The design of photographic lenses for use in still or cine cameras is intended to produce a lens that yields the most acceptable rendition of the subject being photographed within a range of constraints that include cost, weight and materials. For many other optical devices such as telescopes, microscopes and theodolites where the visual image is observed but often not recorded the design can often be significantly simpler than is the case in a camera where every image is captured on film or image sensor and can be subject to detailed scrutiny at a later stage. Photographic lenses also include those used in enlargers and projectors.
Elements of an inexpensive 28mm lens
Photographic lens cut for demonstration
Diagram of Petzval's 1841 portrait lens - crown glass shaded pink, flint glass shaded blue
A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of the camera dates back to the 19th century and has since evolved with advancements in technology, leading to a vast array of types and models in the 21st century.
Leica Camera (1950s)
Hasselblad 500 C/M with Zeiss lens
Different apertures of a lens
The distance range in which objects appear clear and sharp, called depth of field, can be adjusted by many cameras. This allows a photographer to control which objects appear in focus, and which do not.