Digital cameras are quite similar to traditional cameras in their operation. They both have a lens to focus the image, a shutter to allow light inside the camera, and an aperture to control the amount of light which enters the camera.

The differences between digital and traditional photography occur after the light enters the camera. A traditional camera captures the images on film, while a digital camera captures the image on an image sensor.

Image sensors are electronic devices made up of an array of electrodes (or photosites) which measure light intensity. The most common type of image sensor for digital cameras is the CCD (Charge-Coupled Device) although others such as CMOS and Foveon are sometimes used.

The number of photosites in the image sensor gives the digital camera its megapixel (millions of pixels) rating. Each photosite corresponds to a pixel in the final image, so a camera which is rated at six megapixels, for example, has an image sensor which is 3008 pixels wide by 2000 pixels high.

When light hits the image sensor it is converted into electrical signals which are amplified and fed to an analog-to-digital (A/D) converter. The A/D converter changes the electrical signal into binary numbers which are processed by a computer housed in the camera body. Once the numbers have been processed the resulting image is stored on a memory card.

Photosites can only measure intensity of light — not colour. In order to produce a colour image, each photosite must be covered with a coloured filter which can be red, blue, or green. These are the three primary colours which can be combined to produce any other colour including white.

The coloured filters are arranged in a grid so that there are twice as many green filters as there are red or blue. This is because the human eye is twice as sensitive to green light. Filters are arranged in a pattern called the Bayer pattern - one row of red, green, red, green (etc.), and the next row of blue, green, blue, green (etc).

Since each photosite can only be covered with one coloured filter, computer processing is necessary to produce a full coloured image. This is done by analyzing each individual pixel and its immediate neighbors and producing a composite colour from these calculations. For example, if a bright red pixel is surrounded by bright green and bright blue pixels, the bright red pixel must actually be white, because white is the combination of red, blue, and green. This process is called demosaicing.

After demosaicing the image is adjusted according to the settings on your camera. Most cameras have settings for brightness, contrast, and colour saturation. After these adjustments are made some cameras may also apply a sharpening algorithm to make the image clearer.

The final step before saving the image on the memory card is to compress it. Most cameras use JPEG as a compression format. This reduces the size of the file by eliminating excess data. This data cannot be recovered, so JPEG is called a ‘lossy’ format.

Many cameras have the ability to save uncompressed images as TIFF files or raw data. Raw data is the original photosite data even before demosaicing. It can be transferred to a computer for processing with special software that will perform all of the processing functions of the camera but with much greater control.

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The conventional camera depended entirely on chemicals and mechanical processes - nothing else was required to make them work. Following along on the footsteps of major technological breakthroughs in consumer electronics, the new digital camera is part of this fundamental shift in technology.

The digital camera has two things: a built-in computer, and electronic recorded images. They have not entirely replaced the conventional camera, though, as film represents the highest quality of pictures.

The early digital cameras were used to store images on memory devices within the camera, then transferring the images to the computer with the help of cables. Today, most digital camera makers provide reusable and removable storage devices, such as SmartMedia cards, CompactFlash, cards and Memory Sticks. Some other removable storage devices include the floppy disks, hard disks, or micro-drives, writeable CDs and DVDs. This has considerably enhanced the volume of visual data that can be stored.

A digital camera uses light converted into electrical charges, instead of film, to take pictures. It focuses this light through a lens or a series of lenses onto a sensor, which records the image electronically. The sensor used the most is employed by a CCD (charge coupled device) while others use a CMOS (complementary metal oxide semiconductor).

If a CCD is used to transport the charge, its sensors create a high-quality, low-noise image, while the CMOS are more susceptible to noise while traditionally using less power. The CCDs consume as much as 100 times more power than that of a CMOS yet have been mass-produced for a longer time. They have a higher number of higher quality pixels yet both play the same role - they turn light into electricity.

What every photographer is looking for is clarity and high detail, with very little blurriness or a grainy look. This has to do with the resolution of the camera, which refers to the amount of detail the camera can capture. Hewlett Packard estimates that a 35mm film is about 20 million pixels, considered a very high-resolution picture - 1216 x 912, or 2 million total pixels, is a photo lab quality for the 4 x 5 picture.

To break it down even more, a 1 megapixel digital camera will produce images that are good for e-mailing or posting on the Web because their resolution is low. The images taken from a 2-megapixel camera are suitable for 4×5 inch prints while those taken from a 4-megapixel camera can produce 16×20 inch prints.

