate reduces with increased illumination
Cone nerve cells used for micro vision
decrease in convergence much lower for 100 ft candles.
So nervous muscular tension increases with low illumination
Recommend illumination levels
Black thread on black cloth 800 foot candles
newspaper stock equation need 100 ft candle
typing on dark blue paper 80
Telephone directory 60
newspaper text 40
Great printing 8
visual acuity
visual efficiency
visual speed
visual health
what is acuity
distinguish detail depending on brightness of object
characteristics of light entering eye
1 foot 1000 ft lamberts 95% accuracy
Requirements to get good visual acuity depends ion good illumination but beyond a certain point there is saturation.
visual acuity is better when there is brighter surround.
Speed v brightness
80% white background not much increase in speed with increase in brightness
Grey background benefited for increase in brightness
Age decay
decrease in pupil size
visual acuity reduces
elasticity of pupil
flexibility of optic lens
Illumination needed to increase with age.
Monochromatic light is best for distinguish images.
red green and blue can create all colours.
chromatic aberration
blue can be sensed fastest green slowest
for good visibility brightness of of surround should be greater than 10,0 ft
Acuity is ability to distinguishes details depends on on brightness of object, characters iof light entering eye contrast maintained
combination of colours reduces acuity known as chromatic aberration
http://isleofmanmansions.blogspot.com/
Monday, 22 February 2010
Sunday, 21 February 2010
Thursday, 18 February 2010
Notes from lecture on 3 illumination engineering
Eye and visions
Instructional objectives
1. Identify Similarity between eye and camera system
State nervous system use for adaption of eye.
List factors for good lighting
Define glare
Incandescent, phosphorescence, Fluorescence,
Colour temperature is categorized by colour temperature
Iris, focusing lens, retina
Iris
resembles a camera in structure and action
Iris is like the shutter
Lens of eye is like the lens of a camera which focuses lens
Retina is like film
Optical image is formed on retina. Nerves enable us to see.
Crystalline Lens
Optic nerve.
Iris is a diaphram that regulates light entering eye by expanding and contradicting pupil.
Crystaline lens is more flexible than camera lens. It can be convex flat,
is is controlled by cilliary muscles
Screen is retina.
Fovea most acute sport of vision where fine detailed is formed
Rest of retina takes care of orientation.
Communicates through optic nerves
Double nerves
Rods - Dim Light Night vision
Cones - Concentrated in central region known as fovea
Cones decreases from fovea
they do form colour, sensitivity,
Photopic cone cells
discriminate fines details
critical observation
dense pack
Cone cell vision does not work below 0.01 ft lamberts
Foot Lambert is is amount of light falling on surface area defined as sum involving 1 candle.
So cone cells are not sensitive below certain levels of foot Lamberts.
Two sets of nerves cones and rods
Scotopic vision (rods)
Takes over when light vision less than 0.01 ft lamberts
No or little colour discrimination
Quite grey in appearance
sees as silhouettes
Shift from rod to cone is purkinjee effect.
Unlike camera which is rigid.
Upon increase in intensity of illumination
decrease in pupil size and greater detail with cone cells.
pupil diameter 1.2 - 2 mm.
Eye functions under varying illumination by changing pupil size and verve system.
Pupil size
Large Dim light rod
Small bright cone
do not get detail with rods
Eye unconsciously takes care of this.
Human eye is chromatic dispersive power
near vision easily focus blue
strenuous red
Far vision easily focus red
strenuous on blue
Pupil opening
Large Flattest shape distance object can focus on red
Small convex shape near objects easy to focus on blue as it has short test wave length,.
At about 1m from eye no difference in accommodation.
can focus on all colors equally.
cones better at longer wavelengths than rods.
rods best at 507 nm blue green
cones 550
seeing is primary purpose of lighting
must see artificial light is as close to natural light.
prevent defective vision.
Artificial lighting extend out activity period.
Visibility of object will depend on size of object,
details of object, level of illumination.
Contrast or color in brightness has an impact.
The ways eyes function need observation time.
size of object illumination requirement,
deficiency must be compensated
visibility will depend on nature of eye defects.
Fatigue physical or optical.
distraction.
Depends in nature of defects.
Every man made system has fatigue.
Eye fatigue
Retinal, muscular,
Glare, due to brightness some might not see board due to glare due to bright light,
Glare means intense illumination in plane.
when you have to move focus, you cause muscular adjustments.
Glare causing strain and fatigue on muscles on eye.
After a full days work pupil is dilated.
We are now involved in many eye tasks.
Need a break to offset fatigue.
weekend offsets fatigue of working week.
Pupilliary changes must not become permanent if so will nedd glasses
Eye defects known due to age, use and abuse.
Reading fine prints in dim light can abuse eye.
Strained muscles will occur due to difference in size images.
refractory errors.
So lower retinal sensibility needs more illumination.
Countless impression formed on retina.
photopic - cones
scotopic - rods
fine image details need good cone vision.
lens becomes convex when you want to observe fine detail.
Human eye is achromatic in nature.
cone cells better 550nm yellowish green hue
good lighting should aim to prevent defects in vision.
visibility depends on efficacy of individual
Visible range of light 380nm to 700nm
arc lamp emits selective radiations in visible zone
isle of man mansions
Instructional objectives
1. Identify Similarity between eye and camera system
State nervous system use for adaption of eye.
