Photo Glossary

F-number

A number that indicates the size of the lens opening on an adjustable camera. The common f-numbers are f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, and f/22. The larger the f-number, the smaller the lens opening.

Factor

A number that tells how many times exposure must be increased in order to compensate from loss of light.

Fast film

A film with high sensitivity to light, needing less light for proper exposure. Recommended for action and low-light light photography.

Fast lens

A lens with a maximum wide aperture.

Ferric chloride

It is bleaching solution used on negative materials.

Fiber based paper

It is photographic paper without a resin coating.

File format

A program or data file type such as JPEG, PSD, TIFF, PDF, PICT, EPS.

Fill light

A source of illumination that lightens shadows.

Film

Photosensitive material used in a camera to record an image.

Filter

A colored glass or plastic disk used over the lens to emphasize, eliminate, or change the color or density of the entire scene or certain areas within a scene.

Filter adapter ring

Used to accommodate larger diameter filters on a smaller diameter lens.

Filter factor

It is a number by which an unfiltered exposure reading must be multiplied to give the same effective exposure through the filter. This compensates for the absorption of light by the filter.

Finder

Abbreviation for viewfinder.

Fisheye lens

It is extreme wide angle lens. Angle of view can approach 180 degrees depth of field is practically infinite.

Fixed focal length

A camera with unchangeable focal length (a non-removable, non-zoom lens).

Fixed focus

A lens camera system that has been focused in a fixed position by the manufacturer.

Flare

The reflected light from lens elements, sun, metal. Appears as non-uniform haze or bright spots on the film or digital frame This usually happens when a bright light directly enters the lens.

Flash

Artificial light source.

Flash card

Memory device capable of holding data after the system is turned off.

Flash compensation

A control on a speedlight and a method to reduce or augment the flash output from a flash to lighten or darken the flash effect.

Flash sync (Flash synchronization)

The shutter speed that corresponds to the proper timing of the flash.

Flat

Used to describe a negative or print with very low contrast.

Flat lighting

Lighting that produces very little contrast or modeling on the subject and a minimum of shadows.

Flood lamp

Photo lamps used for wider areas.

Floodlight

It is artificial light source with a dish shaped reflector lamp producing evenly spread illumination over the subject.

Focal length

The distance between the back lens element and the focal plane.

Focal plane

The area of the camera where the lens focuses on the film or digital sensor.

Focal point

The point on the optical axis where light rays form a sharp image of a subject.

Focus

It is a position in which rays of light from a lens converge to form a sharp image.

Focus range

The range within which a camera is able to focus on the selected picture subject.

Focusing magnifier

The device to magnify the optical image and aid visual focusing.

Focusing scale

It is a scale of distances marked on a lens focusing ring.

Focusing screen

It is ground glass screen fixed to the camera at the image-forming plane, enabling the image to be viewed and focused.

Foreground

The area between the camera and the main subject.

Format

A size of negative paper or camera viewing area.