Product innovation of paraxial camera

In the early days of the formation of the camera industry, hand-made camera products were mainly influenced by painting black boxes, and products with wool screen coaxial framing occupied an important position.

However, the use of rough screen framing is greatly limited. On the one hand, in the early stage of the development of photosensitive materials, enough ambient light is needed to take pictures; On the other hand, rough screen images are easily disturbed by external stray light when taking pictures, which leads to contradictions. This contradiction finally inspired the change of framing mode, and paraxial framing is the most thorough product of this change.

There were several types of early paraxial cameras. From the structure of paraxial viewfinder, the simplest one is called frame viewfinder, which can be installed on any coaxial viewfinder as an additional viewfinder.

Because the viewfinder is simple to make, its viewfinder accuracy is basically acceptable when shooting scenes at a certain distance, so the products equipped with viewfinder in early cameras are more common, such as Chambre Automatic1860 produced in France and Eka 1924 produced in France.

Another viewfinder device with lens on the basis of frame viewfinder is called Newton viewfinder, which consists of negative lens (also called concave lens) and frame. The characteristic of this viewfinder is that it can be made much smaller under the condition of obtaining the same field of view, and it is possible to get a brighter viewfinder with good lens material.

Le Pascal 1898 produced in France, Ernemann j tropical 1904 produced in Germany and Ensign Cupid 1922 produced in Britain are all cameras with Newton viewfinder.

As another kind of paraxial camera, dual-lens reflex camera appeared in the second half of19th century. Its principle is to image the scene whose optical axis is at a 90-degree angle with the reflector on the wool screen through one or a group of positive lenses (also called convex lenses), and the viewing optical path is vertical. Because the framing lens and the photographic lens are axially parallel and adjacent, the framing error is greatly improved, and this advantage is very prominent, so it is rapidly popularized.

For example, 1887 French-made Kinegraphe and 1889 German-made Krugener Simplex belong to the early products of dual-lens varieties;

At the same time, reflective viewfinder with the same principle as dual-lens reflective camera is also widely used, such as Le Royal Detectif o Ultime Special produced in Belgium in 1893 and folding mahogany Rodolphe produced in1903;

Bright viewfinder is a variant of reflective viewfinder, which was popular at the end of 19 and the first half of the 20th century.

The main difference between it and the reflective viewfinder is that it uses a positive lens instead of a wool screen, so that the spatial image of the scene can be obtained and the viewfinder becomes very bright. However, the change of eye position often affects the viewing range and often causes the feeling of eye discomfort. So later, the bright viewfinder was mainly used as an additional viewfinder. 1905 Kodak's 1 folding pocket camera is one of many products that use bright viewfinder.

This bright viewfinder, in turn, paves the way for the promotion of simple dual-lens reflex cameras.

Compound viewfinder is another milestone in the development of early paraxial viewfinder. It installs two or more paraxial viewfinders on a camera, providing a variety of viewfinder modes. The biggest feature of compound viewfinder is that it gives users more choices. For example, Newton viewfinder and bright viewfinder are combined on the camera to provide two framing methods: head-up framing and waist-down framing;

Or combine the frame viewfinder and bright viewfinder on the camera to provide the same framing requirements.

The appearance of composite framing device has certain influence on the design of advanced products in the future. For example, in 1949, the German-made Pu Lauber Makina III D evolved this classic composite framing device, although the framing technology was greatly improved during this period.

In fact, the early paraxial camera provided some necessary framing methods, and the beauty, convenience and miniaturization of the camera were later. At the beginning of the 20th century, with the continuous progress of optical technology, the development of paraxial cameras entered a new historical period. The type of optical viewfinder began to improve, and the paraxial ranging device was developed and integrated into the viewfinder. Because paraxial framing avoids the use of photographic lenses, the design of camera lenses, especially wide-angle lenses, can adopt the actual field of view angle instead of the equivalent field of view angle, thus relatively simplifying the lens structure. With the continuous maturity of paraxial framing technology, the miniaturization of cameras has gradually become a reality.

People have an experience, that is, when galileo telescope is used in reverse, you can see bright and reduced landscape images. Don't underestimate this experience. This anti-Galileo principle provides sufficient resources for the development of optical viewfinder. In fact, if a positive lens or a group of equivalent positive lenses is added to Newton viewfinder as an eyepiece, an inverse Galileo viewfinder will be formed. Of course, a reasonable inverse Galileo viewfinder needs to be recalculated. Because the inverse Galileo viewfinder is smaller and brighter, it has been widely used in cameras with various paraxial framing methods since the 1920s. Inverse Galileo viewfinder is a great revolution of optical viewfinder, which guides the development direction of optical viewfinder in the future.

