The Internet Age of Photojournalists

In the face of the impact of online media, which combines the advantages of newspapers, radio and television, it has become a top priority for "traditional" photographers to quickly change their concepts, improve their own quality and adapt to the needs of picture communication under the new situation. Photographers in the network age should improve their quality from the following aspects. The first human understanding of imaging began in the 4th century BC. As early as the Spring and Autumn Period and the Warring States Period, Mo Zhai, a Chinese thinker and representative of Mohism, had discovered pinhole imaging. He recorded his discovery in the Book of Mohism: a small hole was opened in the wall of a dark hut, and the scenery outside the hole would hang upside down on the wall opposite the hole in the sun. Mozi not only discovered this phenomenon, but also explained it scientifically. He thinks that light travels in a straight line like an arrow. For example, when a person stands outside the house, the light on his head shines under the wall through the small hole, while the light on his feet shines on the wall through the small hole, so the figure is upside down. This is the earliest record of the principle of straight-line propagation of light. Mozi discovered pinhole imaging 2000 years earlier than Europe.

1 1 century, an Arab scholar named Alha Zan explained the solar eclipse in detail, which became the research clue of European scholar Bacon. In16th century, Bacon discovered that the solar eclipse could be observed through pinhole imaging, and it was not dazzling. However, the image formed through the small hole is opposite to the image directly observed by the naked eye. His findings were published in the form of charts in the book Cosmic Light and Space Geometry published by Dutch doctor and mathematician Prisons in 1545.

Before that, Cesa Cesali Liano, a student of the great Renaissance artist Leonardo da Vinci, had written Pinhole Imaging Theory in his edition of Architecture 152 1, and his theory benefited from the influence of Leonardo da Vinci.

By the middle of16th century, due to the invention of convex lens, people began to use convex lens instead of pinhole. They found that the images made by convex lenses were much brighter than those made by small holes, and they also removed lizards.

1558, a scientist in Naples, Baltar, introduced an auxiliary painting tool called CameraObscure in his book The Magic of Science. With this device, even people who can't draw can draw easily, as long as they draw the image through the convex lens with a pencil. Later, cardano, a physicist in Milan, strongly recommended this kind of black box and modified it. This black box has been used by the great German astronomer Képler 1920.

/kloc-in the middle of the 0/7th century, this black box was improved to miniaturization. 1657 Schott, a teaching professor at the University of Bilsburg, introduced a portable black box in his book Optical Magic, which consists of two boxes, one large and one small, and the focal length is adjusted by controlling the expansion and contraction of the box.

1676, in his book "Experiment and Curiosity", Srurm, a professor of mathematics at Adolf University, advocated adding a 45-degree reflector on the black box, and adding a transparent glass above the black box, which can be used for painting. 1685, the friar zahn of Beersburg further improved this small reflective black box, making it more and more widely used until19th century.

From the end of 18 to the beginning of 19, Renaissance painters used it extensively. This is of great help for painters to intuitively grasp the relationship between perspective, distance and size, and also creates conditions for the invention of photography.

In the18th century, the use of black boxes has become a common fashion among intellectuals, and all papers related to optics or painting have various discussions on the use and improvement of black boxes. By the beginning of19th century, the development of black boxes has become a trend. Just like modern cameras, all kinds of black boxes are all over Europe and all over the world. The collection in the French Museum of Photography mentioned earlier has a large number of black boxes representing this era. This kind of camera continued to the Gaelic people. 19th century ago, although people invented all kinds of black boxes, they were only used as auxiliary tools for painting, and they still could not "take pictures" in the modern sense. In other words, you can't put some kind of "photosensitive" material in the black box and record the image. But photography originated from this kind of "painting with light", so that the word photography in English consists of the prefix "Photo-" and the suffix "-photography".

Since the beginning of18th century, people have been trying to think about how to repair the images made by black boxes. From 65438 to 0725, Schultz, a professor of anatomy at Adolf University, discovered that silver salt (a photosensitive chemical that we still use) can turn black after being exposed to light, and use it to form a glyph image, but this image disappeared shortly after seeing the light. Swedish chemist Scheler and Swiss librarian Seneby successively developed Schultz's theory, which played an indelible role in the final birth of photography. At this point, it has reached the end of 18.

1800, Wedgwood, the son of a British ceramic worker, put opaque leaves on leather coated with silver nitrate and exposed them to the sun. As a result, the leather irradiated by light turned dark black, while the unexposed place under the leaves left a white shadow of the leaves. Wedgwood called this image "the picture of the sun". This may be the earliest "exposure" experiment in the world. However, like many previous experiments, the sunshine picture experiment finally failed, because those unexposed white leaves and shadows still have a sense of light, and they all turn black quickly when they are seen under the light.

