A secret history: "Beyond the Visible: Hilma af Klint"

Beyond the Visible is a documentary about discovery; it's the Searching for Sugar Man or Finding Vivian Maier of abstract expressionism. Director Halina Dyrschka's subject is Hilma af Klint, a Swedish painter of noble birth who was active from the 1890s onwards, yet whose work has only really been exhibited internationally within the past decade. So where had this trailblazer been hiding? The reasons for af Klint's underexhibition are guessable, to some extent: the hidebound attitudes of her time (insisting, as they did, that a woman couldn't be a serious artist, and that genius was an exclusively male preserve), and a reluctance among later curators to admit that everything they thought they knew - chiefly, that abstract expressionism began with Kandinsky and co. at the start of the 20th century - was fundamentally wrong. (An early side-by-side comparison in Dyrschka's film makes clear af Klint was painting similar shapes and colours at the back end of the previous century.) Yet we also learn af Klint set down her brushes prematurely to care for an aging mother - something her male contemporaries wouldn't have had to consider - and insisted, on her death, that her canvasses be sealed away, a wish converted into a fait accompli when they passed into the care of a nephew who regarded this oeuvre as a woeful burden. So Dyrschka pulls on her white gloves and picks up the pallet knife, keen to pare back the glaze of historical and critical indifference af Klint's work accrued over the past century, and thereby expose her subject's vibrant talent to a new, hopefully appreciative audience.

In this, Beyond the Visible proves highly successful. It has a rather uncertain opening - falling into the abstract before anybody broaches the expressionism - but once it gets into the biographical pith, the film is revealed as scholarly in the best sense. Instead of leaning on talking heads who might have reduced this story to the matter of an earcatching Radio 4 play, Dyrschka returns us time and again to the paintings, sketchpads and notebooks that lay out af Klint's workings, show how she developed, and speak for themselves; this camera has been set to collecting evidence, proofs of an underobserved life. Do the canvasses merit such sustained cinematic scrutiny? Yes, and then some. Partly, it's just that these upturned rectangles are so vast: Dyrschka observes an actress playing af Klint from above in reconstructions of studio life that immediately suggest some highbrow version of scenes from Take Hart or Art Attack. Completed, the paintings have a strikingly Scandinavian facility with colour and light. Her best works radiate and glow; they could be early prototypes for those lightboxes now used in the treatment of Seasonal Affective Disorder. (How apt that the film should be creeping out as we prepare to put the clocks back.) And though they contain their share of internal mysteries and ambiguities to be puzzled out by the onlooker, they don't appear to be tangled up with art theory, presumably as their creator wasn't spending her offdays jawing about her work in the usual boys' clubs. One benefit of being shunned by the artistic mainstream is that it leaves the creative free to work at his or her own pace, to do precisely their own thing. af Klint could be open to the elements (spiritual, scientific, natural) where her contemporaries were caught up in conversation and competition with one another, travelling as a group.

The art historians Dyrschka has assembled here - a thoughtful, eloquent (and largely female) collective, more than making up for the blindness of their predecessors - take a long, hard look at the work and arrive at a persuasive theory: that af Klint may finally have been too self-effacing to attain the reputation and retrospectives of a Malevich or Mondrian. We hear of her insistence that the marked, vital energy in her canvasses came from without and flowed through her; the suggestion is that this art was somehow a work of channelling rather than the tortured creation for which af Klint's male contemporaries were so feted. (A key-seeming biographical fact: af Klint spent time working as a medium, which landed her with the reputation in art circles of a kook or a crank. Look again, and there is an extent to which her paintings resemble signs and wonders in need of third-party interpretation.) Rather than impose herself on the landscape she found herself in, then, the af Klint of Dyrschka's engaging study became one with it; and with its abundance of natural imagery, Beyond the Visible proposes a merger between this most organic of artists - a vegetarian who kept notebook-listings of mosses, trees and leaves - and the wider world. Pulled out of the archives and into the light of a new century, we can now see how af Klint's spirals resemble fronds, petals, DNA helixes, how her concentric circles mirror those carved into tree trunks, a secret history inviting renewed examination. Evidently, af Klint's talent blossomed out of sight - exiled to the wilderness, while the male business of dealmaking and reputation management carried on in the city - but just because no-one was looking, it doesn't mean there wasn't a considerable beauty to behold.

Beyond the Visible: Hilma af Klint opens in selected cinemas from tomorrow.