(click on image for full view)The red laser used to read DVDs has a wavelength of 650nm. The costlier blue laser used to read Blu-ray discs has a wavelength of 405nm but thanks to better tracking, the track pitch on a Blu-ray disc is only 320nm compared to 740nm on a DVD. For this reason, a Blu-ray disc can hold about 5 times more data (25GB) than a DVD. A dual layer Blu-ray disc can hold 50GB of data (over 9 hours of HD video). The format has support for even more layers so for instance, Pioneer's 16 layer Blu-ray disc holds upto 400GB of data.
There are basically three ways to do Blu-ray. A dedicated player, a Sony PS3 console, or a computer with Blu-ray drive. If we reach price parity with the West in an year's time then the dedicated player (Sony BDP S350) we pay 20,000 Rupees for today might be available for more like 10,000 Rupees next year. The Sony PS3 console would retain most of its value because it is first and foremost a game console (and a mighty fine one at that). Similarly a PC or laptop would also retain its value because it is a primarily a computer. That said, a Blu-ray writer (Sony BWU-300S) actually costs more than a dedicated player. A Blu-Ray reader (Sony BC-5100S or Asus BC-1205PT) however, is priced around Rs 12,000. Here again, price parity with the West would cause these drives to cost half as much as they do now.
