Introduction to Photography: Light, History, and Technology

Cameras capture light, the core of photography. They use lenses to focus light rays onto a surface inside the camera, where the image is recorded.

Before modern cameras, there was the camera obscura. A dark room with a small hole, it projected outside scenes onto opposite walls, upside-down.

Film cameras use chemical reactions on film to capture images. Digital cameras convert light into electrical signals using sensors, storing images as data files.

ISO measures sensor sensitivity to light. Higher ISO allows shooting in low light but can introduce graininess, known as digital noise.

Aperture controls the lens opening size, affecting light entry and depth of field. A wider aperture creates a shallow depth, blurring the background.

The oldest surviving photograph was taken in 1826 and required an 8-hour exposure time.