Blu-ray Clarification Needed ASAP!



Hi all – I’m new and I have a question. In an article written and posted on this site regarding the differences between Blu-ray and HD-DVD, they say one of the differences is the structure of the discs. The Blu-ray disc is composed of a 1.1 mm layer and .1 mm protective coating… the HD-DVD is composed of a .6 mm layer and .6 mm protective coating. The article says the reason the Blu-ray can hold more is because the laser only needs to go through .1 mm of space versus the HD-DVD of .6mm, therefore it can record more which means increased capacity… is that accurate??? – I have been looking everywhere and can’t seem to find someone (Blu-ray Disc Association or familiar) to confirm if that is true or not – HELP!!! Please clarify if you know!!


If you look at your post you will see that two parts are in blue. Click on them and they will take you to articles on CD freaks that should give you more information and may even clarify it for you.


physics is clarifying this

NA (Numerical Aperture): higher NA (because of the lower distance from lens to recording layer) = smaller spot size (diameter of the laserbeam) compared to HD-DVD

Because of this you can focus the laser with much higher precision and this allows to reduce the track pitch (distance between the centers of two adjacent tracks on a disc) and the pit length. = Higher data density = more capacity


dont scratch that blu-ray or u will be buying a new disc to replace it

sorry i like a lil protection :wink: