“You didn’t sit for Lichfield, the session was an event,” said Barry Humphries, launching this exhibition of photographs by his friend, Patrick Lichfield, who died in 2005. His homage to the late Lord followed one given by Joanna Lumley, as she stood in front of an image of herself as a pale, thin girl in a bathing costume in 1965.

Lichfield emerged from an aristocratic military lifestyle into Sixties London. He raced between parties and photo-sessions for Queen magazine on a motorbike, juggling portraits of Chelsea It girlscum-actresses (Lumley, Jacqueline Bisset, Jane Birkin) with young aristos from his original client base. His classiness was a selling point but so too the sensuality of his works, and the quality of prints which reflects all-night sessions, and latterly, digital “improvements” made to some of his classic shots.

The incongruous documentary portraits — a toothless Steptoe character, the East End street trader — reveal Lichfield’s engagement with all his subjects, and their ease with him. He created uniquely informal shots of Marlon Brando and Charlie Chaplin tête-à-tête, the Duke and Duchess of Windsor in Paris, and a relaxed Queen on the Royal Yacht (for American Vogue, in 1972).

Arriving at the dawn of classless pop culture, Lichfield maintained connections with his old world — most fascinatingly in “Ladies at the Schreiber dance, London, 24th June, 1964” where four mature women oversee from sofas a Mayfair dance-floor. Like Jane Austen characters, they purse lips and note details — and he captures their world as astutely as any of the great novelist’s vignettes.

Seventies subjects include Mick Jagger and Bianca Jagger, as well as Kate Bush, but they lack the softly sexual edge of Sixties portraits. Absorbing though this show may be, an exhibition of previously unseen images from Lichfield’s vast archives is overdue.

Until 4 June. Information: 020 7839 7551. www.chrisbeetles.com.