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Showing posts with label
Summertime in Kiel - photos made by Sabine.
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Showing posts with label
Summertime in Kiel - photos made by Sabine.
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Many early such cameras could only capture grayscale images. To take a color picture, it required three separate scans done with a rotating colored filter. These are called multi-shot backs. Some other camera backs use CCD arrays similar to typical cameras. These are called single-shot backs.
Scanning and multi-shot camera backs are usually used only in studios to take pictures of still objects. Most earlier digital camera backs used linear array sensors which could take seconds or even minutes for a complete high-resolution scan. The linear array sensor acts like its counterpart in a flatbed image scanner by moving vertically to digitize the image.
Most digital cameras are built to operate as a self-contained unit. This is especially so at the lower-end, for these cameras usually include zoom lens and flashes that cannot be changed. However, at the highest-end, some digital cameras are nothing but a sophisticated light-sensing unit. Experienced photographers attach these digital "camera backs" to their professional medium format SLR cameras, such as a Mamiya.
Storage for digital cameras have increased in size and technology with the time. From magnetic tape( Steven Sasson's 1975 prototype) to floppy disc to flash memory.
Digital photography was used in astronomy long before its use by the general public and had almost completely displaced photographic plates by the early 1980s. Not only are CCDs more sensitive to light than plates, but they have a much more uniform and predictable response. The CCDs used in astronomy are similar to those used by the general public, but are generally monochrome and cooled with liquid nitrogen so as to reduce the noise caused by heat. Many astronomical instruments have arrays of many CCDs, sometimes totaling almost a billion pixels. Nowadays amateur astronomers also commonly use digital cameras, including the use of webcams for speckle imaging or "video astronomy".
However, digital cameras require batteries that need to be recharged or replaced frequently, and this means that a photographer needs access to electrical outlets. Digital cameras also tend to be much more sensitive to moisture and extreme cold. For this reason, photographers who work in remote areas may favour film SLR cameras, though many higher-end DSLRs are now equipped with weather-resistant bodies. Medium- and large-format film cameras are also still preferred by publications insisting on the very highest detail and resolution.
Other commercial photographers, and many amateurs, have enthusiastically embraced digital photography because they believe that its flexibility and lower long-term costs outweigh its initial price disadvantages. Almost all of the cost of digital photography is capital cost, meaning that the cost is for the equipment needed to store and copy the images, and once purchased requires virtually no further expense outlay. Film photography requires continuous expenditure of funds for supplies and developing, although the equipment itself does not outdate so quickly and has a longer service life. Some commercial photographers have also begun moving to digital technology because of the tremendous editing capabilities now offered on computers. The photographer is able to color-balance and manipulate the image in ways that traditional darkroom techniques cannot offer, although film users can utilize the same technology with a film scanner. With fully color-balanced systems from the camera to the monitor to the printer, the photographer can now print what is actually seen on the screen.
Some commercial photographers and some amateurs interested in artistic photography, have been resistant to using digital rather than film cameras because they believe that the image quality available from a digital camera is still inferior to that available from a film camera, and the quality of images taken on medium format film was thought to be impossible to match with a digital camera. Some have expressed a concern that changing computer technology may make digital photographs inaccessible in the future. A related concern in a specialized application is the use of digital photographs in court proceedings, with the added difficulty of demonstrating an image's authenticity. Some high-end film can also still be projected for viewing at a much higher optical resolution than even the best digital projectors.
Digital photography has also been adopted by many amateur snapshot photographers, who take advantage of the convenience of the form when sending images by email, placing them on the World Wide Web, or displaying them in digital picture frames. Digital cameras have also been integrated into many cell phones, although, because of the small, poor quality lenses and sensors in most of these phones, the quality of these pictures makes them unsuitable for making even moderate size prints.
With the acceptable image quality and the other advantages of digital photography (particularly the time pressures of vital importance to daily newspapers) the majority of professional news photographers have begun capturing their images with digital cameras.
Some digital cameras can show these blown highlights in the image review, allowing the photographer to re-shoot the picture with a modified exposure. Others compensate for the total contrast of a scene by selectively exposing darker pixels longer. A third technique is used by Fujifilm in its Fine Pix S3 pro digital SLR. The image sensor contains additional photodiodes of lower sensitivity than the main ones; these retain detail in parts of the image too bright for the main sensor.
Practical imaging systems, digital and film, have a limited "dynamic range": the range of luminosity which can be reproduced accurately. Highlights of the subject which are too bright will be rendered as white, with no detail; shadows which are too dark will be rendered as black. The loss of detail is not abrupt with film, or in dark shadows with digital sensors: some detail is retained as brightness moves out of the dynamic range. "Highlight burn-out" of digital sensors, however, can be abrupt, and highlight detail may be lost. And as the sensor elements for different colors saturate in turn, there can be gross hue or saturation shift in burnt-out highlights.
The quality of a digital image is the sum of various factors, many of which are similar to film cameras. Pixel count (typically listed in megapixels, millions of pixels) is only one of the major factors, though it is the most heavily marketed. Pixel count metrics were created by the marketing organizations of digital camera manufacturers because consumers can use it to easily compare camera capabilities. It is not, however, the major factor in evaluating a digital camera. The processing system inside the camera that turns the raw data into a color-balanced and pleasing photograph is the most critical, which is why some 4+ megapixel cameras perform better than higher-end cameras.
Digital photography is one of several forms of digital imaging. Digital images are also created by non-photographic equipment such as computer tomography scanners and radio telescopes. Digital images can also be made by scanning conventional photographic images.
Digital photography is a form of photography that uses digital technology to make images of subjects. Until the advent of such technology, photography used photographic film to create images which could be made visible by photographic processing. By contrast,.digital photographs can be displayed, printed, stored, manipulated, transmitted, and archived using digital and computer techniques, without chemical processing.
Scanning and multi-shot camera backs are usually used only in studios to take pictures of still objects. Most earlier digital camera backs used linear array sensors which could take seconds or even minutes for a complete high-resolution scan. The linear array sensor acts like its counterpart in a flatbed image scanner by moving vertically to digitize the image.
However, digital cameras require batteries that need to be recharged or replaced frequently, and this means that a photographer needs access to electrical outlets. Digital cameras also tend to be much more sensitive to moisture and extreme cold. For this reason, photographers who work in remote areas may favour film SLR cameras, though many higher-end DSLRs are now equipped with weather-resistant bodies. Medium- and large-format film cameras are also still preferred by publications insisting on the very highest detail and resolution.
Some digital cameras can show these blown highlights in the image review, allowing the photographer to re-shoot the picture with a modified exposure. Others compensate for the total contrast of a scene by selectively exposing darker pixels longer. A third technique is used by Fujifilm in its Fine Pix S3 pro digital SLR. The image sensor contains additional photodiodes of lower sensitivity than the main ones; these retain detail in parts of the image too bright for the main sensor.
Digital photography is a form of photography that uses digital technology to make images of subjects. Until the advent of such technology, photography used photographic film to create images which could be made visible by photographic processing. By contrast,.digital photographs can be displayed, printed, stored, manipulated, transmitted, and archived using digital and computer techniques, without chemical processing.
