Rope was NOT edited from end-to-end to appear to be one continuous shot--despite what a substantial number of film “historians” have written. Following the title sequence shot, there is a cut to a near-180-degree vantage point. From then on, the story is enacted in ten camera takes of about 8 1/2 minutes each. There are cuts disguised as continuations of action (by having the camera pass a dark space at the end of one roll and the beginning of the next) at the ROLL changes, but there are CONVENTIONAL CUTS at the REEL changes.
The movie cameras at the time could only accommodate 1000 feet of film (11 minutes, 6 seconds), and the projectors could accommodate reels of no more than 2000 feet. Thus, each projection reel (if filled out to a practical length) needed to have at minimum two shots, after which theaters would switch from one projector to another. In that time (1948) before automated switching from one projector to another, the switch-over was done manually; machine operators could not be expected to be so exact as to avoid missing some of the last split-seconds at the end of a reel (which is why on older movies, there is usually facial reactions or physical action at the switch-over point, so as to prevent dialogue being cut short), so having a conventional cut (a change in p.o.v.) at the reel change was mandatory. The “disguised” cuts occur mid-reel only (this being where two rolls were put together).
A look at the film “Rope” reveals that in addition to the cut that occurs immediately after the opening credits, there are four conventional cuts. Typically, the cut is made to a close-up of a face while the person who was talking at the end of the previous take continues talking at the beginning of the new take.