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HISTORY OF TECHNOLOGY, TECHNOLOGY, OBJECTS AROUND US
Digital camera. History of invention and production
Directory / The history of technology, technology, objects around us In 1989, the Svema factory produced the last batch of 8 mm amateur film, five years ago the last laboratory for developing this film was closed, and a little later all the necessary chemicals disappeared from the sale ... Thus, before our eyes, the era of home filming ended and the era of amateur video has come. It seems that the same fate awaits your favorite photo soon. Recent advances in the creation of high-quality and already not very expensive electronic digital cameras convince of this. Arriving at the annual meeting of classmates who have gathered from all over the country, you can get a digital camera that looks like a regular camera and take two to three dozen pictures. However, having doubts about the composition of a group shot, you can quickly decide whether to reshoot this scene. To do this, just look at the frame on the liquid crystal display built into the rear wall of the camera. And when you return home, you can remove the credit card-sized memory disk from the camera and insert it into your portable laptop to check the quality of images in full size and color on its screen. You can also edit your photos here. Lighten some, add warm tones to others, and change the scale for others. For this, a graphics processing program is used. If you wish, you can immediately send a picture to any former classmate ... The above is no longer fantasy. As a result, the photographer is left with the old skills, perhaps, only manipulations with the lens and pressing the shutter. And how could it be otherwise, if we are talking about changing the very information essence of photography - the transition from analog processes of obtaining and processing images to digital ones?
By the way, until recently such a transition did not seem inevitable even when "photochemistry" was replaced by electronics. Until very recently, many companies also considered magnetic video recording in a television format, that is, an analog process, to be quite a real technical basis for electronic photography. And they didn’t just count, but released fully functional devices on this basis. The path to the modern digital camera was a stubborn climb along a sometimes quite rocky path. The first were devices with the formation of images on a CCD matrix and subsequent analog recording on magnetic tape - like video cameras. The resulting photographs were then copied onto a special video diskette. Devices that create and store an image in a "purely computer" digital format were created in the early 1990s. They used the same elements of computers such as "lap-top" and a laptop. Made in the form of rectangular plates the size of a credit card, with connectors at the end, they are inserted into special ports of specified computers. In addition to additional memory blocks, these can be, for example, devices such as a fax modem, hard disk, sound card. The steady decline in the cost of elements and devices of digital memory with an increase in their specific capacity, the reduction in the cost of compact discs, the rapid progress in the methods of processing and compressing video files, etc. - all this finally made the digital device "basic" in this area - a computer, and not a video recorder, and not a TV. The real turning point in digital photography occurred in August 1997, when Fuijtsu Microelectronics - Fujitsu and Sierra Imaging - Sierra signed an agreement on joint development in the field of digital imaging circuitry production. Under this agreement, Fujitsu provided its family of PISC processors, and Sierra offered to develop the entire "piping" - the chipset - the "motherboard", that is, to combine all the necessary controllers, as well as development tools and provide its software (Image Expert ). In addition, Sierra has taken on the responsibility of marketing, distributing and supporting this technical solution. The joint agreement led to the creation of a complete hardware and software package for the design and implementation of digital cameras. As a result, the market for digital cameras doubled every year and by the end of the century exceeded ten million devices a year. At that time, only Sierra offered customers a single solution with all the necessary electronic components for creating digital cameras and continues to lead in this area to this day. From now on, there is no doubt that the popularity of digital cameras will grow like an avalanche. In the same way as in its time, in the 1880s, after the transition from expensive, inconvenient glass photographic plates to light and cheap photographic film, traditional photography began to rapidly conquer the masses. Today, the digital camera is not just the digital equivalent of a film camera. It can perform other functions that you would not even expect from a film camera. A digital camera is actually more like a media collector or multimedia storage medium. You can take it with you to take pictures, record sound, moving objects, even thoughts. “Take a closer look at a digital camera, and even better, open it and see what is inside it,” Oleg Tatarnikov advises in his article in Computer Press, “and you will see that it is no more a camera than a computer is a typewriter. Even the photographic potential hidden in a banal digital "soap box" can significantly exceed the capabilities of serious film cameras. Judge for yourself - the size of even a small-format frame on 24x36 mm film significantly exceeds the size of CCD matrices, and the larger the image size, the more difficult it is to develop a non-distorting lens of sufficient aperture for it. For example, most amateur digital camera CCDs have a diagonal of 1/3", or 8,5 millimeters. Therefore, "normal" (that is, equivalent to a 50 mm lens on 35 mm film cameras) for such matrix will be a lens with a focal length of only 9 millimeters.For such a lens to have a relative aperture,for example F / 2, the lens