Final Cut of Blade Runner was spent figuring out if Deckard was a replicant or not ("Do I have any coverage of that?") and half the time he spent taking out the wires and cables that were suddenly visible in the new hi-definition formats.
Film is a different medium than digital, and has grain, 24 images per second, moves through the projector and each image is distinct, different, contrary - the inherent blur tends to soften sharp distinctions between shots. Just ask ILM.
Blu-ray imagery is sharper and doesn't move - it's an algorithm that reveals anything the original film could pick up and holds it still for our eye. In hi-def 4 times as sharp for our edification. And in its crystal clarity lies the rub.
The mechanics of film is forgiving and tricks the eye. When lit properly rear-and front-projection screens look real in their soft-focus background. Matted shots blend more smoothly with the hard surface of the foregrounds. Cables that held the helicars up disappeared in the smoke, but Scott had to have them digitally removed for the blu-ray.
Tom Savini's make-up effects, intended to go by in single-digit frame-flashes in the old Friday The 13th movies convince even less than they did then.
Movie theatres used to be large dark rooms and the light, this big at its source, would be expanded and diffused through the hundreds of feet it travelled to the movie screen, by 1000% or more. Effects were engineered and designed to work as well as they needed to. They didn't need to stand up to intense scrutiny.
You could get away with the flying horse in The Adventures of Baron Munchausen. There's a reason why it hasn't been upgraded to blu-ray. It would look too shabby. That film's been denigrated enough.
Blu-rays reveal the flaws of the source. And at a certain point you get diminishing returns. The beginning 15 minutes of Kubrick's 2001: A Space Oddysey appearing to be shot on the veldt of prehistoric Africa was actually shot on a soundstage with large front-projection screens behind the rocks and the men-in-suits. On a large screen it's entirely convincing, as is the small cut-ins of people moving in the windows of the model spaceships on the moon.
Yet, finally, on the beautiful blu-ray I recently acquired (what could go wrong?) there are clear panels marring the prehistoric sky. The resolution of the blu-ray reveals the folds in the fabric that is hanging behind the sets; the clear "sheetiness" of it, hell, I swear, even the remnants of old western landscapes that seem to have been painted over or obscured that would have been, at most, a blurry trace when filmed and projected.
Deep and nuanced and not quite visible, like the past it depicts.
The tolerances built into the old systems have been decalibrated and the nuances are now hammer blows. The film, so much of its time (1968) is built as best it could be then, with paper cut-outs and fake backgrounds.
A blu-ray upgrade has made me strangely sad.