“At Berkeley” screens at 1 p.m. Saturday at the UW-Cinematheque, 4070 Vilas Hall, 821 University Ave. Not rated, 4:04, three and a half stars out of four. FREE!

That running time in the above description is not a misprint. Legendary documentary filmmaker Frederick Wiseman’s “At Berkeley” clocks in at over four hours, which you’d think would make viewers eligible for some kind of college credit.

So why did I find “At Berkeley” more gripping and involving than Wiseman’s (shorter) previous couple of documentaries, “Crazy Horse” or “La Danse?” Wiseman’s style is to make films about institutions and systems, and sometimes I wonder if his fly on the wall of those systems isn’t discriminating enough on what it chooses to see. But here, looking at a year at the life on the UC-Berkeley, his camera captures the many moving parts of a world-class university. And, very subtly, shows us the ways they connect and conflict.

What’s the relation, say, between a fascinating lecture on poverty and inequality, and a scene of a university worker patiently using a leaf blower to clean debris off picnic tables? Or grad student researchers talking about their latest development, contrasted against a seemingly banal board meeting? The mundane enables the high-minded, it seems — somebody has to sign the checks and sweep the floors, often invisibly to the students, so that those engaging classroom discussions can take place.

On their own, many of the scenes are illuminating vignettes, such as former Labor Secretary Robert Reich dishing to his class about how dull faculty meetings are (“They are used to hearing themselves speak, and they are used to seeing others nod in response.”) But together, they form a wide-ranging tapestry for the modern university system, the struggle between its ideals and its realities.

And throughout “At Berkeley,” distant fiscal drumbeats can be heard in those board meetings, talk of receding state funding and the need to make priorities. General talk about necessities turns into specific proposals to raise student fees, hitting middle-income students hardest. Over the course of several hours, we watch as these issues push their way to the forefront of conversations inside and outside of classrooms, culminating in a massive student demonstration. But even then, what’s fascinating about “At Berkeley” isn’t the uprising but the institution, as it manages the unrest, controls it, waits for it to dissipate.

At any point, Wiseman could tip his hand, show sympathy to either the students or the administration. But at 84, he’s a master at just watching the system work and letting the audience form its own conclusions. “At Berkeley” is an epic watch, but you certainly come out of there feeling like you’ve learned a lot.