List factors for good lighting
Define glare
Incandescent, phosphorescence, Fluorescence,
Colour temperature is categorized by colour temperature
Iris, focusing lens, retina
Iris
resembles a camera in structure and action
Iris is like the shutter
Lens of eye is like the lens of a camera which focuses lens
Retina is like film
Optical image is formed on retina. Nerves enable us to see.
Crystalline Lens
Optic nerve.
Iris is a diaphram that regulates light entering eye by expanding and contradicting pupil.
Crystaline lens is more flexible than camera lens. It can be convex flat,
is is controlled by cilliary muscles
Screen is retina.
Fovea most acute sport of vision where fine detailed is formed
Rest of retina takes care of orientation.
Communicates through optic nerves
Double nerves
Rods - Dim Light Night vision
Cones - Concentrated in central region known as fovea
Cones decreases from fovea
they do form colour, sensitivity,
Photopic cone cells
discriminate fines details
critical observation
dense pack
Cone cell vision does not work below 0.01 ft lamberts
Foot Lambert is is amount of light falling on surface area defined as sum involving 1 candle.
So cone cells are not sensitive below certain levels of foot Lamberts.
Two sets of nerves cones and rods
Scotopic vision (rods)
Takes over when light vision less than 0.01 ft lamberts
No or little colour discrimination
Quite grey in appearance
sees as silhouettes
Shift from rod to cone is purkinjee effect.
Unlike camera which is rigid.
Upon increase in intensity of illumination
decrease in pupil size and greater detail with cone cells.
pupil diameter 1.2 - 2 mm.
Eye functions under varying illumination by changing pupil size and verve system.
Pupil size
Large Dim light rod
Small bright cone
do not get detail with rods
Eye unconsciously takes care of this.
Human eye is chromatic dispersive power
near vision easily focus blue
strenuous red
Far vision easily focus red
strenuous on blue
Pupil opening
Large Flattest shape distance object can focus on red
Small convex shape near objects easy to focus on blue as it has short test wave length,.
At about 1m from eye no difference in accommodation.
can focus on all colors equally.
cones better at longer wavelengths than rods.
rods best at 507 nm blue green
cones 550
seeing is primary purpose of lighting
must see artificial light is as close to natural light.
prevent defective vision.
Artificial lighting extend out activity period.
Visibility of object will depend on size of object,
details of object, level of illumination.
Contrast or color in brightness has an impact.
The ways eyes function need observation time.
size of object illumination requirement,
deficiency must be compensated
visibility will depend on nature of eye defects.
Fatigue physical or optical.
distraction.
Depends in nature of defects.
Every man made system has fatigue.
Eye fatigue
Retinal, muscular,
Glare, due to brightness some might not see board due to glare due to bright light,
Glare means intense illumination in plane.
when you have to move focus, you cause muscular adjustments.
Glare causing strain and fatigue on muscles on eye.
After a full days work pupil is dilated.
We are now involved in many eye tasks.
Need a break to offset fatigue.
weekend offsets fatigue of working week.
Pupilliary changes must not become permanent if so will nedd glasses
Eye defects known due to age, use and abuse.
Reading fine prints in dim light can abuse eye.
Strained muscles will occur due to difference in size images.
refractory errors.
So lower retinal sensibility needs more illumination.
Countless impression formed on retina.
photopic - cones
scotopic - rods
fine image details need good cone vision.
lens becomes convex when you want to observe fine detail.
Human eye is achromatic in nature.
cone cells better 550nm yellowish green hue
good lighting should aim to prevent defects in vision.
visibility depends on efficacy of individual
Visible range of light 380nm to 700nm
arc lamp emits selective radiations in visible zone
isle of man mansions
Wednesday, 17 February 2010
Lecture-3 Eye and Vision I
Lecture-3 Eye and Vision I
A lecture from the Department of Electrical Engineering, IIT Kharagpur.
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isle of man houses
A lecture from the Department of Electrical Engineering, IIT Kharagpur.
isle of man mansions blog
isle of man houses
Tuesday, 16 February 2010
Ideas from lecture on illumination engineering
Instructional Objectives
Lecture
Radiation
State visible range of light
State range of light human eyes respond too and
define UV radiation and IR radiation
More than 80% of info is through light
Use optimum resources at economic prices.
Need electrical power system
Need AC in nature
Light is that radiant Energy
that provides visual sensation for eyes
It is akin to radiant hears but with different wavelengths and freuquencies
visible light spans 180nm
Nanometres
to 500 nm
Human eye
So you can see 700nm red
Can see violet colour 200nm
red to violet 700 - 380 nm
Relative Energy
Visible spectrum 380 nm 800nm
500 - 600 nanometres is in the green yellow region.
Ultra violet is light below 300 nm
300 metres per micro second.
Ultra Violet
ultra Violet - Visual spectrum - Infra Red
Infra red lamps can be used to hear rooms.
can be used for drying heating, and lightening photos.
UV is used for germicidal applications.
Relative luminosity
Ability of eye to respond
400nm is quite low repsonse form human eye
The MAX response of human eye is to green yellow zone.
Artificial sources
Incandescent lamps are some of the foremost uses of artificial light,.
Gas discharge lights. Discontinuous lights. They radiate light at specific frequencies.
