Blu-ray is a cutting-edge, high-definition optic disc that can store significantly more data than a appropriate Dvd. A single-layer Blu-ray disc can store almost 25 gigabytes of data: five times the estimate of a appropriate single-layer Dvd. Dual-layer Blu-ray discs can store twice the estimate as single-layer discs, and about eight times the estimate of a appropriate dual-layer Dvd.
A appropriate Dvd contains adequate space for a two-hour, non-high-definition movie, plus a few extra features. A Blu-ray disc allows adequate space for 13 hours of appropriate footage or two hours of high-definition video. In addition, Blu-ray discs allow you to skip abruptly everywhere on the disc; article one show while watching another; edit and reorder the footage on the disc; and access the web to download subtitles and other extras.
Blu-ray
All Dvd's and Cd's store data as a series of grooves on the recording exterior of the disc. The grooves are written in a spiral that winds from the center of the disc to the exterior edge. On one side, the grooves appear as pits; on the other, they stand out as bumps. To read the disc, a player shines a laser over the bumpy side of the disc. The bumps cause the laser to bounce back and register on a sensor.
Standard Cd and Dvd players use a red laser to read the data on a disc. Blu-ray compatible players use a blue laser. Blue light has a shorter wavelength than red light. This makes the laser itself more sensitive and capable of detecting much smaller grooves than a red laser can.
Because the blue laser can detect smaller grooves, the data on a Blu-ray disc can be written much smaller than on a appropriate disc. This is why a Blu-ray disc can include so much more data than a appropriate Cd or Dvd, even though the discs are the same size.
Blu-ray discs are constructed differently than appropriate discs. These differences in construction eliminate some of the found flaws in appropriate Dvd's. One of these flaws is birefringence. In a appropriate Dvd, the recorded data is set in the middle of two polycarbonate layers. The laser must shine straight through a layer of polycarbonate in order to reach the data.
Occasionally, the polycarbonate can split the laser into two beams instead of allowing it to penetrate, making the player unable to read the disc. The process of lining up the polycarbonate layers must be done with great precision to prevent birefringence. In addition, the laser beam can become distorted if the disc is not perfectly level inside the player, a problem called "disc tilt."
On a Blu-ray disc, the data is printed on top of the polycarbonate layer. With the data on top, the laser does not have to shine straight through polycarbonate in order to read it-and the problem of birefringence is eliminated. This simplifies the manufacturing process, and keeps the cost of Blu-ray discs down. In addition, the data's location brings it closer to the lens that reads the laser. This makes disc tilt much less of an issue.
Blu-ray market more data, reads more clearly, and provides interactive features you can't get on a appropriate Dvd. There aren't many drawbacks to Blu-ray, but there are a few.
Blu-ray discs need dissimilar tool to manufacture. Despite the ease of making these discs in comparison with appropriate Dvd's, manufacturers still have to spend in new machinery to make them. This may give a tiny edge to Blu-ray's major competitor: Hd-Dvd. Hd-Dvd is someone else type of high-definition Dvd that can be man-made using the same tool used for appropriate Dvd's. It market less information, but it's also less expensive.
Blu-ray discs aren't more high-priced than appropriate discs, but Blu-ray players tend to be significantly more high-priced than Hd-Dvd players. You can buy players that will play appropriate formats along with either Hd-Dvd or Blu-ray, but no player can read both Hd-Dvd and Blu-ray.
Both Hd-Dvd and Blu-ray have strong sustain in the market, but neither one has yet gained an edge over the other. Like format wars of past eras, many consumers are reluctant to spend in an high-priced new player when they don't know if the format they select will survive. However, Blu-ray is a strong contender, and it just might emerge victorious.
Blu-ray Technology - What It Is And How It Works
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