In days of old, a special occasion was just incomplete without a photograph, that too with the typical poses and a fight to be a part of those few snaps. You don't experience such moments today. The use of a digital camera is no longer limited to a special occasion. The moment you see something interesting, you can just capture it with a click, and in no time the image is before your eyes. These consumer electronic products have undergone remarkable changes due to application of new technology, no longer restricting photography to professionals.
Digital cameras convert analog information to digital information, represented by ones and zeros or bits, a language that its built-in computer understands. This camera takes the image in an electronic format which is converted into the binary format. Each image is a long string of such 1's and 0's, and the smallest unit of an image is known as a pixel.
Light is focused by a series of lenses on a semiconductor device. This device records the light electronically and an image of the captured scene is created. This electronic information is then converted into digital data. An image sensor is used to convert light into electrical charges. This sensor is of two types: charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS). CCD sensors create high-quality images as compared to those created by CMOS sensors. However, CMOS sensors consume less power as compared to CCDs. Though there are many such differences between CCD and CMOS, both of them perform the same function of turning light into electricity.
Exposure and Focus
A digital camera controls the amount of light reaching the sensor with the aperture and shutter speed components. The size of the opening in the camera is known as aperture, which can be automatic or manual. Manual adjustment gives the user more control over the final output. The duration of time for which light can pass through the aperture is referred to as the shutter speed. The task of capturing the required amount of light to take a good image is performed together by these two components.
The lenses of the camera control the way in which the light is focused on the sensor. Though the lenses in digital cameras are very similar to those in conventional cameras, focal length is the main difference between the two. Focal length is nothing but the distance between the lens and the surface of the sensor. This length determines the zoom. Increasing the focal length, magnifies the image, while decreasing the focal length shrinks the image. A zoom lens is one in which the focal length can be adjusted. Digital cameras have optical zoom, digital zoom or both. Some cameras have a macro focusing feature, which helps in taking extreme close ups. Optical zoom lenses modify the focal length of the lens instead of just magnifying the information that hits the sensor. Digital zoom forms a full-size image by interpolating the pixels from the center of the image sensor. This may lead to an output of grainy or blurry images, but that depends on the resolution of the image.
Resolution is the amount of detail, assessed in pixels, that a camera can capture. The amount of detail a camera can capture depends upon the pixels of the camera. More the pixels it has, the more details it can capture. Also, larger pictures will be clear and not blurry. The resolutions range from the minimum of 256x256 or 65,000 pixels to 4064x2704 or 11.1 megapixels.
Focus on Colors
Filtering is used by most sensors to look at the light in three primary colors, red, green and blue. Once all the three colors are recorded by the camera, a full spectrum is created by combining them. The colors can be recorded in different ways. A quality digital camera uses three sensors. Each one of these has a different filter to view light in the primary colors. A beam splitter is used to direct the light to the sensors. The beam splitter divides light into three different sensors equally, giving each sensor an identical look of the image. Then comes the role of the filters, due to which each sensor responds to only one of the primary colors. This method enables the camera to record each of the three primary colors at each pixel location.
Most digital cameras have an LCD screen, which enables you to view your picture right away. This is one of the main advantages, as you get an immediate view of what you have captured. Obviously, viewing the image on your camera is not all, you may load the picture onto your computer, email it, or print it. Previously, digital cameras used to have fixed storage inside the camera and the images were transferred by connecting the camera to a computer via a cable; however, most of today's cameras use removable storage, like memory sticks. The images are usually stored in TIFF, which is an uncompressed format, or JPEG, which is a compressed format; some high-end cameras can even save images in a raw format.
Though today's point and shoot cameras have made photography ridiculously easy, there is a lot happening behind the scenes.