Spectral energy
relative energy, luminosity Nanometres
The sun is more our less through the spectrum.
The blue sky peaks art 440
The eye responds most to 550 nanometres. This means the blue sky peaks at 440 nm but the eye is less bale to respond so the energy is of no use.
Incandescent bodies give out radiation that is maintained at higher temperatures.
Yet you do not want evaporation of filament material.
Physical processes that enable us to have artificial sources
Incandescence. Thermo luminescene depends on radiation temperature
Incandescent lamp
Gas Lamps
Candles
Oil
Luminous output is standardized at candelas.
Continuous spectrum
All modern way is to get similar continuous spectrum
at economic and optimum resources.
Term to remember
electro luminescence produces line spectrum
this is a chemical or electrical action on gas vapour that leads
to light radiation
this produces Colour depends on material employed.
line spectrum not continuous spectrum.
fluorescence lamps is most used source of light next to incandescent
There is photoluminescence.
Radiation is absorbed at one wavelength then radiates another wavelength.
If a material can absorb at one wavelength and radiate another,
then this is fluorescence it absorbs at one wavelength and
radiates in visual spectrum, absorbs UV radiation.
zinc , uranium,
Phosphorescene Energy absorbed at one wavelength then radiates later.
use paints that contain calcium.
Radiation after exposure to light.
Phosphorescene Does not require original source of light once exposed to light it slowly radiates.
fluorescence is right away.
Good lighting uses combination of luminescence and fluorescence.
intensity depends on kind of gas used.
Central is that radiation temperatures an important issue.
Black body is one that
is not transparent does not reflect
but absorbs all energy
Energy radiated is proportional to temperature high temperature higher output,
Sun temp at 550nm.
90 lumens per watt.
for most sources lumens per watt of energy consumed.
for 4000k the spectral max 100nm.
higher temperature high is relative max energy.
6500 - 7000 k 43 % if visible energy
occurrence of max at different levels is called displacement.
Grey Body
Energy radiated at each wavelength is less than that is in the case of black body.
So it reflects a certain % of energy at each wavelength.
Carbon filament lamp is a grey body.
selective raidators they radiate less total energy compared to a black body but does radiate more energy at certain wavelengths.
colour temperature is temperature at which black body must be heated to match colour.
Blue sky 25,000 k
Florescent lamp is 4500 k
500 w day light 5000k
extreme blue sky can be matched 1 daylights fluorescent lamp.
500 watt daylight lamp does not match bright sunlight.
light is radiant energy that provides visual energy.
incandescence - Continuous spectrum Lower efficiency
Luminescence -
fluorescence -
Phosphorescence -
Power loss is inversely proportional to operating voltage.
Luminescence is light that usually occurs at low temperatures, and is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light generated by high temperatures. Historically, radioactivity was thought of as a form of "radioluminescence", although it is today considered to be separate since it involves more than electromagnetic radiation.
he following are types of luminescence
isle of man mansions
Lecture
Radiation
State visible range of light
State range of light human eyes respond too and
define UV radiation and IR radiation
More than 80% of info is through light
Use optimum resources at economic prices.
Need electrical power system
Need AC in nature
Light is that radiant Energy
that provides visual sensation for eyes
It is akin to radiant hears but with different wavelengths and freuquencies
visible light spans 180nm
Nanometres
to 500 nm
Human eye
So you can see 700nm red
Can see violet colour 200nm
red to violet 700 - 380 nm
Relative Energy
Visible spectrum 380 nm 800nm
500 - 600 nanometres is in the green yellow region.
Ultra violet is light below 300 nm
300 metres per micro second.
Ultra Violet
ultra Violet - Visual spectrum - Infra Red
Infra red lamps can be used to hear rooms.
can be used for drying heating, and lightening photos.
UV is used for germicidal applications.
Relative luminosity
Ability of eye to respond
400nm is quite low repsonse form human eye
The MAX response of human eye is to green yellow zone.
Artificial sources
Incandescent lamps are some of the foremost uses of artificial light,.
Gas discharge lights. Discontinuous lights. They radiate light at specific frequencies.
Spectral energy
relative energy, luminosity Nanometres
The sun is more our less through the spectrum.
The blue sky peaks art 440
The eye responds most to 550 nanometres. This means the blue sky peaks at 440 nm but the eye is less bale to respond so the energy is of no use.
Incandescent bodies give out radiation that is maintained at higher temperatures.
Yet you do not want evaporation of filament material.
Physical processes that enable us to have artificial sources
Incandescence. Thermo luminescene depends on radiation temperature
Incandescent lamp
Gas Lamps
Candles
Oil
Luminous output is standardized at candelas.
Continuous spectrum
All modern way is to get similar continuous spectrum
at economic and optimum resources.
Term to remember
electro luminescence produces line spectrum
this is a chemical or electrical action on gas vapour that leads
to light radiation
this produces Colour depends on material employed.
line spectrum not continuous spectrum.
fluorescence lamps is most used source of light next to incandescent
There is photoluminescence.
Radiation is absorbed at one wavelength then radiates another wavelength.
If a material can absorb at one wavelength and radiate another,
then this is fluorescence it absorbs at one wavelength and
radiates in visual spectrum, absorbs UV radiation.
zinc , uranium,
Phosphorescene Energy absorbed at one wavelength then radiates later.
use paints that contain calcium.
