Early conceptual art is surprisingly rich in wit and whimsy, and the late British artist and photographer Keith Arnatt had both in spades, quite literally. One of his key works – and part of a new show at Sprüth Magers’ Mayfair branch – is Self-Burial from 1969, a series of nine photographs of Arnatt slowly sinking into the ground. (A German television station showed the piece in sequence twice a day in October that year and it generated a cult following.)

Arnatt, who died in 2008, is probably best known these days for his pictures of the 18 Post-it notes left on the fridge of their Welsh home by his wife Jo – ‘WHERE ARE MY WELLINGTONS, YOU STUPID FART?’, for example. (Jo was suffering from a brain a tumour at the time and Arnatt cared for her until her death in 1996, adding an unbearable emotional charge to the shots, collected in Notes from My Wife.) As a photographer, of dog walkers and their dogs and rotting waste lit like a Renaissance master, he was a key influence on Martin Parr and others. But this new show, ‘Absence of the Artist', concentrates on Arnatt’s work between 1967–72, before he had fully committed to photography and was producing pioneering land art with a conceptual twist as well as more urban interventions.

Mirror-lined pit, 1968, is pretty much as described; an invisible (present but absent) hole or a buried box of strange presences, depending on the time of the day. Portrait of the Artist as a Shadow of his Former Self , 1969–72, is a temporary-but-more-permanent-than-usual silhouette on the pavement. Arnatt’s work seems at once peculiarly British but also aligned with the conceptualists’ wider questioning of art’s purpose and methods – in that he was deadly serious – and the American deadpan of John Baldessari and other masters of words and pictures. Arnatt’s embrace of photography means that he has been, to a large degree, written out of the history of conceptual art. This show should help to write him back in.