What's the difference between a normal blank CD and CD's given magazines,etc....
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K
krazyfrog
Guest
The green or golden colour of blank discs is mostly due to a layer of ScratchGuard applied to its surface to protect it from scratches. This layer is found only on blank media. The colour is there to differentiate it from non-ScratchGuard discs. Other discs don't have this layer. So they look silver.
gauravakaasid
Back to l33ching :)
AFAIK the cds given away by magazines are stamped, they are not written to. i guess that may be one of the reasons why they have a silvery surface.
blackpearl
The Devil
The greenish color is due to the organic dye used in blank CDs.
Blank CDs are different from the ones given by Digit, the silvery ones. A "real" CD (the silvery CD) contains pits and bumps which corresponds to 1s and 0s. When a laser beam hits a bump it gets scattered and when it hits a pit, it gets reflected back to the lens.
The blanks CDs on the other hand, does not contain pits and bump. Rather they posses a layer of organic dye on the surface which turns opaque when exposed to laser light of a certain wavelenght, just like the dye used in photographic films. The CD writer "burns" this organic dye, i.e. exposes them to a laser beam which turns specific areas opaque. When you read such a CD, the opaque areas does not reflect light and behaves like a "bump" while the unburnt areas reflect light which behaves like a "pit".
The discs given by Digit are the "true" optical discs in the sense they contain real pits and bumps and are called pressed discs. The blank CDs just try to emaluate these optical discs. A special method is used to make pressed discs and such discs usually lasts longer because the pits and bumps are permanently etched into the surface. But written CDs dosen't last long because over time the organic dye detoriates, and the data becomes corrupt. Just like old photgraphs get discoloured and smeared, because home written discs are just a "photographic print" of a real optical disc.
Blank CDs are different from the ones given by Digit, the silvery ones. A "real" CD (the silvery CD) contains pits and bumps which corresponds to 1s and 0s. When a laser beam hits a bump it gets scattered and when it hits a pit, it gets reflected back to the lens.
The blanks CDs on the other hand, does not contain pits and bump. Rather they posses a layer of organic dye on the surface which turns opaque when exposed to laser light of a certain wavelenght, just like the dye used in photographic films. The CD writer "burns" this organic dye, i.e. exposes them to a laser beam which turns specific areas opaque. When you read such a CD, the opaque areas does not reflect light and behaves like a "bump" while the unburnt areas reflect light which behaves like a "pit".
The discs given by Digit are the "true" optical discs in the sense they contain real pits and bumps and are called pressed discs. The blank CDs just try to emaluate these optical discs. A special method is used to make pressed discs and such discs usually lasts longer because the pits and bumps are permanently etched into the surface. But written CDs dosen't last long because over time the organic dye detoriates, and the data becomes corrupt. Just like old photgraphs get discoloured and smeared, because home written discs are just a "photographic print" of a real optical disc.
K
krazyfrog
Guest
^^ Thanks for the great info mate. Reps added to your account.
seriuslyblack
Broken In
blackpearl said:
whew! never knew this info. thanks man!!
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