Radiation after exposure to light.
Phosphorescene Does not require original source of light once exposed to light it slowly radiates.
fluorescence is right away.
Good lighting uses combination of luminescence and fluorescence.
intensity depends on kind of gas used.
Central is that radiation temperatures an important issue.
Black body is one that
is not transparent does not reflect
but absorbs all energy
Energy radiated is proportional to temperature high temperature higher output,
Sun temp at 550nm.
90 lumens per watt.
for most sources lumens per watt of energy consumed.
for 4000k the spectral max 100nm.
higher temperature high is relative max energy.
6500 - 7000 k 43 % if visible energy
occurrence of max at different levels is called displacement.
Grey Body
Energy radiated at each wavelength is less than that is in the case of black body.
So it reflects a certain % of energy at each wavelength.
Carbon filament lamp is a grey body.
selective raidators they radiate less total energy compared to a black body but does radiate more energy at certain wavelengths.
colour temperature is temperature at which black body must be heated to match colour.
Blue sky 25,000 k
Florescent lamp is 4500 k
500 w day light 5000k
extreme blue sky can be matched 1 daylights fluorescent lamp.
500 watt daylight lamp does not match bright sunlight.
light is radiant energy that provides visual energy.
incandescence - Continuous spectrum Lower efficiency
Luminescence -
fluorescence -
Phosphorescence -
Power loss is inversely proportional to operating voltage.
Luminescence is light that usually occurs at low temperatures, and is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light generated by high temperatures. Historically, radioactivity was thought of as a form of "radioluminescence", although it is today considered to be separate since it involves more than electromagnetic radiation.
he following are types of luminescence
- Bioluminescence, by a living organism
- Chemoluminescence, resulting of a chemical reaction
- Electrochemiluminescence, by an electrochemical reaction
- Crystalloluminescence, produced during crystallization
- Electroluminescence, in response to an electric current passed through it
- Cathodoluminescence, where beam of electrons impacts on a luminescent material such as a phosphor
- Mechanoluminescence, resulting from any mechanical action on a solid
- Triboluminescence, generated when bonds in a material are broken when that material is scratched, crushed, or rubbed
- Fractoluminescence, generated when bonds in certain crystals are broken by fractures
- Piezoluminescence, produced by the action of pressure on certain solids
- Photoluminescence, absorption of photons causing re-radiation of photons
- Phosphorescence, delayed re-radiation
- Fluorescence, where the emitted photons are of lower energy than those absorbed
- Radioluminescence, produced in a material by the bombardment of ionizing radiation
- Sonoluminescence, from imploding bubbles in a liquid when excited by sound
- Thermoluminescence, when absorbed light is re-emitted on heating.
isle of man mansions
Monday, 15 February 2010
Pictures About Rain - Foto Dedicate alla Pioggia
Pictures About Rain - Foto Dedicate alla Pioggia
isle of man mansions
It is difficult to take photos in the rain. You need to get the raindrops and they are often too small and fast. Sometimes rain can get in your camera and wreck it leaving the lens cloudy. This can even break a camera permanently or temporarily. Bring a cover. If it gets wet let the camera dry.
Often you take a picture in the rain you see the raindrops sparkle in the sun or fall intensely yet when you see the photo there is no rain on the photo.
But rain can allow interesting composition.
Some like to photos droplets, reflections get close up to something the rain is hitting as often you can see the rain then. Get action shots of people moving with umbrellas in the rain.
The best photographers can get photos in the rain, But I still need to develop.
It is one of the true tests of a photographer but above all keep the camera safe from getting wet.
-
isle of man mansions
It is difficult to take photos in the rain. You need to get the raindrops and they are often too small and fast. Sometimes rain can get in your camera and wreck it leaving the lens cloudy. This can even break a camera permanently or temporarily. Bring a cover. If it gets wet let the camera dry.
Often you take a picture in the rain you see the raindrops sparkle in the sun or fall intensely yet when you see the photo there is no rain on the photo.
But rain can allow interesting composition.
Some like to photos droplets, reflections get close up to something the rain is hitting as often you can see the rain then. Get action shots of people moving with umbrellas in the rain.
The best photographers can get photos in the rain, But I still need to develop.
It is one of the true tests of a photographer but above all keep the camera safe from getting wet.
-
Sunday, 14 February 2010
Colour temperature in photography
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. The temperature is conventionally stated in units of absolute temperature, kelvin (K). Color temperature is related to Planck's law and to Wien's displacement law.
Higher color temperatures (5,000 K or more) are cool (blueish white) colors; lower color temperatures (2,700–3,000 K) are warm (yellowish white through red) colors.
In physics, a black body is an idealized object that absorbs all electromagnetic radiation that falls on it. No electromagnetic radiation passes through it and none is reflected. Because no light (visible electromagnetic radiation) is reflected or transmitted, the object appears black when it is cold. However, a black body emits a temperature-dependent spectrum of light. This thermal radiation from a black body is termed black-body radiation.
So colour temp is the key.
Isle of man mansions
Higher color temperatures (5,000 K or more) are cool (blueish white) colors; lower color temperatures (2,700–3,000 K) are warm (yellowish white through red) colors.
