Franco gives one of his most subtle performances yet as a recovering-alcoholic father, and the three young newcomers’ performances are honest and affecting, capturing what it feels like to be adrift and on the verge of adolescence.

Yosemite is a contemplative drama, low-key perhaps to a fault. But Demeestere shows acute sensitivity in her understanding of boys and their growing awareness of the world, with its real and imagined menaces.

Resolutely unshowy, sometimes almost too lower-case in its observations, Yosemite pays off in an authenticity that pervades both individual scene rhythms and performances.

Like Gia Coppola's Palo Alto (2013), a lyric and biting evocation of contemporary well-to-do teendom, Gabrielle Demeestere's Yosemite mines Franco's fiction for its most vital quality: his unsentimental depiction of youthful insecurity, this time among fifth-graders.

Ms. Demeestere’s direction winds up frustratingly splitting the difference between thoughtfully detached and just plain vague.