The first epoch-making camera product in the 20th century was Leica, which represented the outstanding achievement of paraxial camera. When designing Leica cameras, oskar barnack focused on small, light and unique metal body and reverse Galileo viewfinder, which became an important symbol of Leica's original products.

Later, in order to meet the needs of photography, Leeds Company introduced a series of special lenses for Leica cameras and corresponding external viewfinder, which greatly expanded the application scope of Leica cameras and became a model of small cameras.

However, the inability to achieve optical ranging is still the defect of early Leica products. Therefore, it is the task of Leeds to produce suitable ranging devices. Fortunately, Leeds will soon produce a small rangefinder that can be inserted into the landscape frame.

After Leica II, the rangefinder was integrated into the fuselage. However, the independent rangefinder can still be used as an accessory, not limited by the variety of lenses.

The prestigious Zeiss company has also made outstanding achievements in the field of camera manufacturing, and its products cover a variety of specifications from dry-plate cameras to various film cameras. In order to curb the business expansion of Leica products in the field of small cameras, Zeiss has spared no effort to develop competitive products. The first targeted product is Contax I, which pioneered the speed range of1/25-11000 seconds and the metal shutter door of door B. With the fast Contax port technology and a series of lenses and accessories, Contax camera became the main force of Leica products at that time.

Subsequently, Contax II and III, whose viewfinder is equipped with linkage ranging and framing devices, came out one after another. These two cameras are excellent products in paraxial cameras, and their robustness is also quite excellent.

In particular, Contax III camera of 1936 integrated selenium exposure meter into the camera body, which was not available in Leica cameras at that time. Leica cameras can only get corresponding functions through independent exposure meters in the form of accessories.

Dual-lens reflex camera is an important branch of paraxial camera, which uses viewfinder to simulate photographic lens to capture scene images and provide visual reference close to the actual intake range.

1929 prototype laid the development direction of modern dual-lens reflex camera. However, it is not the only direction. In the 20th century, there were many amazing creations of dual-lens reflex cameras, such as 1932 Superfekta folding dual-lens reflex camera made in Germany. The design idea of this camera reflects the product designer's attitude towards aesthetics and bizarre way of thinking.

Since then, the dual-lens reflex camera with 135 film has also occupied a place in the development of small cameras. The most representative is the Kangtai Flex camera released by Zeiss at 1935, which has the experience of Contex. It not only directly adopts the longitudinal rolling shutter focal plane shutter of Contex, but also can change the lens, and there are many paraxial framing methods to choose from. The most important feature is that the most advanced selenium exposure meter was built into the fuselage at that time. This built-in exposure meter technology had a great influence on the later famous Lulai products.

In fact, if it weren't for the influence of the war, this unprecedented product might have developed more perfectly. In addition to Kangtai Flex dual-reflex cameras, other 135 dual-reflex cameras are coming out one after another. Like 1940 Meikai Ref No.2 made in Japan, this is a double-reflex camera with horizontally arranged lenses, which is quite distinctive. 1959, Germany also produced an Agfa Flexilette camera, the main structure of which is closer to that of an ordinary paraxial camera for head-up viewing.

However, not all the products of this new idea have become mainstream varieties, perhaps too many, and they are only a flash in the pan in the history of camera development.

But in any case, the paraxial camera has developed into a huge product system before the 1950s, and its specifications and types are all incomparable to coaxial cameras (including wool screen framing cameras and SLR cameras). In addition to ordinary cameras and special cameras (including spy cameras), paraxial products are also in the forefront of miniature cameras. Typical examples are 1949 Mikroma produced in Czechoslovakia and 1952 golden Ricoh "16" produced in Japan;

Copying camera is the world of paraxial products, from the imitation of books, watches and guns in the last century to the imitation of lighters and pens in this century, all show the superiority of paraxial structure. In fact, before the large-scale application of zoom lens, paraxial camera has been the mainstream product in the lighting market. Since the 1950s. 1950, the quality of Japanese cameras began to attract American attention. The New York Times published the "Nikon Camera and Lens Test Report", which reported the performance characteristics of the camera and attracted the attention of all countries in the world. This period coincides with the emergence of a large number of Japanese paraxial cameras, such as Arco35 of 1952, Mammy and Press Van of Rich Ray6 in the same year, 1953.

In fact, Japan paved the way for paraxial cameras and quickly became a new camera producer in the world. Japan's move has attracted the attention of West Germany, an old camera producer in history, which can only cope with the changes in the international market by introducing high-quality new products.

