Digital Single-Lens Reflex Camera

Cameras are devices that record and preserve scenes viewed through their lenses. The origin of modern cameras dates back to the 4th century BCE with the invention of the Camera Obscura, an early type of optical device. The development of silver halide film cameras later allowed images to be recorded on film. Today, digital cameras serve the same purpose by capturing and storing images as digital information. The basic working principle of a digital camera involves lenses that focus light rays from an object into a coherent image. The aperture controls the amount of light entering the camera, while the shutter speed determines the duration of exposure. When light hits a sensor (usually a CCD or CMOS sensor), it generates an electric charge. This charge is then converted to a digital signal by an Analog-to-Digital Converter (ADC). Each photosite on the sensor corresponds to a pixel, storing a specific binary value based on the light it receives. A pixel is a point in the image that contains three basic color components (red, green and blue). The number of pixels per square inch determines the resolution and quality of the image. Although the construction and functionality of digital cameras may vary across different types, the core principle of capturing an image using focused light, exposure control, and digital conversion remains the same.