0203 012 5566

Local Call Rate 0845 652 5566

(24 hours)

Plasma v LCD v LED

At first glance, Plasma and LCD and LED displays look the same. Both are thin and stylish. They have totally flat screens and both offer excellent picture quality. However there are some important factors that can determine which display is the right choice for your requirements.

How they work

Plasma screens are made of two sheets of glass, between which, xenon, neon and helium gases fill thousands of tiny chambers. Behind each chamber are a series of red, blue and green phosphors. When electricity hits the plasma chambers, they emit invisible UV light, which then hits one of the coloured phosphors. This creates a visible image on the screen.

Plasmas are usually heavier and in larger housings, and produce excellent picture quality which allows them to handle fast moving images very well. So for fast moving action, some sports for example ,Plasma can be a better choice. One negative point with Plasmas is they can suffer with "screen burn" where a single motionless image will be "burned" into the display if left for too long.

An LCD display is made up of an LCD panel containing millions of tiny pixels, behind this panel sits a fluorescent white backlight.

Each pixel consists of a shutter and a coloured filter, of which the shutter is used to control how much of the white backlight can pass through it and uses the coloured filter to determine what colour is displayed. The millions of pixels combined make up the image that you see. Due to the nature and response speed of LCD's, the picture quality is not so good on video and fast motion images, although new techologies from the major manufacturers are aiming to remove any issues. Some succeed quite well.

The newly realeased LED screens are technically not made using LED for the image pixels, but the LED term refers to the replacement of the fluorescent white backlight with LED backlighting, of which there are two methods. Dynamic RGB LEDs, which are positioned directly behind the LCD panel (providing a better contrast ration but slightly less definition), or white Edge-LEDs positioned around the rim of the screen, which uses a diffusion panel to spread the light evenly behind the screen.

Size and weight

LCD screen sizes generally range from 19" to 58" although larger sizes are becoming more widely available, they are more expensive than the equivalent plasmas, due to higher manufacturing costs. At the time of writing, the largest LCD available is Sharp's 108". LCDs are slightly thinner and lighter than plasmas.

Plasma screens range from the most common size of 42" right up to an impressive 103" with larger sizes constantly being developed. At the time of writing, Panasonics' 152" is the largest plasma in the World, although not yet commercially available.

Newer plasmas are lighter than their predecessors, however they are usually around 10% heavier than LCDs due to the glass panels. The newer LED LCD Panels are usually lighter, and much thinner than the other types.

Picture Quality

LCDs are renowned for producing brighter pictures as a consequence of the technology used. Bright pictures expose more detail and make colours look instantly engaging but images can appear superficial.

As plasma pixels can be controlled to emit no light at all they produce deeper black levels, which define contrast. Even when an LCD pixel is switched off, light emitted from the backlight escapes leaving blacks a dark shade of grey. Plasmas also produce better greyscale subtleties that reveal more detail in dark picture areas.

The bright nature of LCDs make primary colours appear instantly vibrant. Plasmas produce natural, more accurate colours with a wider range of subtleties across the spectrum.

Motion rendering was considered to be better in plasmas as faster pixel response times cope with fast-paced action better.

Older LCDs suffered from blurred edges and streaming trails, however most new LCDs feature anti-blur technology. LCDs with a 120Hz refresh rate are fairly common, with high-end LCDs offering a 240Hz refresh rate.

A faster refresh rate enables video to look smoother. Plasmas do not need to use this type of processing.

High Definition

High definition refers to a video that has a substantially higher resolution and better sound quality than the traditional standard definition system.

The two standard resolutions of High definition are 1280x720 and 1920x1080. They are often referred to as 720p, 1080i and 1080p. The number stands for the number of horizontal scan lines, while the letters refer to either i for interlaced or p for progressive, with progressive being the better of the two.

Today, Plasmas and LCDs are typically advertised as being either "HD Ready" or "Full HD", and these terms reflect the native resolution of the plasma/LCDs panel.

"HD Ready" typically means the native resolution of the panel is 1366x768, meaning it is capable of showing full 720p but has to compress higher resolutions to fit.

"Full HD" refers to having a native panel resolution of 1920x1080 and is capable of showing full, uncompressed video at 1080p.

In the domestic market, High definition is transmitted using the HDMI interface. This type of connection supports any kind of video format and up to 8 channels of uncompressed audio. It has a maximum cable length of approximately 10 metres.

In the professional market, High definition is transmitted most commonly using HD-SDI, although HD-SDI only supports up to 1080i. When 1080p transmission is required, Dual-link HD-SDI can be used. HD-SDI is known to be reliable at lengths of up to 80 metres.

Most professional plasma/LCD displays have interchangeable input boards, this provides the ability to install whatever connection is required.