On Sat, 2017-05-20 at 18:54 -0600, JD wrote:
Another blog I recall reading said it has to do with what the Medium
informs the drive the speeds it is capable of being written to.
Yes, they have a list of supported speeds (it'd be in some pre-amble
area to where you're going to burn to.
Burning discs is like photography. Enough exposure is needed to create
the image, and there's two variables: The strength of the light, and
the exposure time.
Burners have a finite number of power levels that they can emit at,
likewise with the number of available disc spinning speeds.
Discs have a list of speeds (in essence laser power *and* speed) that
they're rated to work at. Which don't usually offer single spin,
anymore, making them somewhat difficult to use in video DVD recorders
making live recordings (that want to burn in real-time, in one go,
rather than in a stop/start fashion). Even 2x speed is getting rare.
To burn a disc, you can only user the speed/power combinations that are
compatible with the burner and the disc.