Why are cdr burn rings lighter than dvdr burn rings?

[yoda313]

I have just started burning audio cds after going a long time without doing so.

I am using some memorex discs I still have. I have just noticed that the burn rings are much less defined on the dye side of the disc than on the back of dvdrs.

Usually on a dvdr (most are a shade of purple) the separation line between burnt and unburnt sections is pretty dramatic.

Is the lighter less apparent separation on cdrs because of the dye used?

Or is it because of the nature of the beast? Since cdr's hold only 700mbs at best (sans the 900+mb non spec discs) compared to 4.5gb or 8gb dvdr is that the difference?

Are we actually physically seeing the data density difference between the two physical formats? I never considered that until now.

I know that dvds hold more than cdrs because the pits that hold the 1s and 0s are tighter than a cdr. And the same is essentially true for bluray so far as I know.

I don't have a bluray burner so I don't know what a partially burnt bluray disc looks like between the burnt and unburnt sections but I'm gonna guess it will be similar to dvdrs. And certainly I assume it is more of a difference than cdrs.

OR is it a matter of brand? Do different cdr brands have different density in the dye producing a more sharp difference between the burnt and unburnt sections?

Is there a more technical term then burnt and unburnt?

[DB83]

Just my two cents on this.

Its a matter of light and shade. I looked at two different burnt CD-Rs. One was silvery(yes, it was a CD-R) and you could hardy see the division unless you turned the disk to reflect the light. The other had a green tint and the division was a lot clearer.

The DVD-R's I use have more colour and, again, it is easier to see the division.

[johns0]

The dye used when burned is what causes the color changes.

[yoda313]

@DB83 - ok. I think I see that. I am only using one brand for this example at the moment.

@johnsO - So it is only a matter of dye?

[johns0]

Ya,if you burn a cdr with dark blue dye you will see the burn lines.