A documentary by Errol Morris. Rated PG

Elsa Dorfman’s name is not on the lips of your average photography collector and that’s pretty much the point of the latest from veteran provocateur Errol Morris (The Fog of War).

Among other heavy-duty threads connecting Morris’s work, the untrustworthiness of memory may be the sturdiest. Here, retrospection is made tangible through the sharp-eyed portraits of Elsa Dorfman, a perpetually jolly Massachusetts photographer who recently turned 80. The filmmaker spends most of the doc’s swift 75 minutes in her cramped Cambridge studio, as she goes through past work on the eve of her retirement. It’s some archive! Moving to New York City in 1959, she took pictures as a way to hang around the scene at Grove Press, then a hotbed of poetry, political dissidence, and censorious upheaval.

Through Grove’s auspices, Dorfman—who calls herself “one lucky little Jewish girl”—captured timeless images of writers like W.H. Auden, Anaïs Nin, and especially Allen Ginsberg, with whom she forged a lifelong friendship. (Audiotape of his call just before dying is an emotional highlight of the mostly upbeat film.)

She was later able to shoot ’60s icons like Bob Dylan and Joni Mitchell. But Dorfman never caught on with magazine editors or with gallerists, and instead went back to Cambridge and set up a moderately rewarding portrait business. Although she never received any financial support from Polaroid, she ended up owning one of only five 20x24 cameras they made, and the large-format portraits it yielded became her bread and butter.

Normally shooting two final images on the expensive film, she kept the rejects—the “B-sides” of the title. She also ended up with a stash of that Polaroid product, but now that it’s almost gone, Dorfman herself ends up a scratchy B-side of the lapsed century. But that’s not fair, Morris seems to argue. She was a hitmaker from the start.