BALZAC had some unusual ideas about photography, a new invention in his time. The Frenchman believed that all objects were “made up of a series of ghostly images superimposed in layers to infinity,” and that the camera captured one of those layers. Tacita Dean’s eerie new exhibition at the National Portrait Gallery, on until May 28th, in which flickering cinematic screens float in the middle of dark rooms, like layers caught in suspension, seems to encourage such spiritual notions as Balzac’s.

Ms Dean was nominated for the Turner Prize in 1998, and found success as part of the generation of so-called Young British Artists. But unlike her contemporaries Damian Hirst and Tracy Emin, Ms Dean is not quite a household name. Her standing in the art world, though, is immense. It would be hard to find another living artist able to pull off the trick that Ms Dean has done: three shows at once in three of London’s most important cultural institutions, each focusing on a different genre: still-life at the National Gallery, landscape at the Royal Academy and portraiture at the National Portrait Gallery.

Early in her career Ms Dean became known for making enigmatic short films, often displayed in galleries on loop. One project from 1996, “Disappearance at Sea”, dealt with the story of Donald Crowhurst, who vanished from his boat while faking a winning course in a round-the-world boat race. The incident, which happened in 1969, was the subject of a Hollywood film starring Colin Firth released this year; Ms Dean’s treatment of the subject, a mesmeric 14-minute film of a lighthouse at sunset, with no discernable narrative, was decidedly un-Hollywood. More recently Ms Dean has become known for her innovative techniques, 3D-printing special camera parts which allow her to expose different sections of the same film reel at different times, leading to a kind of film collage. Her vast film projection for Tate Modern’s Turbine Hall in 2011 used this method.

Indeed, though she paints, draws, takes photographs and makes installations, Ms Dean is best known for her work using traditional 16mm, 35mm and 70mm photochemical film, a fast-disappearing medium for which she is something of an evangelist. In 2006 she made “Kodak”, a 16mm looping film shot in a French Kodak factory that was then closing down, as consumers turned to digital and stopped buying film in their millions. More parts of the photochemical film industry on which she relies have since been dismantled, including her European developing lab. But her commitment to the medium is far from wavering. “It is different,” she says with uncommon zeal. Her campaign group to save the original cinematic medium has found a high-profile ally in the form of Christopher Nolan, who shoots on film, and who even arranged for his recent blockbuster, “Dunkirk”, to be projected on traditional 70mm in many cinemas last year.

Many films are today shot on film and then edited and projected digitally. But Ms Dean, more hard-line than Mr Nolan, stipulates that all her films must always be shown as film prints on traditional projectors; as a result the halls of her National Portrait Gallery show hum with the sound of over a dozen of these increasingly rare machines, throwing out her films in flickering loops.

Obsessed with this old medium, Ms Dean is often charged with nostalgia. It is a charge she denies. Her art, she says, “deals with what is happening now,” and that she is “not a Luddite”—she has a smartphone like everyone else. It is possible, however, to be nostalgic and not be a Luddite. While Ms Dean’s use of 3D printing proves she is not in protest about the modern world, many of her films certainly have a richly nostalgic feeling to them—being ruminative portraits of ageing artists, writers and actors who themselves represent a fast-vanishing age. These films are certainly elegiac, and occasionally a little bit earnest.

That does not mean she cannot indulge in the occasional joke. Take her film portrait of Claes Oldenberg, a legendary Danish sculptor, seated in his private museum of everyday objects, carefully cleaning a clockwork plastic sushi roll; or that of Michael Hamburger, a poet and translator, talking for just a bit too long about his obsession with apples in the film portrait Ms Dean made of him in 2007.

Indeed “Michael Hamburger” is possibly Ms Dean’s finest film currently on show in London, beautifully and simply shot in the poet’s home on a windy day, as the sun comes and goes through his bay window. It seems hard to argue with Ms Dean’s unwavering commitment to old-fashioned film when the results, in terms of colour, light and shade, are this striking.