In physics, a black body is an idealized object that absorbs all electromagnetic radiation that falls on it. No electromagnetic radiation passes through it and none is reflected. Because no light (visible electromagnetic radiation) is reflected or transmitted, the object appears black when it is cold. However, a black body emits a temperature-dependent spectrum of light. This thermal radiation from a black body is termed black-body radiation.
So colour temp is the key.
Isle of man mansions
Polarion HID Searchlights
Polarion HID Searchlights
This company make powerful searchlights. I do not know if they can be used for photography.
This company make powerful searchlights. I do not know if they can be used for photography.
Lecture - 2 Instructional Objectives
Lecture - 2 Instructional Objectives
Another lecture on Illumination engineering.
Need to know about balanced and unbalanced loads in photography.
Line voltage us the The voltage provided by a power line at the point of use.
Load balancing (electrical power), the storing of excess electrical power by power stations during low demand periods, for release as demand rises
Unbalanced loads -
Each phase has a different impedance. So loads can be balanced and unbalanced.
Distribution through Overground cables or underground cables.
Urban by underground wires rural by overground
isle of man mansions ;
Another lecture on Illumination engineering.
Need to know about balanced and unbalanced loads in photography.
Line voltage us the The voltage provided by a power line at the point of use.
Load balancing (electrical power), the storing of excess electrical power by power stations during low demand periods, for release as demand rises
Unbalanced loads -
Each phase has a different impedance. So loads can be balanced and unbalanced.
Distribution through Overground cables or underground cables.
Urban by underground wires rural by overground
isle of man mansions ;
Saturday, 13 February 2010
antipodes
In geography, the antipodes (from Greek ἀντίποδες, from anti- "opposed" and pous "foot"; pronounced /ænˈtɪpəˌdiːz/) of any place on Earth is the point on the Earth's surface which is diametrically opposite to it. Two points that are antipodal to one another are connected by a straight line running through the centre of the Earth.
http://isleofmanfarmsforsale.blogspot.com/
http://isleofmanfarmsforsale.blogspot.com/
Term to use in illuminance photography
Term to use in illuminance photography
In geometry, two lines or planes (or a line and a plane), are considered perpendicular (or orthogonal) to each other if they form congruent adjacent angles (an L-shape). The term may be used as a noun or adjective. Thus, referring to Figure 1, the line AB is the perpendicular to CD through the point B. Note that by definition, a line is infinitely long, and strictly speaking AB and CD in this example represent line segments of two infinitely long lines. Hence the line segment AB does not have to intersect line segment CD to be considered perpendicular lines, because if the line segments are extended out to infinity, they would still form congruent adjacent angles.
In geometry, two figures are congruent if they have the same shape and size. More formally, two sets of points are called congruent if, and only if, one can be transformed into the other by an isometry, i.e., a combination of translations, rotations and reflections.
Mathematics Intersecting at or forming right angles.
In geometry, two lines or planes (or a line and a plane), are considered perpendicular (or orthogonal) to each other if they form congruent adjacent angles (an L-shape). The term may be used as a noun or adjective. Thus, referring to Figure 1, the line AB is the perpendicular to CD through the point B. Note that by definition, a line is infinitely long, and strictly speaking AB and CD in this example represent line segments of two infinitely long lines. Hence the line segment AB does not have to intersect line segment CD to be considered perpendicular lines, because if the line segments are extended out to infinity, they would still form congruent adjacent angles.
In geometry, two figures are congruent if they have the same shape and size. More formally, two sets of points are called congruent if, and only if, one can be transformed into the other by an isometry, i.e., a combination of translations, rotations and reflections.
Mathematics Intersecting at or forming right angles.
Some terms to remember for lecture on Illumination engineering
In mathematics, the root mean square (abbreviated RMS or rms), also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity. It is especially useful when variates are positive and negative, e.g., sinusoids.
Periodic Signals are signals that repeat themselves after a certain amount of time. More formally, a function f(t) is periodic if f(t + T) = f(t) for some T and all t. The classic example of a periodic function is sin(x) since sin(x + 2 π) = sin(x). However, we do not restrict attention to sinusoidal functions.
Sinusoidal voltage is rms. Root Mean Sqaure
The generation of AC electric power is commonly three phase, in which the waveforms of three supply conductors are offset from one another by 120°. The design of the power generators has three sets of coils placed 120 degrees apart rotating in a magnetic field. This creates three separate sine waves of electricity that are displaced from each other in time by 120 degrees of rotation (1/3 of a circle). Standard frequencies of rotation are either 50 Hertz (cycles per second) in Europe or 60 Hertz in North America.
Electric Maintenance Fundamentals - AC/DC Theory
When we can get electrons to flow away from their atom in a single direction we have electricity.
Silver , glass, aluminum good conductors.
Insulator plastic, dry wood, rubber
turning crank on generator forces electrons through conductor.
Periodic Signals are signals that repeat themselves after a certain amount of time. More formally, a function f(t) is periodic if f(t + T) = f(t) for some T and all t. The classic example of a periodic function is sin(x) since sin(x + 2 π) = sin(x). However, we do not restrict attention to sinusoidal functions.
Sinusoid
The quintessential periodic waveform. These can be either Sine functions, or Cosine Functions.
