Give me a small side order of Cézannes over a great feast of Gauguins any day. This small, perfectly formed survey will surely be noted as one of the best exhibitions this year, the type of exhibition at which the Courtauld Gallery clearly excels: small, tightly focused, and exploring just one aspect of an artist’s output in order to illuminate his practice as a whole.

If you'd been a painter at the time of Impressionism, what would you have done? Rushed to Paris to become a disciple of Manet or Monet? Taken the Symbolist route with Odilon Redon or headed to Brittany to whoop it up with Gauguin and co? No, the chances are you'd probably have got it wrong and, like the so-called Glasgow Boys, hitched your talents to a now virtually forgotten figure like Jules Bastien-Lepage. Jules who? Exactly.

Thomas Lawrence was a child prodigy; from the age of 11 he supported his family by making pastel drawings of the fashionable elite who spent the season in Bath. The next step for an aspiring young artist was to learn how to paint in oils and Lawrence taught himself by doing self-portraits. He learned fast. The first painting in this exhibition of sumptuous portraits shows a diffident 19-year-old sitting sideways and glancing nervously towards us, as though fearful that his efforts will be laughed at.

The full-length version of Olivier Assayas's saga of Ilich Ramirez Sanchez, alias Venezuelan super-terrorist Carlos, was originally a three-part series for French TV and runs to five-and-a-half hours. Even the "short" cinema cut runs to two-and-a-half hours. Yet the director still felt it necessary to preface his opus with the warning that since many of Carlos's activities remained "grey areas" shrouded in mystery and ambiguity, it would be best to regard the film as fiction.

Howard Jacobson, fresh from his Booker Prize triumph, was on an admirable mission last night: to rescue the good name of the Victorians. He wanted us to stop caricaturing our 19th-century forebears as prudish, self-righteous, pompous and hypocritical - you know, the sort of people who were so repressed that they went about covering piano legs in case thoughts should turn to the sensual curve of a lady’s well-turned ankle, but who were also notorious for sexual peccadillos involving underage maidservants, and worse.

People love Canaletto, and the title of this exhibition - which puts the setting of the paintings above the artist who did them - gives a good idea why. Venice as a place and an idea is perennially popular, and Canaletto gives us the big views – the Doge’s Palace, the Grand Canal, the Rialto – in painstakingly literal detail.

Camera-less photography isn’t, as some might think, a 20th-century invention, discovered by experimental Modernists such as Moholy-Nagy and Man Ray. Thomas Wedgwood, before the invention of the camera and at the very beginning of the 19th century, made paintings on glass and placed these in contact with pieces of paper and leather which had been rendered light sensitive with chemical treatments. Where the painted areas blocked the light, the image left its trace. Unfortunately, since Wedgwood lacked knowledge of how to fix the images, the results vanished almost as soon as they appeared.

Contemporary art can, unsurprisingly, become dated pretty quickly – the clue is in the name. Another of Damien Hirst’s mirrored cabinets of pills or of Gavin Turk’s piss-takes of Andy Warhol at the Frieze Art Fair in Regent’s Park is hardly the sort of sight which will enthuse hardened art-gallery goers.

As well as being a great artist, Leonardo da Vinci designed machine guns, tanks and cluster bombs and worked out how to build a submarine; but so appalled was he by the potential of this last invention that he coded his notes to prevent anyone using them to instigate what he called "murder at the bottom of the seas".