QUOTE(terbang @ Nov 12 2008, 08:07 PM)
i have read some of the reply here said that, some shop is change the original dual-layer laser of the ps3 to the single layer laser..that y the price is cheap than or they can give many of free gift..
is that true??

Interesting... I would want to know more about this.
Sourced from Wikipedia again:
"Laser and optics
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.[42] In addition to the optical improvements, Blu-ray Discs feature improvements in data encoding that further increase the capacity. (See Compact Disc for information on optical discs' physical structure.)"
Any experts here know anything about single/dual layer lasers?
Added on November 12, 2008, 8:51 pmThis is from
http://www.blu-ray.com/faq Storage capacity 25GB (single-layer)
50GB (dual-layer)
Laser wavelength 405nm (blue laser)
Numerical aperture (NA) 0.85
Disc diameter 120mm
Disc thickness 1.2mm
Protection layer 0.1mm
Hard coating Yes
Track pitch 0.32µm
Data transfer rate (data) 36.0Mbps (1x)
Data transfer rate (video/audio) 54.0Mbps (1.5x)
Video resolution (max) 1920×1080 (1080p)
Video bit rate (max) 40.0Mbps
Video codecs MPEG-2
MPEG-4 AVC
SMPTE VC-1
Audio codecs Linear PCM
Dolby Digital
Dolby Digital Plus
Dolby TrueHD
DTS Digital Surround
DTS-HD
Interactivity BD-J
If there's this thing called "single-layer" / "dual-layer" laser, then what will be the wavelength for each respective lasers?
This post has been edited by geekster129: Nov 12 2008, 08:54 PM