The first person in the world who successfully repaired the image made by the black box was Nipps, a retired French officer. 18 16, Nipps also made the "first" black-and-white negative image on paper (black-and-white image is just the opposite of the image seen, equivalent to the current negative). The same fate as Wedgwood is that this black-and-white negative image has not been preserved due to continuous exposure.

It's19th century1920s. Nips wants to get a positive image on the metal plate (black and white is the same as the image he saw) so that it can be printed on white paper with ink after etching. After many experiments, he finally coated a layer of oil-soluble white asphalt on a lead-tin alloy plate. He put the metal plate in a black box and aimed the camera at the pigeon shed outside his studio window for eight hours. Lightweight asphalt has hardened. At this time, he took out the metal plate from the black box, put it in lavender oil, and washed away the uncured white asphalt. In this way, the bright part of the image turned white, but the bright part did not show the black metal plate background, and a black and white front "photo" was successfully taken. Nipps called his method "the shadow technique". Nipps's photo of pigeon shed taken by sunlight photography is recognized as the first photo in the world. This photo was taken at 1826. But the birth of photography didn't start from this day, because the sensitivity of Nipps's sunlight photography is too low, and it has no practical value. Later, after improvement, it was adopted by the printing plate making at that time.

Nowadays, the birth of photography is recognized by people, starting with the silver plate photography in Daguerre in 1839. Louis Daguerre (1787- 185 1), a French landscape painter and stage designer, was a famous French artist at that time. He worked with Nipps for a long time. Daguerre first painted carefully with a camera box in Charn style. When he learned about Nipps's sunshine photography, he communicated with Nips and cooperated with him to explore new photography methods. But Nipps didn't agree with Daguerre's idea and made further experiments with silver salt. Therefore, until the death of Nipps, sunshine photography has not been fundamentally improved. Until 1837, Daguerre had formed a whole set of new experimental methods, which completely improved the photography technology.

1838, Daguerre fumigated a silver-plated copper plate with iodine vapor in a darkroom to produce a layer of silver iodide on its surface. Silver iodide is one of the silver salts we use at present (silver salt is also called silver halide, including silver chloride, silver bromide and silver iodide). It has photosensitive properties and will decompose into silver when it sees light. He exposed the copper plate coated with silver iodide in a black Schott box for about 15 minutes, then took out the copper plate and fumigated it on mercury vapor again. The image taken after exposure has been enhanced and appeared, but the image at this time can not be watched, otherwise the above-mentioned "tragedy" will repeat itself. Therefore, the image at this time is called "latent image". The above process is equivalent to our modern "development". Finally, the image is fixed with sodium sulfite (sodium sulfate soda), that is, unexposed silver iodide is dissolved. This process is equivalent to our modern "repair". All the above processes must be carried out in a darkroom or a special developing cassette. The copper plate after development and fixation is finally washed with distilled water, so a "photo" is formed. Daguerre called his photography method "Daguerre photography", and modern people call Daguerre photography method "silver plate photography".

Due to financial problems, Daguerre can't continue to improve his photography. Through various efforts, his invention attracted the attention of the French government and won the national subsidy award. In order to repay the government's concern, Daguerre made public all its technical patents in 1839 and gave them to the people free of charge. Therefore, the birth of photography can be traced back to 1839.

Shortly after the invention of Daguerre's silver disc photography, it quickly spread all over Europe and was improved many times. Photography in Daguerre has promoted the development of technology, industry, tourism and railway transportation in Europe.

While in Daguerre, Talbot, a British landlord and amateur scientist, made a similar attempt in photography. He coated silver chloride on paper as a photosensitive material, then immersed the exposed silver chloride paper in concentrated brine to prevent the image from further blackening, and finally exposed the negative image on another photosensitive paper by light to form a positive image. Only Talbot didn't apply for a patent at that time, which made his photography method not spread. Talbot's photography method is called Carlo photography.

After Daguerre, most European countries and major cities in the United States set up portrait studios. These studios are called "Daguerre-style studios". It took about 1 minute to take a photo of Daguerre. Due to the development of photography in Daguerre, both the camera manufacturing industry and the photosensitive material manufacturing industry have developed rapidly. Most of the old cameras mentioned at the beginning of the article are products around this period.

