Camera
From The Glossary of Digital Photography
A device designed to capture images. In its most basic form, the camera has an aperture to allow light to enter a chamber, a shutter to control the period of time that the light enters, and some kind of mechanism to fix the image in a more permanent form. This mechanism can be film or a digital sensor. The aperture can be a simple pinhole or an adjustable diaphragm that can be changed in size to allow more or less light in. In front of the aperture there is usually also a lens, to provide more adjustment over image size and angle of view. The shutter can be a simple flap, a focal plane curtain, or a series of overlapping leaves. In each case, the shutter is designed to control the amount of time that light can enter the camera. In addition to these basic requirements, some sort of viewfinder is included so that the image can be composed. In the case of a digital camera, this viewfinder can be an optical viewfinder that either looks through the main camera lens, as in the case of an SLR, or through a smaller separate lens. Digital cameras often also have an electronic LCD screen. This LCD screen can be active and used to compose the image, or it can be used after the image is captured to view the resulting digital image. See also LCD; aperture; diaphragm; image sensor; lens; shutter
