- Factor - number that tells how many times exposure must be increased in order to compensate from loss of light.
- Fahrenheit scale - scale of temperature named after its German originator, G. D. Fahrenheit. On this scale, the freezing point of water is 32° F, and the boiling point of water is 212° F. F=(C*(9/5))+32
- False attachment - part of one object seen behind another so that lines, shapes or tones seem to join up. A composition device used in various ways to produce images in which foreground and background objects appear to occupy the same plane.
- Farraday shutter - high-speed shutter using a pair of crossed polarizers, between which is a glass block within a coil. When a voltage passes through the coil, the plane of polarization changes, allowing light to pass through the second polarizer.
- Ferric chloride - bleaching solution used on negative materials.
- Ferrotype process - method of creating direct positive images with dark enameled metal plates as a base. Also known as the tin-type process.
- Film characteristic curve - describes a graphical relationship between the logarithm of the exposure value (horizontal axis) and density (vertical axis) of film. Each brand of film exhibits a different characteristic curve.
- Finality development - prolonged development, reducing silver halides affected by light to silver until no further image density improvement occurs.
- Flashing - briefly and evenly exposing photographic materials to white light.Often used to lower contrast of printing paper, when the flashing exposure is made in addition to the regular exposure.
- Fluorescent whites - brilliant highlights produced by applying a fluorescent agent to a printing paper base. The print can also be treated after washing with a fluorescent whitener or dye solution.
- f numbers -e numbers on the lens barrel indicating the size of the aperture relative to the focal length of the lens. f numbers are calculated by dividing the focal length of the lens by the effective diameter of the aperture.
- Fogging (Fog) - produces an overall veil of density on a negative or print, which does not form part of the image. It can be achieved by chemicals or exposing the sensitive material to light.
- Frilling - wrinkling and separation of the emulsion along the edges of its support material.
- Futurism - art movement started in Italy c. 1910, characterized by an aggressive rejection of tradition, and the representation of the dynamic movement of machinery.