As I understand it (from various episodes of dl.tv), when producing Blu-Ray / HD DVD disks studios have returned to the original celluloid and scanned at the HD resolutions. Like still-camera film, celluloid has a much higher theoretical resolution than any image produced by a digital sensor. Apparently, according to Robert Heron on dl.tv, some of the rescans have been rather poorly effectedwhat is especially evident is that there is serious wear at the beginning of reels (so the beginning of most films, sometimes perhaps half-way through as well) and this is shown as poor quality on the HD disk.
Someone'll no doubt correct me if I'm wrong on this.
