David Kehr has written this very interesting article for the New York Times about Blu-ray DVDs and older movies. In particular, Kehr argues that the clarity of digital technology is actually a problem for older films because it exaggerates their flaws.
For bringing the latest Hollywood blockbusters into homes, Blu-ray is without parallel. But it is less friendly to older films, foreign films and films made with antiquated technologies (like 16 millimeter and analog video).
For Blu-ray to look its best it requires picture and sound images of the finest, most pristine quality. That’s not difficult to come by in a contemporary release like “Transformers: Revenge of the Fallen” (the best-selling Blu-ray of 2009), but is somewhat more problematic for a film made in Germany in 1926. Blu-ray exaggerates the faults in older material: the dust specks and scratches caused by decades of wear and tear, the softness of detail or harshness of contrast caused by duplication from sources several generations removed from the film that actually passed through the camera.