Now in its 48th year the veteran photography festival is in better shape than ever. You can walk through the French sunshine to more than 20 exhibitions, hear a talk, meet the snappers and shop on the fringe. It's not just a show; it's a holiday, reaching out to the world, this year notably, to the photographers of Colombia and Iran.

Why is dust so fascinating yet, at the same time, so repellent? Maybe the fear of choking to death in a dust storm or being buried alive in fine sand provokes a visceral response to it. My current obsession with dust comes from having builders in my home over the last seven months.

At heart, Photo London is a selling fair for expensive photographic prints. You wander through the steamy labyrinth of Somerset House from gallery show to gallery show surrounded by black-clad snapperati, assaulted on all sides by images until lost in photography. This year the show is said to be the subject of a "rigorous curatorial process" designed to show rare historical treasures, new work by established masters, and work by the brightest new stars.

This show of work by two artists who use photography to explore the complexities of their own identity has to be the most interesting exhibition ever staged at the National Portrait Gallery, and opening in the same week as International Women's Day couldn't be more fitting.

Lending its name to a major photography prize for the 12th year running, Deutsche Börse has joined the ranks of business organisations known to many for their involvement in the arts rather than what they actually do. Unlike Taylor Wessing or Man Booker, the clue is in the name: German Stock Exchange is reasonably self-explanatory, at least if you speak the language.

These photographs of sand dunes were taken by Brian David Stevens in Balmedie, Aberdeenshire, along a stretch of pristine Scottish coastline. The pictures themselves, while captivating and beautiful in their own right, also have political freight. For it is dunes such as these over which a long and ugly battle raged for several years.

North London’s much loved Estorick Collection is reopening its doors after a five-month spruce up. The Georgian listed building that houses a 120-piece collection of modern Italian art now boasts a new glass conservatory, opened out entrance hall and "daylight-enhanced" gallery spaces. It all bodes well, even if the reliance on a period of prolonged British sunshine to complete the effect feels a touch optimistic right now. Here’s hoping.

The Good American, a Texan no less, has landed at Tate Modern in style. This posthumous retrospective of the great Robert Rauschenberg includes a paint-bespattered, fully made-up bed hung vertically on the wall, and called – you guessed – Bed,1955 (pictured below right). A huge White Painting, 1951 – latex housepaint on seven panels, glossy and smooth – is joined by a huge, swirling, all-black painting, Untitled, c.1951, and an installation of various substances resembling bubbling mud, called Mud Muse, 1968-71.

It’s that time of year again. The National Portrait Gallery exhibits the finalists in the annual Taylor Wessing Portrait prize. The judges have seen 4,303 photographs from 1,842 photographers and now show us 57.

“For me photography is a journey of discovery”, says Elton John. “I buy what I like and if it's not fashionable I don’t care. The more you collect, the more sophisticated your eye becomes.” He realised he had become a serious collector when, in 1993, he paid a record price at auction for Glass Tears, 1932 by Man Ray (main picture). This hauntingly beautiful close-up of a woman’s face is paradoxical because the droplets on her cheeks are obviously glass, yet one still tends to see it as an expression of sadness.