Frederick Wiseman has been making his fly-on-the-wall, narration-free documentaries for nearly half a century now, and his latest—a four-hour tour of the campus of the University of California at Berkeley—can be seen as a sort of counterpart to one of his earliest, “High School” (1969).

As in that film, much of “At Berkeley” consists of excerpts from classrooms of various kinds, including a course taught by Robert Reich also featured in his current film “Inequality for All” as well as science labs. These sequences are intercut with others showing discussions among administrators (including Chancellor Robert J. Birgenau) about how the school might respond to the drastic cuts in state funding that threaten the institution’s work, and occasional shots of students walking across the campus or lolling on the grass. At the close the film concentrates on a student demonstration that’s a much more sedate, practically-oriented affair than the ones for which the campus was famous in the turbulent sixties, and the calm, composed reaction of officials who treat it in a far more restrained fashion than was the case fifty years ago.

Like all of Wiseman’s documentaries, this one doesn’t push any particular agenda, other than to give the view a real feel for the way the institution on which he turns his lens operates. Some, perhaps most, audiences will find “At Berkeley” entirely too long, too slow, and insufficiently explanatory. But the patient viewer will come away from it understanding the breadth and importance of what such an academic enterprise does, the encouragement to grow and express themselves that it affords to youngsters still in process of intellectual formation, and the difficulties confronting those who struggle to maintain its excellence at a time of shrinking budgets and public criticism. For them it will be a work of uncommon depth and the sort of quiet conviction that sneaks up on you rather than hitting you over the head with its message.

The result is another Wiseman mega-documentary that may be challenging in terms of length but provides ample reward.