Lucasfilm technical director Mike Blanchard says, "Almost all of the resolution that’s lost is through the printing process. It’s really funny about technology and the film business right now. People get caught up in these numbers games that are flat-out ridiculous. They say, ‘Film is 4k,’ but it’s not 4k. It’s 4k on the camera negative, but no one has ever seen a camera negative projected. Countless studies have shown that what is shown in U.S. theaters [via the interpositive/internegative photochemical printing process] is between 700 and 800 lines of resolution when you get to the release print. We get that easily.
http://mixonline.com/sound4picture/film_tv/audio_star_wars_episode_2/