The film teaches itself to you.

Roger Ebert uses Riefenstahl's Triumph of the Will to plug the benefits of shot-by-shot analysis:

I began in about 1970, on the advice of John West, a Chicago film exhibitor, teacher and historian. "You know how coaches use a stop-action 16mm projector to go through game films?" he asked. "Do the same thing with a feature movie. You don't stop after every frame, of course, but you stop at anything interesting, and discuss it, and you can back up and look at it a frame at a time."

This I did, to begin with, during U of C classes. The rules were simple: Anyone in the audience shouted out "Stop!" and we did, and discussed why they wanted us to stop. Beginning with Hitchcock, who remains the most fruitful director for such analysis, I worked my way over the years through the work of Welles, Bunuel, Bergman, Herzog, Truffaut and many others. I found that with a large group, there would always be one member with the expertise to settle the question at hand: A Hungarian speaker, for example, or a psychiatrist, or a specialist on Japanese medieval history. The Colorado groups often numbered 1,000 students and locals, and over the years we formed a community.

Of course the introduction of the laserdisc, and later the DVD, made this process infinitely easier.

Amen. Allelujah!