Square Wave
The square wave is exactly what it sounds like: a series of rectangular pulses spaced equidistant from each other, each with the same amplitude.
Triangle Wave
The triangle wave is also exactly what it sounds like: a series of triangles. These triangles may touch each other, or there may be some space in between each wavelength.
Easy way to express
Sinusoidal voltage is rms. Root Mean Sqaure
Periodic signal one that is repeated after certain amount of time.
single phase ac generation
Electronics/Magnetic Field
The generation of AC electric power is commonly three phase, in which the waveforms of three supply conductors are offset from one another by 120°. The design of the power generators has three sets of coils placed 120 degrees apart rotating in a magnetic field. This creates three separate sine waves of electricity that are displaced from each other in time by 120 degrees of rotation (1/3 of a circle). Standard frequencies of rotation are either 50 Hertz (cycles per second) in Europe or 60 Hertz in North America.
Electric Maintenance Fundamentals - AC/DC Theory
When we can get electrons to flow away from their atom in a single direction we have electricity.
Silver , glass, aluminum good conductors.
Insulator plastic, dry wood, rubber
turning crank on generator forces electrons through conductor.
Introduction to Illumination Engineering
Introduction to Illumination Engineering
Points raised
Need for good illumination
radiation and colour
eye and visions
laws of illumination
different entities of illumination system,
lights sources
luminaries
environment and glare
If you can not measure it, you can not improve it
When you can measure what you are speaking about, and express it in numbers
Illumination design
interior lighting
Exterior lighting
functionality - security purposes.
Different type of loads and individual protection
take precautions for fire
emergency supplies
uses of illumination engineering in other areas of science and life
Physiology and psychology play a part in illumination engineering
people depend on light
activities was restrictiveness to sunset and sunrise
Artificial light increases this
visions acquires 80% of info
Artificial light
Sunlight - moon light
Artificial light should be functional, pleasant
different light needed for different purposes
Physiology is the science of the functioning of living systems.
characteristic of or promoting normal, or healthy, functioning
sources may need to be multiple they need to be economic, energy efficient,
how is electricity supplied.
Is it ac or dc
any current flow requires closed circuit,
losses exist in power lines,
reduce losses
i2r
i is line current
r is line resistance
longer line higher resistance
power stations are far from load centres
losses minimized by supplying higher voltages
electric current dc or ac
isle of man mansions
Points raised
Need for good illumination
radiation and colour
eye and visions
laws of illumination
different entities of illumination system,
lights sources
luminaries
environment and glare
If you can not measure it, you can not improve it
When you can measure what you are speaking about, and express it in numbers
Illumination design
interior lighting
Exterior lighting
functionality - security purposes.
Different type of loads and individual protection
take precautions for fire
emergency supplies
uses of illumination engineering in other areas of science and life
Physiology and psychology play a part in illumination engineering
people depend on light
activities was restrictiveness to sunset and sunrise
Artificial light increases this
visions acquires 80% of info
Artificial light
Sunlight - moon light
Artificial light should be functional, pleasant
different light needed for different purposes
Physiology is the science of the functioning of living systems.
characteristic of or promoting normal, or healthy, functioning
sources may need to be multiple they need to be economic, energy efficient,
how is electricity supplied.
Is it ac or dc
any current flow requires closed circuit,
losses exist in power lines,
reduce losses
i2r
i is line current
r is line resistance
longer line higher resistance
power stations are far from load centres
losses minimized by supplying higher voltages
electric current dc or ac
isle of man mansions
Friday, 12 February 2010
Lumens
The lumen (symbol: lm) is the SI unit of luminous flux, a measure of the power of light perceived by the human eye. Luminous flux differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. The lumen is defined in relation to the candela by
That is, a light source that uniformly radiates one candela in all directions radiates a total of 4π lumens. If the source were partially covered by an ideal absorbing hemisphere, that system would radiate half as much luminous flux—only 2π lumens. The luminous intensity would still be one candela in those directions that are not obscured.
A single fluorescent light fixture that produces a luminous flux of 12000 lumens might light a residential kitchen with an illuminance of 500 lux. Lighting a larger area to the same illuminance requires a proportionately greater number of lumens.
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light.
Units
The SI unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. In other systems of units, luminous flux may have units of power.
Weighting
The luminous flux accounts for the sensitivity of the eye by weighting the power at each wavelength with the luminosity function, which represents the eye's response to different wavelengths. The luminous flux is a weighted sum of the power at all wavelengths in the visible band. Light outside the visible band does not contribute. The ratio of the total luminous flux to the radiant flux is called the luminous efficacy.
The lux (symbol: lx) is the SI unit of illuminance and luminous emittance. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface. It is analogous to the radiometric unit watts per square metre, but with the power at each wavelength weighted according to the luminosity function, a standardized model of human visual brightness perception. In English, lux is used in both singular and plural.
Explanation
Lux is a derived unit based on lumen, and lumen is a derived unit based on candela.
One lux is equal to one lumen per square metre, where 4π lumens is the total luminous flux of a light source of one candela of luminous intensity:
1 lx = 1 lm·m-2 = 1 cd·sr·m–2.
As with other SI units, SI prefixes can be used, for example a kilolux (klx) is 1,000 lux.
