Glossary » F

The length of time a printed document will resist fading due to the actions of ultra-violet light and ozone attack. Usually assumes the document is stored out of direct sunlight and may assume it’s held behind glass.

PAL video is made up of two fields that contain alternate lines which create a single frame when shown rapidly.

The sequence in which each alternate field of a video signal is shown.

A system or software utility designed to stop unauthorised access to a private network and can also be used by a company to control what resources outside the network can be accessed by employees.

IEEE1394a, its official name is, but it’s also known as iLink thanks to Sony branding. This is an interface similar to USB, although it’s not as widely used on the PC as it is on Macintosh computers. It’s most commonly used with a DV camcorder to transfer digital video to your PC for editing. The speed of Firewire is 400Mbits/sec (around 50Mbyte/sec) although a new faster 800Mbite/sec version (IEEE1394b) is now available. The data transfer rate of Firewire is a sustained transfer rate which means that you get full speed all the time. Other peripherals available with a Firewire interface include external hard drives, external optical drives, scanners and web cameras. The main advantage of Firewire over USB 2.0 is that the bandwidth is not shared between devices. Firewire can also provide more power to an external device than USB.

A product of phosphor persistence and how quickly the image on a monitor is refreshed. If the refresh rate is too low (below approximately 72Hz), the human eye will detect the drop in phosphor brightness between each screen refresh, giving rise to a perceivable shimmering to the image. This is known to cause headaches and eyestrain.

While describing the distance at which a lens comes into focus, focal length most commonly now refers to the field of coverage of a lens, with longer focal lengths having smaller fields of view than shorter, wider ones. Note most digital camera lenses are described by an equivalent range on a 35mm system for familiarity.

The ratio between focal length and the aperture of the lens, also known as the “f” number. The focal ratio of a lens is usually described with the aperture at its most open setting; if it’s a zoom lens, the focal ratio will be quoted at both the wide and telephoto ends

Generally this is defined as a point at which rays/beams of radiation converge to form a sharp image, usually after being refracted, reflected, deflected, and/or concentrated. For example: a. Focus can describe the ability of the cathode ray tube’s electron guns to accurately target phosphor dots on the back of the CRT screen in order to from a sharper picture. b. The ability of a lens/mirror to refract/reflect photons of light bouncing off the original image, so that these converge at the focal plane (i.e. inside a camera at which the C-MOS/CCD sensor or film is positioned).

In fogging, pixels are blended with a fixed colour taking on more of that colour as their distance increases. This gives the impression that objects are fading into a foggy distance. Fog is often used to cut down on the amount of geometry and rendering a scene requires.

The amount of space that a device’s physical dimensions occupy.

1) Frames Per Second. The amount of times a screen is redrawn in a single second. 2) First Person Shooter. The term given to games where you take on a first person perspective view, while dispatching enemies with various weapons - Half-Life, Doom and Halo are prime examples.

Like in video or film, a frame is a completed scene that’s ready to be displayed on screen, or in our case ready be sent by our graphics card to our monitor. The speed at which our graphics card is able to send completed frames to our monitor is known as the frame rate and is measured in frames per second or “FPS”

(Full Scene Anti-Aliasing). Trying to create a sloping edge with square pixels is like trying to create a sloping edge with building blocks, there’s always a step effect that ruins its appearance. Anti-aliasing is a method for adjusting the colour of these offending pixels so they blend better with the background and so become less noticeable.

Flatter Squarer Tube or Flat Square Technology. Describes the physical geometry of the viewing surface where a reduction in the curvature of the glass in the vertical plane helps minimise unwanted reflections and improves the appearance of straight lines on a CRT.

File Transfer Protocol - Commonly used for transferring files across an IP network.

A term from commercial printing, describing the ability to print ink right to the edge of a sheet of paper, rather than having a border round its edge. Also called borderless printing.