If one comes away with any certainty from the New York exhibition Frans Hals at the Metropolitan Museum (until 10 October) it is that the Golden Age Dutch master (1582/3-1666) keenly understood and sympathised with his fellow human beings. Whether Hals (beloved of Courbet, Manet, Monet, Van Gogh, Whistler and Sargent) was painting drunks and prostitutes in tavern scenes, humble fisher folk, or burghers and intellectuals and their wives, he unerringly captured the essence of his sitters. There is little sentimentalisation or disparagement in his work.

Lucian Freud, who died aged 88 at his west London home on Wednesday, was often described as Britain's greatest living artist. In the six decades he was active, figurative painting went in and out of fashion - though mostly it was out - but Freud remained resolutely outside and beyond fashion.

In the days before there were any paparazzi to catch celebrities unawares, the pictures of the stars that reached mere mortals like ourselves were carefully staged by the film studios. Establishments like MGM, Warner Bros and Paramount Pictures employed stills photographers to produce atmospheric shots of the action as it unfolded on the set and to make studio portraits of individual actors for release to adoring fans.

Does James Fox fancy himself as the Niall Ferguson of art history? I ask because clearly this latest addition to the growing pantheon of television art historians wants to do for British art what Ferguson sought to do for the British Empire. He wants us to stop apologising, and to admit that we’re simply the best, better than all the rest. And though I grant you he is similarly photogenic (with a touch of that swarthy, swaggering arrogance, too) the ratio of plausible statement to incredulity (my own, whilst spluttering and tweeting my incredulity) was considerably weighted towards the latter.

A subtly haunting and brilliantly composed photograph by André Kertész lives on as a wistfully memorable image of exile: in Lost Cloud, 1937, a small, isolated cloud drifts we know not where next to a New York skyscraper. Kertész is one of the quintet of Hungarian Jewish photographers who are acknowledged as among the greatest of the last century. Kertész, Laszlo Moholy-Nagy, Robert Capa, Martin Munkácsi and Brassaï are the most familiar among the staggeringly accomplished Hungarian photographers who feature in the Royal Academy’s exhibition Eyewitness.

As one of the stars of the Moulin Rouge, she was variously known by the nicknames "La Mélinite", "Jane la Folle", and "L’Etrange". The first was after a brand of explosive, the other two attesting to a little craziness. Jane Avril’s eccentric dance movements evoked the involuntary spasms of female hysteria patients.

How easy is it to stage a dialogue between two artists when they are, in fact, separated by over a century? And is it really an artistic conversation that takes place or merely an imposition of values by the living over the dead? This pertinent question confronts the viewer in an exhibition of two photographers of war-torn Afghanistan. The first, John Burke, took sepia-toned documentary photographs of the second Anglo-Afghan war, from 1878 to 1880 (the first having taken place in 1839-1842), while the second, Simon Norfolk, takes artfully constructed contemporary photographs that blur the boundaries between art photography and documentary.

What ever happened to Ida Kar? If the question is not quite on the level of What Ever Happened to Baby Jane?, perhaps the answer is more interesting, if less melodramatic. Ida Kar - born Ida Karamian in Russia of Armenian parents, resident of Cairo, Alexandria, Paris and Soho, the first photographer to be given a retrospective at the Whitechapel Gallery in its heyday under that curator of genius Bryan Robertson – is now, all too often, known as “Ida Who?” even by those who should know better. So, What Did Happen to Ida Kar?

An artist as inventive and as protean as Picasso, and one who ceaselessly absorbed influences throughout his life, will inevitably present an ever-changing face to the world. Hence, we have an apparently inexhaustible supply of exhibitions devoted to him.