Illuminance Example
10−5 lux Light from Sirius, the brightest star in the night sky[2]
10−4 lux Total starlight, overcast sky
0.002 lux Moonless clear night sky with airglow
0.01 lux Quarter moon
0.27 lux Full moon on a clear night
1 lux Full moon overhead at tropical latitudes[4]
3.4 lux Dark limit of civil twilight under a clear sky[5]
50 lux Family living room
80 lux Hallway/toilet
100 lux Very dark overcast day
320–500 lux Office lighting
400 lux Sunrise or sunset on a clear day.
1,000 lux Overcast day; typical TV studio lighting
10,000–25,000 lux Full daylight (not direct sun)
32,000–130,000 lux Direct sunlight
Unicode has a symbol for "lx":, but this is just a legacy code to accommodate old code pagesAsian languages, and it is not recommended for use in any language today. in certain
Lux versus lumen
The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. A flux of 1,000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1,000 lux. However, the same 1,000 lumens, spread out over ten square metres, produces a dimmer illuminance of only 100 lux.
Achieving an illuminance of 500 lux might be possible in a home kitchen with a single fluorescent light fixture with an output of 12,000 lumens. To light a factory floor with dozens of times the area of the kitchen would require dozens of such fixtures. Thus, lighting a larger area to the same level of lux requires a greater number of lumens.
So a lumen is The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread.
So a luminous flux is power of light. It is different from radiant flux in that it measures light sensitivity to human eye.A single fluorescent light fixture that produces a luminous flux of 12000 lumens might light a residential kitchen with an illuminance of 500 lux. Lighting a larger area to the same illuminance requires a proportionately greater number of lumens.
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of light emitted, in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light.
Units
The SI unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. In other systems of units, luminous flux may have units of power.
Weighting
The luminous flux accounts for the sensitivity of the eye by weighting the power at each wavelength with the luminosity function, which represents the eye's response to different wavelengths. The luminous flux is a weighted sum of the power at all wavelengths in the visible band. Light outside the visible band does not contribute. The ratio of the total luminous flux to the radiant flux is called the luminous efficacy.
The lux (symbol: lx) is the SI unit of illuminance and luminous emittance. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface. It is analogous to the radiometric unit watts per square metre, but with the power at each wavelength weighted according to the luminosity function, a standardized model of human visual brightness perception. In English, lux is used in both singular and plural.
Explanation
Lux is a derived unit based on lumen, and lumen is a derived unit based on candela.
One lux is equal to one lumen per square metre, where 4π lumens is the total luminous flux of a light source of one candela of luminous intensity:
1 lx = 1 lm·m-2 = 1 cd·sr·m–2.
As with other SI units, SI prefixes can be used, for example a kilolux (klx) is 1,000 lux.
Illuminance Example
10−5 lux Light from Sirius, the brightest star in the night sky[2]
10−4 lux Total starlight, overcast sky
0.002 lux Moonless clear night sky with airglow
0.01 lux Quarter moon
0.27 lux Full moon on a clear night
1 lux Full moon overhead at tropical latitudes[4]
3.4 lux Dark limit of civil twilight under a clear sky[5]
50 lux Family living room
80 lux Hallway/toilet
100 lux Very dark overcast day
320–500 lux Office lighting
400 lux Sunrise or sunset on a clear day.
1,000 lux Overcast day; typical TV studio lighting
10,000–25,000 lux Full daylight (not direct sun)
32,000–130,000 lux Direct sunlight
Unicode has a symbol for "lx":, but this is just a legacy code to accommodate old code pagesAsian languages, and it is not recommended for use in any language today. in certain
Lux versus lumen
The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread. A flux of 1,000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance of 1,000 lux. However, the same 1,000 lumens, spread out over ten square metres, produces a dimmer illuminance of only 100 lux.
Achieving an illuminance of 500 lux might be possible in a home kitchen with a single fluorescent light fixture with an output of 12,000 lumens. To light a factory floor with dozens of times the area of the kitchen would require dozens of such fixtures. Thus, lighting a larger area to the same level of lux requires a greater number of lumens.
So a lumen is The difference between the lux and the lumen is that the lux takes into account the area over which the luminous flux is spread.
The SI unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. In other systems of units, luminous flux may have units of power.
lm is is one unit of luminous flux.
Luminous flux is often used as an objective measure of the useful power emitted by a light source, and is typically reported on the packaging for light bulbs, although it is not always prominent. Energy conscious consumers commonly compare the luminous flux of different light bulbs since it provides an estimate of the apparent amount of light the bulb will produce, and is useful when comparing the luminous efficacy of incandescent and compact fluorescent bulbs.
If a light source emits one candela of luminous intensity uniformly across a solid angle of one steradian, its total luminous flux emitted into that angle is one lumen. Alternatively, an isotropic one-candela light source emits a total luminous flux of exactly 4π lumens. The lumen can be thought of casually as a measure of the total "amount" of visible light in some defined beam or angle, or emitted from some source. The number of candelas or lumens from a source also depends on its spectrum, via the nominal response of the human eye as represented in the luminosity function.
