Blu-ray, HD DVD, and High Definition FAQ

20th January 2008

High definition is new television format with a much higher resolution than the standard formats such as PAL and NTSC. This higher resolution produces very detailed images, and allows sharper video on todays large screen TV formats. To view HDTV you will require a television which supports the new format, and a high definition digital broadcast source, or Blu-Ray/HD player.

720i and 1080p are examples of a notation used to represent the varying resolutions of high definition television equipment. TVs are made up of a varying numbers of lines of pixels, so the number represents the amount of lines on the display. Also TVs can have two different screen refresh formats, Interlaced (i) and Progressive (p). A Progressive scan is where every pixel on the screen is updated for every frame of the video. Interlaced scan is when every second line is drawn for one frame, and the remaining lines in the following frame.

Blu-ray and HD DVD are competing optical disc formats, aimed at replacing the currently popular DVD format. The benefit of both formats over DVD is that they hold a much higher capacity of data, which it turn allows for the storage of more high definition video than a traditional DVD could hold. To view either format you will need a supported player, and preferably a high definition display.

The competing formats have been developed by two separate factions, with Sony/Philips for Blu-ray and Toshiba for HD DVD. The two sets of companies have suffered from age old disputes over royalties for the past DVD format, forcing them to go their separate ways over the new High Definition discs. Having two distinct formats in the market has its good and bad points, as although it is making it much more competitive, many consumers are confused over which format to invest in.

With the initial release of HD players costs were high, running into the thousands, but just like most new technologies these prices come down over time. You can now get a player for a few hundred pounds, and with the competitive nature of Blu-ray and HD DVD, you should be able to find some good deals.

The recommended retail prices of new HD releases are about the same as current DVD prices (£25-ish), but some discounts can be found by hunting around the price comparison sites, and the discount retailers such as Play and Sendit.

Both formats capacity is mainly dictated by the amount of layers on a disk, and it's not completely clear what the limit on the number of layers will be. Blu Ray can hold 25gb per layer, while HD DVD can hold 15gb. Video storage capacity is very much determined by the quality and definition of the video, but Blu Ray will have a slight edge due to its extra data capacity.

It is expected that most Blu-Ray and HD DVD players will be backwards compatible with DVDs, allowing you to play your old films. You should be aware though that it is up to the hardware manufacturer to support this feature, so it's best to confirm this with your supplier before purchasing your player.

All versions of the Sony Playstation 3 support Blu-Ray, while the Microsoft Xbox 360 supports HD DVDs, but only with the purchase of an additional external HD DVD drive. The Nintendo Wii supports neither format.