HD stands for High Definition (HD) and is a digital video format and offers the promise of sharper, clearer pictures and sound than currently available using analogue video and television formats using the PAL / SECAM or NTSC system.
There are two standards of HD which are 720 and 1080. Each can be shown and recorded in two different ways, Interlaced (i) and Progressive (p). Each uses square pixels. This gives rise to the four commonly stated standards which are: 720i, 720p, 1080i, 1080p.
To understand better it is worth first looking at the common PAL system which is used currently in the majority of VHS, DVD, television and projection systems used in conference presentations.
PAL has only half the resolution of 720 HD and only a fifth of 1080 820 HD.
HD based video (720 or 1080) are a vast improvement on PAL systems with a significant improvement in the clarity of image, amount of detail visible and improved colour rendition.
Using HD based source material, cameras and presentation formats in the conference arena offers significant opportunities to increase the impact of presentations and the method of display.
We are all familiar with the standard conference set of a projection screen or two, mounted against a felt covered stage set lit from above and below with a couple of static logo boards attached.
This can now be changed into something altogether more dynamic and useful.
Prior to the advent of high brightness projectors large displays were often limited to the use of videowalls (visible joins and high cost) or low light environments (audience in the dark and presenters unable to maintain eye contact). HD enables the screens to be larger without loss of clarity, colours and detail in PowerPoint text, data, graphs and pictures more lifelike with resulting message transmission, reception and retention by your audience.
HD uses square pixels as a standard, so do the latest generation of DLP projectors and these are now available with native HD resolution, therefore your source and the resulting projected display are exactly as intended, without any degradation or scaling.
With PAL based systems the larger the screen the more the original source materials lack of inherent data becomes apparent.
From this it can be seen that the images are broken down into much smaller chunks with the use of HD this enables much larger screen sizes to be used without the picture looking blocky or having jagged edges to diagonal lines, pictures, numbers and fonts.
Examples include pin sharp PowerPoint text and graphics and excellent colour rendition; for AppleMac users Footnote is as the designer intended – no reduction in quality from PC to the large screen.
Camera shots of presenters enable clear bright and lifelike images.
Screens may make up the whole of the set backdrop with overlaid multiple live images reflecting the mood of the conference, and particular presentation elements.
Close up detail of artefacts are possible (e.g. components, medical…) with enhanced clarity previously achieved with great difficulty and at significant cost.
That all important "wow" factor has extra dimension and flexibility.
What you see as clear and evident on your PC screen remains so at screen sizes measured in metres.
David Gray is Technical Director at Status AV - a high end audiovisual company based in the UK. He has experience of a huge range of installations and event productions, including high definition and widescreen projection. |
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