August 17th, 2009Digital camera
Camera
A camera is a device that records images, either as a still photograph or as moving images known as videos or movies. The term comes from the camera obscura (Latin for “dark chamber”), an early mechanism of projecting images where an entire room functioned as a real-time imaging system; the modern camera evolved from the camera obscura.
Cameras may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A camera generally consists of an enclosed hollow with an opening (aperture) at one end for light to enter, and a recording or viewing surface for capturing the light at the other end. A majority of cameras have a lens positioned in front of the camera’s opening to gather the incoming light and focus all or part of the image on the recording surface. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.
A typical still camera takes one photo each time the user presses the shutter button. A typical movie camera continuously takes 24 film frames per second as long as the user holds down the shutter button.
Digital camera
A digital camera (or digicam for short) is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor.
Front and back of a Canon PowerShot A95.
Many compact digital still cameras can record sound and moving video as well as still photographs. In the Western market, digital cameras outsell their 35 mm film counterparts.[1]
Digital cameras can do things film cameras cannot: displaying images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, recording video with sound, and deleting images to free storage space. Some can crop pictures and perform other elementary image editing. Fundamentally they operate in the same manner as film cameras, typically using a lens with a variable diaphragm to focus light onto an image pickup device. The combination of the diaphragm and a shutter mechanism is used to admit the correct amount of light to the imager, just as with film; the only difference is that the image pickup device is electronic rather than chemical.
Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialised digital cameras.
December 3rd, 2009 at 7:24 am
Technology has evolved in a manner that make s human life easy a lot. Digital cameras are revolution for the photography. With the increase and development of technology we are getting better and better devices everytime.