A documentary by Frederick Wiseman. Rating unavailable

National Gallery depicts its subject less as a collection of great images than a place of concentrated engagement. Imagery, of course, is the starting point for the London-based institution containing more than 2,300 classical paintings seen by over six million visitors a year.

The most deceptively undemanding guest here is documentary veteran Frederick Wiseman, now 84 and in his fifth decade of fly-on-the-wall filmmaking. As always, he appears to drift through his chosen staging area, skipping title cards, music, and voice-over explanation, thereby making his scene selection seem much more organic than it probably is. Of course, a three-hour doc about an art gallery is more likely to contain commentary on the editing process than, say, Wiseman’s recent four-hour campus tour At Berkeley or State Legislature, which was like Idaho getting its own C-Span.

In fact, most scenes in National Gallery, whether shot in open spaces, teaching auditoriums, workshops, or private meeting rooms, have something to say about perception itself, with curators, lighting technicians, restorers, and docents all building on—or sometimes thwarting—the artists’ original intentions. Tour guides, art experts, and TV presenters are all caught bringing detailed observations to works by Turner, Titian, and others, while life-drawing classes and various discussions (several involving departing director Nicholas Penny) happen in the recesses of the massive building on Trafalgar Square.

Viewers will differ as to which extended passages they find most interesting; one restoration specialist’s dissection of an X-rayed Rembrandt lasts about 12 minutes. Rubens’s Samson and Delilah gets two, highly contrasting analyses. And there’s even a class for elderly blind people, with specially embossed prints handed out for discussion.

Certainly, art lovers will enjoy the wealth of views aired here, with their senses sharpened, not just framed, by the experience.