Well, I think that HD transfer advances like2K or 4K scanning it's a key reason in first place, despite I suspect some restoration use resolution that it's more marketing than really need, for example:
I don´t believe Gone Withn The Wind camera negatives have real benefits comparing the 4K restoration with the 8K restoration they did last time.
So why 8K ??? For marketing ? SOme technicians said a 6K would get more dynamic range due some details of tone depend of the grain precise shape.
But about fix deffects, I must agree that's a constant evolutions, and there are still a lot of deffects that are not well fixed even with actual last generation digital tools.
There is still no tool or filter to fix bromide drag.
Some spatial flicker, even in some films from 70's, are not very well fixed, despite be reduced in some degree.
Some very large scratches can leave artefacts when appear in a complex detail pattern.
But some softwares just fix a region of image, and also file, record, the non fixed area, so they can get back latter and try another fix for the same area. And a 4K scanning in digital restoration could save a non restored file, for a future new digital fix with improoved tools.
I think Warner had or should had a version of the 2K digital restoration (made by Lowry) without the grain reduction or contrast enhancment for shadow details.
Nick_M wrote:One reason we keep getting new versions is that previous restorations are, surprise, surprise, simply not good enough. A while back I read that Singin' in the Rain was saved as 1080i (!). It's sure dismaying, though, to see the studios spend so much wasted effort. In Universal's announcement of their new restorations, I was shocked to see them again brag about fixing the same damaged shot of To Kill a Mockingbird that they bragged about fixing in the Nov. '01 American Cinematographer. Should've been fixed properly the first time. Disney's been using what looks like the same transfer of Snow White for twenty years now, so it can be done.
Keep thinking...