Glossary » P

The basic building blocks of all 3D models, polygons are three sided (triangle), four (Quadrilateral) or more (simple) geometric tiles, which can be strung together to form simple or complex shapes depending on the number used.

A page or screen orientation that is taller than it is wide.

The period required by a video recorder before the picture becomes stable and usable.

Primitives are the basic components such as points, lines or polygons, from which a 3D model is created.

The number of dots a printer can produce within a given distance. Normally expressed as dots per inch. The higher the resolution, the more detail a printer should be able to reproduce. Other factors play a part in the perceived detail level of colour images, too.

This is a method of distorting what would otherwise be a flat surface by applying a programmed set of deformations to its vertices. Effects are usually dynamic such as rippling water but they can also be static.

This is a version of procedural texturing carried out using a graphics card’s pixel shader to define the colour of each pixel.

Unlike a conventional texture map, which is essentially a 2D bitmap image, a procedural texture is created by your graphics hardware from nothing based on a mathematical, usually fractal “recipe”. This is useful for texturing complex shapes, which can be difficult to texture map in a conventional way and is also a more efficient way of creating 3D textures.

Exposure mode which automatically adjusts the aperture and shutter, but normally offers greater adjustments than plain Auto modes.

Instead of interlaced fields of video, progressive scan records and plays back entire frames.

Phase Alternate Line. The TV system used in Europe based on 50 fields per second and 625 lines.

A measurement of the density of a grade of paper, in grams per square metre (gsm). Normally related to the thickness of a sheet. Typical weights are 80gsm or 90gsm for office paper used in photocopiers or printers, up to 230-250gsm for photo papers and thin card.

A method of connecting computer peripherals, often a printer to a PC. Parallel connections are being phased out in new equipment, in favour of USB or Firewire links.

A particle system builds an image component using a collection of points or primitives rather than by stringing polygons together. These points can be programmed with unique attributes that dictate how they behave as a group and particle systems have been used to create everything from smoke and fire to flocking birds and fountains.

A type of LCD consisting of transparent conductors running to the edge of the display in a grid of rows and columns. Connected at each grid intersection is a liquid crystal pixel (or RGB sub-pixel in a colour display). When a current is applied to these intersections the pixels are pulsed on. However, because the pixels are pulsed on, rather than being held on for each frame refresh (like an active matrix LCD), passive matrix displays have to use liquid crystals that maintain their ‘twist state’ until the next time the screen is refreshed. This leads to lower response times and smearing of moving images.

Private Branch Exchange - A privately owned telephone exchange.

Plug used to connect to external lighting or certain flash guns, typically used in professional studio environments. Always verify a PC Sync port will work with specific lighting though, as high voltages could permanently damage a camera.

Peripheral Component Interconnect - a standard connector for add-on cards on a motherboard. This tends to be a white slot, but may differ depending on the make of the motherboard. The PCI slot operates at 33MHz and is 32bit wide.

PCI Express is the latest standard for expansion cards and will come in several different versions. The first types to appear are x16 and x1 lanes, with x4 and x8 versions to follow. The x16 lane is reserved for graphics, while the x1 lane together with the x4 and x8 slots are multi purpose. PCI Express offers much improved bandwidth compared to PCI as the x1 lane offers 500MB/sec of bandwidth compared to 133MB/sec for PCI. The bandwidth is shared between all attached devices on both PCI Express and PCI. The connectors are not backwards compatible, as an x1 slot is about ¼ of the length of a PCI slot. The x16 slot is similar in size to an AGP slot, but as with the x1 slot it is not backwards compatible.

Intel’s brand name for its performance consumer processors, of which the Pentium 4 is the current version.

This term can be applied to both CRTs and LCDs. More commonly, it describes how long the phosphor coating in a CRT continues to emit light after the electron beam has been removed. A long persistence reduces flicker but may create motion smearing (like a radar reading). With LCDs it describes how long the LCD crystal can maintain its orientation after the current has been removed.

Refers to the application of a texture to a polygon specifically allowing for its location and perspective in 3D space. Without correction some textures can display visual deformities when used with some perspectives.

PFC – Power Factor Correction Modern power supplies are of the switching type and thus discharge some 50-100,000 times a second. This means that there will be all sorts of electromagnetic and radio frequency interference. This is not desirable as this can cause feedback into your electrical system and cause interference elsewhere in your home or office. The PFC is a type of filter that removes most or all of this interference. It also corrects any phase misalignment that may occur in the AC power. This is done to provide “clean” power to the components inside a computer. There are two types of PFC, active and passive. Passive PFC is never as efficient as active PFC but it is cheaper. This method tends to use a ferrite core inductor, while active PFC uses various transistors and integrated circuits. All home appliances sold within the EU that consume 70W or more, must have some type of PFC correction. PFC is measured as a percentage - the higher the number, the more efficient.

The chemical substance used to coat the inside surface of a CRT. Phosphor emits light when the electron beam excites it, and ultimately it is this light our retinas respond to. Different phosphors are used for each red, green and blue phosphor dot or line.

The triangular cluster of three phosphor dots, one each of red, green, and blue found in a shadow mask CRT. The holes in the shadow mask expose one phosphor triad to the electron beams. If all the dots in the triad are hit with the same intensity then the phosphor triad as a whole will emit white light. In practice 1.2 or more phosphor triads will constitute one pixel, depending on the dot-pitch and resolution of the monitor.

A technique of ejecting drops of ink from the head of an inkjet printer, by applying a small current to a piezo crystal and causing it to move. The movement creates a minute pumping action, sufficient to expel the ink. Pioneered by Epson.

A pipeline is the term used to describe a specific data path through a processor.

The ability to rotate a monitor’s display (typically an LCD) from a landscape position to a portrait one, and vice versa.

Contraction of the words “picture element,” a pixel is the smallest, discreetly addressable part of a monitor. In a CRT a pixel is composed of red, green and blue phosphor dots, whereas in an LCD a pixel is composed of fluorescent light from the backlight passing through red, green and blue filters.

A pixel shader handles small programs or instruction sets and applies them to each pixel received through the graphics pipeline.

A software extension such as an effects package that can be added to increase the capabilities of an editing platform like Premiere.

Power Over Ethernet - The technology to transmit power as well as data over traditional CAT5e cabling.

Personal Media Player - a portable device that plays music and video. Often referred to as MP3 players.