diameter should be respectively equal to 4,5 millimeters, and for a 35 mm camera - 25 millimeters. Therefore, for example, to implement a significant difference in focal length for a conventional 35 mm camera, you have to make a complex optical system with large and expensive lenses, and for digital cameras you can use a "standard" lens with a diameter of 2-4 centimeters and get as much as 20x Zoom. Feel the difference? And when shooting macro on a small matrix with the same lens, you can get a depth of field unattainable for film photography. However, in addition to all this, digital cameras have a number of other features that are more typical for computers than for cameras. In addition to the optical system, a digital camera has a control processor powerful enough to perform, among other things, complex exposure analysis and decide on a shooting mode in a tiny fraction of a second, after which the resulting image is processed. Fast data bus allows you to quickly reduce the time to readiness to receive the next frame. And in this sense, digital cameras have already caught up with, for example, video cameras and continue to "merge" with them. Digital cameras have RAM: "soldered", as in old computers, or more progressive, external, on removable flash cards. Their integral accessory is a hard drive or a standard ATA device, and sometimes even a floppy drive, or a SCSI drive. The digital camera allows you to create your own programs for shooting and image processing. A "sound card", a microphone or a speaker makes it possible to record voice comments during shooting, which can later be heard during playback. The camera is not deprived of communication devices either: an external interface via fast USB, FireWire or SCSI buses, along with serial (RS-232) and parallel ports (for direct printing on printers) that have already become commonplace and outdated. Some modern cameras also have an infrared port or even a network interface. Not to mention the various joystick buttons, including those with easily recognizable names. There are many ways to view footage captured with a digital camera. First of all, you can immediately see them on the built-in liquid crystal display. You can send information to the TV screen by connecting to it via a standard cable. The same cable will connect the camera to a VCR, which will copy frames from its film without any problems, like ordinary television. Postcard-sized pictures can be printed on a dedicated printer. Finally, the computer does not stand aside either: images can be submitted to its port through a separate block. In general, a truly digital camera is a real multimedia computer, in which both a serious programmer and an amateur can try their hand. Until recently, the digital camera lagged behind the conventional camera only in terms of image resolution. There were objective reasons for that. The fact is that the volumes of photo files in their original, "raw" form are very large. Depending on the quality of the photosensitive layer, they must contain up to 35 million pixels (the smallest distinguishable image elements by any means) to be equal to the frame of a 18 mm film. Moreover, each pixel carries more than one bit of information. This is true only for a black and white image, without any halftones. And for a full-fledged transmission of grayscale, at least 8 bits are required, and even the same amount for each of the three primary colors. That's where 24, 32 or even 36 bits per pixel come from. Therefore, digitized frames with good resolution and color reproduction were "too heavy" from the very beginning even for fairly powerful computers, and not only for digital camera processors. But a number of recent achievements allow solving the problem. First, the speed of the mentioned processors has sharply increased. Second, high-density CCDs have fallen in price, as have memory devices, both for computers and digital cameras. As a result, high-resolution equipment becomes available to the masses of amateurs. Finally, thirdly, faster and more efficient image compression algorithms are being developed at a fast pace. So it is possible to reduce the huge volumes of graphic files several times and, accordingly, increase the number of frames in the camera's memory and speed up their rewriting to the computer. Well, there you can already expand the image files again to the full, original resolution. And yet, as it turned out, you can change the design of the CCD matrix itself. In Japan, a so-called super-CCO matrix has recently been developed. In contrast to the already familiar rectangular arrangement of photodiodes that form a single image element - a pixel, photodiodes in a super-CCD matrix have an octagonal shape and are located at an angle of forty-five degrees relative to each other. Thanks to this "honeycomb" structure, the photodiodes are closer to each other, that is, the relative area occupied by them has increased. As a result, the effective surface area from which light is taken has increased significantly. Ultimately, the sensitivity of such a matrix increases, that is, the signal level per unit area of the CCD matrix increases and, as a result, spurious noise decreases. According to the manufacturer, the effective surface is increased by 1,6 times, color reproduction and signal-to-noise ratio are improved, the dynamic range is expanded, energy consumption is reduced, and image sensitivity and resolution are increased. A photograph taken from such a 1,3-megapixel super-CCD sensor is almost identical in quality to that obtained from a traditional "square" sensor with a resolution of 2,1 megapixels. A digital camera is still more expensive than conventional ones. However, in reality it is not so expensive, given its advantages. It saves time, and the cost of its maintenance, unlike film, can be reduced to almost zero. After all, the memory of a digital camera can be used repeatedly, the batteries can be recharged, and the pictures can not be displayed on paper, but stored only in electronic form. Author: Musskiy S.A.
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