New York documentary filmmaker Doug Block, whose 2005 debut film, "51 Birch Street" offered an MRI scan of his parents' unsatisfactory marriage, turns his lens on his daughter and wife for his followup. Block intently filmed his daughter, Lucy, from early childhood, when she was thrilled to see herself from angles no mirror could capture, through her departure for college in California, when her feelings for Dad's ever-present camera are much less enthusiastic. The end product exists in a kind of ethical and aesthetic twilight zone. It's impossible to draw the line between actual "caught" moments and vignettes arranged to be filmed. It's like viewing home movies edited by Pirandello.

Block is a mostly offscreen presence in the film, asking Lucy again and again how she feels, what she plans to do when she grows up, and other clueless, superficial, fatherly questions. His narration is a poignant meditation on the loss of intimacy between them, pensively wondering how it all happened. It's astounding that he couldn't look at his obsessive record of her childhood and see the simple truth. As interviews with his aged father dramatize, Block is carrying a wheelbarrow full of separation anxiety from his own childhood.

Block's focus on his beautiful, bright daughter makes a bit player of his wife, Marjorie Silver, a centered, no-nonsense law professor. Silver accepts Lucy's first love affair with a handsome French student, a situation that raises Block's hackles. She candidly diagnoses her husband's Peter Pan approach to parenting, acting the part of Lucy's pal rather than doing the work of a responsible authority figure.

"The Kids Grow Up" is a warts-and-all self portrait. Block treats his daughter's departure not as a normal, bittersweet rite of passage but as an occasion for pathos, and he observes that self-dramatizing reaction candidly. Here he may be doing a service to other clingy baby boomers. As Block notes, Lucy and her classmates "had the misfortune to be born at the infancy of the commercially available camcorder." At a pre-prom party organized by her classmates' parents, the teenagers pose like Kardashians while their folks snap pictures and shoot video as if they were paparazzi.

The images that linger most powerfully are halves of a complex emotional equation. First, there is a shot of a lengthy conversation between Block and Lucy, around age 7. Somehow the sound track was mislaid, and in a voiceover Block mourns the loss of that recording, like many other heart-to-heart talks they shared. The other half of the equation is repeated shots of Lucy asking her father to turn off the camera, to stop filming her life and to begin experiencing it. Only by letting it go could he have actively taken part in her life. Oh, well. At least he got a movie out of it.

Colin Covert 612-673-7186