"The Single-lens-reflex Camera"

Four things that are important:

Electromagnetic Spectrum-The range of all possible frequencies.
Lens-Assembly of lenses used in conjunction.
Photographic Film-Is a sheet of plastic coated with an emulsion containing light-sensitive silver halide.
Film Frames-Is one of the many single photographic images in a motion picture.

Other important words:

Aperture-
Is a hole or an opening through which light travels.More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane.

Shutter-
Is a device that allows light to pass for a determine period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene.

Exposure-
Is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph.

Depth of Field-
Is the portion of a scene that appears acceptably sharp in the image. Although a lens can precisely focus at only one distance, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the unsharpness is imperceptible under normal viewing conditions.

F-stop-
an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; in simpler terms, the f-number is the focal length divided by the "effective" aperture diameter. It is a dimensionless number that is a quantitative measure of lens speed, an important concept in photography.

Focal length-
The pinhole camera model describes the mathematical relationship between the coordinates of a 3D point and its projection onto the image plane of an ideal pinhole camera, where the camera aperture is described as a point and no lenses are used to focus light.