/kloc-In the 1950s of 0/9, photography experienced another great change, and a photography method called Corcaud Dion photography or wet plate photography became popular all over the world. This method is more complicated than Daguerre photography and Carlo photography, but it attracted more people's interest, so it spread quickly and lasted for a long time.

Daguerre photography is expensive because of silver-plated copper plate, and Carlo photography is obviously cheap, but because the negative used to "copy" the positive image is opaque, the image is not clear. So people try to coat silver chloride on glass as a negative. But we need to find an adhesive to make silver chloride firmly adhere to the glass, otherwise it will be easily washed away by water. So people began to think of using egg white as adhesive, but the photosensitive chemicals that can be mixed in egg white are limited, which affects the photosensitive sensitivity of glass negative and makes the exposure time too long.

185 1 year, it was at the peak of the British industrial revolution that a London sculptor discovered a viscous liquid called "collodion", which can be used as an ideal adhesive for photosensitive materials. This collodion is made by dissolving nitrocellulose in ether and alcohol. It is mixed with photosensitive drugs and coated on glass. After exposure, put it in a camera for exposure. Immediately after exposure, developing, fixing and developing are carried out, thus producing a glass negative.

The "dry plate" and film representing modern photography are 19 after the 1970s. First, from wet board to dry board.

The invention of collodion promoted the development of wet lithography and greatly shortened the exposure time. It can be said that photography in the true sense began from this period. Wet plate photography has also greatly promoted the popularization of photography, and more and more photographers have mastered this technology. In Europe and America, due to the spread of wet-plate photography technology, a portrait photography boom has been set off, and more and more photo studios have sprung up. Wet board photography has also spawned an amateur photography group, and more and more photographers have begun to contact photography. It was also during this period that a group of people who were determined to take photos appeared. They photographed a lot of natural and cultural landscapes in that period, and also photographed a lot of portraits of celebrities. These photos left a rare early photographic record for mankind.

Wet printing photography also promoted the development of photographic equipment, mainly cameras. At that time, there were two-lens stereo cameras and four-lens multi-bottom cameras.

However, wet-plate photography is too complicated, and it needs to carry a lot of auxiliary equipment and medicines when going out for photography, and there are tents used as darkrooms, which hinder the further popularization of wet-plate photography. Wet photography is an important milestone in the history of photography, but it was eventually replaced by more advanced dry photography. A, wooden rearview camera

Since Daguerre invented the silver plate photography, people began to refit the small camera box for painting into a camera with better sealing performance, which can be used to install the photosensitive plate. The original cameras were all rear-view wooden cameras with leather cavities. Because the function of drawing images horizontally is not needed, the 45-angle reflector inside the camera box is removed. This kind of camera, because the image on the back glass is particularly dark, the photographer must cover the camera with a big black cloth and only expose the camera lens when shooting. This kind of camera has been produced from 1860 to the middle of the 20th century for a long time. Until the end of the 20th century, the improved version of this camera was also being produced. In the mid-20th century, people could still see portrait photographers wearing a black cloth on their heads in photo studios. Until the 1970s, 1980s and 1990s, a large number of photographers who liked to take landscape photos with large negatives still used back-framed cameras and covered their heads with black cloth. AnselAdams, a famous American landscape photographer, is a model of taking black and white landscape photos with a back camera.

At first, the wooden background camera shot by dry plate was folded, which was not fundamentally improved compared with the wooden camera used in Daguerre period. The photographer put the dry plate in the wooden box in advance for easy carrying. Common specifications of dry board are 120× 170mm (commonly known as "1/2 board") and 85× 120mm (commonly known as "1/4 board"). Cover your head with black cloth before shooting, and focus the ground glass on the back of the viewfinder with a magnifying glass. The image on the frosted glass is upside down. Close the shutter on the lens after focusing truly, then put the dry-plate cassette on the ground glass, and remove the shading baffle in front of the cassette. At this time, you can open the shutter to shoot. Early wooden cameras used pneumatic shutters. First pull a string to wind up the shutter, then press the rubber ball with your hand and open and close the shutter with compressed gas. The opening time of the shutter is completely controlled by pressing the balloon by hand.

The lens used in the early wooden folding camera was Dagor anastigmatic lens, and the maximum aperture was only F8. Later, it was changed to three sets of "Cook" lenses, and the maximum aperture reached F4, which increased the light input by four times. Later, this kind of landline used various famous German lenses, such as Zeiss, Rodenstein, Ned, etc. However, due to the need of imaging area and axial shift, the maximum aperture of these lenses was still maintained at about F4.5 to F5.6. Until 2000, this kind of wooden folding rearview camera was still produced in China after many improvements.