The digital cameras use four kinds of lenses. These are: fixed-focus, fixed-zoom lenses; optical-zoom lenses with automatic focus; digital-zoom lenses, and replaceable lens systems. The fixed focus and fixed zoom lenses are used in inexpensive cameras while the optical zoom lenses have both wide and telephoto options. The aperture and shutter speed are used to control the amount of light that reaches the sensor.

The aperture setting, or the size of the opening in the camera, is automatic in most digital cameras but a few allow manual adjustment. This is because certain professionals or amateurs want more control over the final image. The shutter speed is the time amount that passes through the aperture. This can be set electronically, which is different than using film in the conventional 35mm cameras. The digital camera has a digital shutter, rather than a mechanical shutter.

Overall, the digital camera and the traditional film camera have the same principals. The both have a viewfinder for aiming the camera, the lens for focusing, the ability to store several images and remove them later on, with a compact format for everything’s storage.

Two different systems yet slightly the same - the conventional camera captured images with light-sensitive film to store them after chemical development, while the digital camera used memory storage and advanced image sensor technology, capturing images to store them in digital format that is instantly available instead of having to wait. Yet the digital camera is more environmentally friendly, keeping up with the issues of the world while photographing these issues at the moment they occur.

Bookmark to:

The conventional camera depended entirely on chemicals and mechanical processes - nothing else was required to make them work. Following along on the footsteps of major technological breakthroughs in consumer electronics, the new digital camera is part of this fundamental shift in technology.

The digital camera has two things: a built-in computer, and electronic recorded images. They have not entirely replaced the conventional camera, though, as film represents the highest quality of pictures.

The early digital cameras were used to store images on memory devices within the camera, then transferring the images to the computer with the help of cables. Today, most digital camera makers provide reusable and removable storage devices, such as SmartMedia cards, CompactFlash, cards and Memory Sticks. Some other removable storage devices include the floppy disks, hard disks, or micro-drives, writeable CDs and DVDs. This has considerably enhanced the volume of visual data that can be stored.

A digital camera uses light converted into electrical charges, instead of film, to take pictures. It focuses this light through a lens or a series of lenses onto a sensor, which records the image electronically. The sensor used the most is employed by a CCD (charge coupled device) while others use a CMOS (complementary metal oxide semiconductor).

If a CCD is used to transport the charge, its sensors create a high-quality, low-noise image, while the CMOS are more susceptible to noise while traditionally using less power. The CCDs consume as much as 100 times more power than that of a CMOS yet have been mass-produced for a longer time. They have a higher number of higher quality pixels yet both play the same role - they turn light into electricity.

What every photographer is looking for is clarity and high detail, with very little blurriness or a grainy look. This has to do with the resolution of the camera, which refers to the amount of detail the camera can capture. Hewlett Packard estimates that a 35mm film is about 20 million pixels, considered a very high-resolution picture - 1216 x 912, or 2 million total pixels, is a photo lab quality for the 4 x 5 picture.

To break it down even more, a 1 megapixel digital camera will produce images that are good for e-mailing or posting on the Web because their resolution is low. The images taken from a 2-megapixel camera are suitable for 4×5 inch prints while those taken from a 4-megapixel camera can produce 16×20 inch prints.

The digital cameras use four kinds of lenses. These are: fixed-focus, fixed-zoom lenses; optical-zoom lenses with automatic focus; digital-zoom lenses, and replaceable lens systems. The fixed focus and fixed zoom lenses are used in inexpensive cameras while the optical zoom lenses have both wide and telephoto options. The aperture and shutter speed are used to control the amount of light that reaches the sensor.

The aperture setting, or the size of the opening in the camera, is automatic in most digital cameras but a few allow manual adjustment. This is because certain professionals or amateurs want more control over the final image. The shutter speed is the time amount that passes through the aperture. This can be set electronically, which is different than using film in the conventional 35mm cameras. The digital camera has a digital shutter, rather than a mechanical shutter.

Overall, the digital camera and the traditional film camera have the same principals. The both have a viewfinder for aiming the camera, the lens for focusing, the ability to store several images and remove them later on, with a compact format for everything’s storage.

Two different systems yet slightly the same - the conventional camera captured images with light-sensitive film to store them after chemical development, while the digital camera used memory storage and advanced image sensor technology, capturing images to store them in digital format that is instantly available instead of having to wait. Yet the digital camera is more environmentally friendly, keeping up with the issues of the world while photographing these issues at the moment they occur.

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