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foot-candle (=10.76 lx)
phot (=10 klx)
nox (=1 mlx)SI photometry units
Quantity Symbol SI unit Abbr. Notes
Luminous energy Qv lumen second lm·s units are sometimes called talbots
Luminous flux F lumen (= cd·sr) lm also called luminous power
Luminous intensity Iv candela (= lm/sr) cd an SI base unit
Luminance Lv candela per square metre cd/m2 units are sometimes called "nits"
Illuminance Ev lux (= lm/m2) lx Used for light incident on a surface
Luminous emittance Mv lux (= lm/m2) lx Used for light emitted from a surface
Luminous efficacy
lumen per watt lm/W ratio of luminous flux to radiant flux
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. This is a subjective attribute/property of an object being observed.
Lecture - 6 Photometry
Sunday, 7 February 2010
Photos people like of food
What people like to see in terms of photos of food
French Fries 100
White background
Close up some show whole meal but some show a close up with only part of food shown.
Some show chips being fried
White background or with other food.
Scampi 11
Individual scampi on a fork close up
Blue background full plate with other stuff
No white background this time.
All either on a plate with other stuff or close up- on fork
Ham 10
On white background full view
close up with other food
cheese
Wind and cheese popular
different types of cheese
bacon
With other stuff on white background
On own on white background
A smiley face
One I could do Infront of a mirror with other stuff
sausage
Mostly on featureless background white black,
BBQ
fork close up
scone
scone with jam white background
dry scones close up no need to see background
on plate set tea set
close up no background needed
hot chocolate
ripple of hot chocolate
swirl
woolen mitten gloves round drink
background tends to black or white
isle of man luxury villa
So ideas
on plate with other items
Fork close up
close up do not have to see all meal
French Fries 100
White background
Close up some show whole meal but some show a close up with only part of food shown.
Some show chips being fried
White background or with other food.
Scampi 11
Individual scampi on a fork close up
Blue background full plate with other stuff
No white background this time.
All either on a plate with other stuff or close up- on fork
Ham 10
On white background full view
close up with other food
cheese
Wind and cheese popular
different types of cheese
bacon
With other stuff on white background
On own on white background
A smiley face
One I could do Infront of a mirror with other stuff
sausage
Mostly on featureless background white black,
BBQ
fork close up
scone
scone with jam white background
dry scones close up no need to see background
on plate set tea set
close up no background needed
hot chocolate
ripple of hot chocolate
swirl
woolen mitten gloves round drink
background tends to black or white
isle of man luxury villa
So ideas
on plate with other items
Fork close up
close up do not have to see all meal
Thursday, 4 February 2010
Photography Lighting & Equipment Tips : How to Position Lights for Photography
Photography Lighting & Equipment Tips : How to Position Lights for Photography
http://isleofmanmansions.blogspot.com/
http://isleofmanmansions.blogspot.com/
Tuesday, 2 February 2010
Soft light
Soft light refers to light that tends to "wrap" around objects, casting shadows with soft edges. The softness of the light depends mostly on the following two factors:
Distance. The closer the light source, the softer it becomes.
Size of light source. The larger the source, the softer it becomes.
The softness of a light source can also be determined by the angle between the illuminated object and the 'length' of the light source (the longest dimension that is perpendicular to the object being lit). The larger this angle is, the softer the light source.
Overexposure and underexposure
A photograph may be described as overexposed when it has a loss of highlight detail, that is, when the bright parts of an image are effectively all white, known as blown out highlights (or clipped whites). A photograph may be described as underexposed when it has a loss of shadow detail, that is, the dark areas indistinguishable from black, known as blocked up shadows (or sometimes crushed shadows, crushed blacks, or clipped blacks, especially in video). As the image to the right shows, these terms are technical ones rather than artistic judgments; an overexposed or underexposed image may be "correct", in that it provides the effect that the photographer intended.
isle of man luxury villa
isle of man luxury villa
exposure value
In photography, exposure value (EV) denotes all combinations of camera shutter speed and relative aperture that give the same exposure. The concept was developed in Germany in the 1950s, in an attempt to simplify choosing among combinations of equivalent camera settings. Exposure value also is used to indicate an interval on the photographic exposure scale, with 1 EV corresponding to a standard power-of-2 exposure step, commonly referred to as a “stop”.
Exposure value was originally indicated by the quantity symbol Ev; this symbol continues to be used in ISO standards, but the acronym EV is now more common elsewhere.
Although all camera settings with the same exposure value nominally give the same exposure, they do not necessarily give the same picture. The exposure time (“shutter speed”) determines the amount of motion blur, as illustrated by the two images at the right, and the relative aperture determines the depth of field.
H = Et
H is Photometric Exposure
E is Image Plane illuminance
t is Exposure time
isle of man mansions
The Theory of Exposure
The Theory of Exposure
isle of man mansions
Difference in one f stop is different to one f stop in shutter speed then
isle of man mansions
Difference in one f stop is different to one f stop in shutter speed then
Single Light Studio Portrait Photography : White Cards in Single Light Studio Photography
Single Light Studio Portrait Photography : White Cards in Single Light Studio Photography
isle of man mansions
isle of man mansions
Monday, 1 February 2010
Photometry
Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy (including light) in terms of absolute power; rather, in photometry, the radiant power at each wavelength is weighted by a luminosity function (a.k.a. visual sensitivity function) that models human brightness sensitivity. Typically, this weighting function is the photopic sensitivity function, although the scotopic function—and others—may also be applied in the same way.
http://isleofmanmansions.blogspot.com/
http://isleofmanmansions.blogspot.com/
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