1954, when I improved various products that day, the epoch-making Leica M3 camera was published in West Germany.

M3 adopted a series of brand-new technologies, which pushed the head-up paraxial camera to a new height. For example, built-in equal brightness frame framing and parallax automatic compensation mechanism; Automatically reset the film counter; Torque type paper wrench; And the newly designed single-axis non-rotating shutter speed regulating wheel, which is characterized by not rotating when the shutter moves, and so on. The application of these new technologies provides a more comprehensive reference entity for the future development of cameras.

1957, Nikon SP camera with M3 technology came out (Figure 36). It adopts the same single-axis non-rotating shutter speed dial and exposure meter linkage mechanism as Leica M3, and an improved viewfinder device. When using lenses with different focal lengths of 28- 135, different bright frames appear in the viewfinder, which greatly facilitates users. At this point, the paraxial camera in head-up framing mode has developed to a new height.

In 1960s, the paraxial camera further developed to miniaturization and specialization. The cameras in the R&D center began to move from Germany to Japan. Japanese products take electronization as the main goal of camera development, and have popularized CdS and SPD photometry technologies, and took the lead in completing the automatic exposure function with the participation of semiconductor technology on head-up cameras, and published a large number of cameras such as Jasika Electro 35. These popular cameras have played an immeasurable role in promoting the development of the photography market.

On the other hand, professional high-end paraxial cameras such as mamia C3 stand out and form a new market structure.

In 1970s, Japan vigorously developed SLR cameras. Due to the moderate price of a considerable number of products, paraxial cameras began to lose their previous position in the civil field. Although a large number of popular head-up cameras are still available, the golden age of paraxial cameras is disappearing. The appearance and continuous improvement of the anti-Galileo viewfinder really cleared the way for the development of the paraxial camera, and the optical ranging device on the paraxial camera laid the foundation for the development of the autofocus camera. In fact, the application of semiconductor components greatly improves the automation of cameras. At first, the desk-controlled automatic exposure mechanism shone brilliantly on the paraxial camera, that is, the paraxial camera with program exposure mode appeared again. However, among all automatic modes, the most historic one is the emergence of autofocus technology.

1977, Japan's Konica C35AF camera took the lead in introducing a double-image symmetrical photoelectric focusing system, which realized the automatic focusing of the camera. The optical theory of the system comes from the dual-image focusing device on the advanced head-up camera. It reflects the image to the AF sensor through the mirrors in two ranging windows, compares the contrast of the two images, and changes the deflection position of one of the mirrors. When the contrast of the two images is completely consistent, the central system of the camera sends an instruction to the focusing server to complete the focusing. This analog autofocus theory once had an impact on the development of autofocus for SLR cameras. There have been several products similar to Chinon)CE-5 AF camera in history, which use the paraxial autofocus system on the lens to operate the lens of SLR camera and complete autofocus. It can be seen that the autofocus mode pioneered by Konica C35AF paraxial camera finally changed the appearance of the camera, and intelligence has become the main direction of camera research and development since then. The influence of SLR cameras on the market share of paraxial cameras in the 1970s is obvious. In addition to the price factor, the main reason is that paraxial cameras can't use zoom lenses like SLR cameras, which greatly reduces the convenience. After Tokyo Asahi optical co., ltd. The zoom paraxial camera was introduced in 1980s, and the anti-Galileo framing device which can continuously change the field of view was widely used in small paraxial cameras. The paraxial camera in head-up framing mode has entered the era of autofocus and electric zoom. Zoom head-up viewfinder has become the mainstream of popular products, and the sales of head-up viewfinder have also started to rebound obviously, resulting in a situation in which the market influence of SLR products and paraxial products is equally divided. The emergence of APS further stabilized this situation.

At the end of 1990s, under the guidance of traditional technology, a large number of digital cameras with head-up view mode appeared. Because this camera adopts LCD screen with monitoring function, macro photography can be easily realized. From then on, the patent of macro mode is no longer unique to SLR cameras.

More than one hundred years of camera development has proved that paraxial framing technology has its inherent advantages. Theoretically, the anti-Galileo viewfinder can be extremely miniaturized, so with the wide application of a new generation of multi-pixel sensors, the digitization of paraxial cameras has become a development trend. In the future, the paraxial camera will be gradually separated from the film and replaced by digital recording media. The camera will be smaller and thinner, and there may be a card-type paraxial camera with diverse functions, which integrates mobile phones, language translators, mobile TV and online computers. However, some high-quality SLR cameras still use film or film-type digital accessories to maintain the continuity of photography culture.