Rohit Singh asked:


A single-Layer BD has storage capacity of 25GB, while a dual-la

Blu-ray Disc (also known as Blu-ray or BD) is an optical disc storage media format. It is mainly used in high-definition video and data storage. Blu-ray Disc has the same physical dimensions as a standard DVD or CD.

 

A single-Layer Blu-ray has storage capacity of 25GB, while a dual-layer BD can store up to 50GB of data. As the name suggests, a blue-violet laser is used to write data on a Blu-ray disk, unlike the traditional method wherein red laser employed to store data on DVDs.

 

A Blu-ray disk can hold 9-hour high definition video and standard-definition (SD) video that can run 23 hours, on a 50GB disk. The BD-ROM movies will require a rate of MBPS for data transfer, so the expected speed is 2x (72 Mbps). There is also a scope for having much higher speed because of the larger numerical aperture (NA) adopted by the BD. It implies that a Blu-ray disk will need less recording power and lower disk rotation speed vis-à-vis conventional DVDs and HD DVDs. The sole limiting factor for blu-ray is the capacity of the hardware.

 

The storage capacity of Blu-ray disk (BDs) is five times that of conventional DVDs. BDs supports NPEG-2, MPEG-4 AVC and SMPTE VC-1 formats (codecs).

 

Blu-ray Disc uses a “blue” (technically violet) laser operating at a wavelength of 405 nm to read and write data. Conventional DVDs and CDs use red and near infrared lasers at 650 nm and 780 nm respectively.

 

The blue-violet laser’s shorter wavelength makes it possible to store more information on a 12 cm CD/DVD sized disc. The minimum “spot size” on which a laser can be focused is limited by diffraction, and depends on the wavelength of the light and the numerical aperture of the lens used to focus it. By decreasing the wavelength, increasing the numerical aperture from 0.60 to 0.85 and making the cover layer thinner to avoid unwanted optical effects, the laser beam can be focused to a smaller spot. This allows more information to be stored in the same area. For Blu-ray Disc, the spot size is 580 nm In addition to the optical improvements; Blu-ray Discs feature improvements in data encoding that further increase the capacity.

 

 

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Chayawee Thawornsatian asked:


Blu-ray Disc: New storage technology

The currently DVD and CD technologies used red laser to stored and reading data that it have 650 nanometer and 780 nanometer wavelength of DVD and CD. But the new technology to store and reading data to DVD and CD developed by Sony and Phillips have only 405 nanometer wavelength. Blu-ray, blue laser technology in storing and reading data is an optical storage format created to store large amounts of high definition video and sound. The color of the laser is a hue of blue-violet and has a shorter wavelength than the red lasers.

The benefits of Blu-ray technology compare with the normal red lasers used today besides the shorter wavelength is capable of storing a much larger amount of data using the same space and also can be read to give a clearer picture with more color and vividness.

The reason to support the above benefits is because the blue laser required a smaller spot size. The wavelength of blue-violet laser uses a 0.85nm pickup aperture. Because of the extreme density of these optical discs, it can fit a large data onto the disc such as 23.3GB of data onto single-layer Blu-ray disc and 46.6GB onto dual-layer Blu-ray disc.

Deplorable condition of Blu-ray technology is it is easy to contaminate by only scratch because of so close together of data. And the really disadvantages of these technology is the Blu-ray disc are so expensive (about the $1,000).

Blu-ray is a new release technology of the electronics market compete with HD DVD’s and looking to make for the PlayStation of Sony. Sony will include the basic Blu-ray disc player with the PlayStation3 as a standard. But the Blu-ray disc is more expensive than the standard DVD counterparts. Therefore the both of two media type must to fight to be a winner. However, the Blu-ray disc need to develop about the way to prevent the scratching of the disc or difficult to scratch for easiness competition. But another reason will make Blu-ray disc have a trouble is it has been developed in part with Sony and Sony also has digital rights management (DRM) that will make the user more difficult to place shift and time shift their content. Now the people are waiting to see who is the winner between Blu-ray and HD.

Jim Williams asked:


We just bought a Blue ray HD DVD player for our HDTV. After we got it hooked up, which took a spell… I, for some reason or another just realized that I did not have any HD movies for me to see on it. Fortunate I already knew which one I sought to see firstly and that was Planet Earth.

So I got on the cyberspace and purchased it from an online outlet. The bad occurrence though is that I had to wait three days; nonetheless I did reserve myself around twenty dollars, so it was worth the wait. So it came with multiple disks with around three to four episodes of Planet Earth on each of the disks.

If you did not know already each episode of Planet Earth is one hour long. So once I put in Planet Earth to analyse on our HDTV I went to the listing of the premiere disk for the premier film. As you can ideate it was quite amazing how fine the picture looked.

All of the landscapes were rotund as can be in vividness and the animals looked as if they were graceful across the screen as they moved. I was impressed also on how well Planet Earth was filmed with a HDTV camera.

Some of the animals they picture in the movie looks as if they are right there close to them and the animals are not even being disturbed by them being around. It is really the most impressive movie of its type. One programme that really impressed me is the freshwater one.

In the kickoff of it, it shows Angel … the highest water descend in the world. Then it starts to break off from there and shows the rare animals that live in the freshwater environment. Another thing Planet Earth does is how well it shows the over view of the elevation.

Many shots are taken in high Earth altitudes while others are from space viewing the landscape and everything around it. The space shots are also one of my preferred things to look at.

Of course on our HDTV it looks as superior as it possibly can but it gives you a intuition of how bitty the World truly is but at the same minute when it talks about many of the environments it feels that the world is very gargantuan.

When you are watching Planet Earth you may get to an environment that they begin to speak about that just looks alien to you. Many of the things that are in the surroundings seem as if it was not proper and you can not even imagine about being in some of these places in real life.

One that truly shows what I am talking about is the caves instalment. Essentially what it shows you is the underground world of Earth. How things work under the surface and the uncanny little creatures that inhabit the caves.

It is truly something that will be hard for most people on the planet to conceive once they have seen any of the impressive animals that live on it. This infotainment is truly awesomel especially if viewed on a HDTV!