> It's interesting that the author talks about posterization at 8-bit, but
> demonstrates it with a 50-level gradation (i.e. less-than-6-bit). Why
> would someone do this?
It demonstrates the problem using two small on-screen images.
If 6 bits is not enough there, then clearly 8 bits is not going to cut
it on anything you print.
One operation always causes me to hit the 8 bit limit. If I have an
unequally lit scene and want to correct for it, I multiple a gradient
onto it. But doing so lowers my dynamic range, i.e., I might be left
with only 7 bits of precision. I wouldn't have to care if I had instead
gone from 14 bits to 13 bits.