Francis Bacon and Lucian Freud are here to draw in the crowds, but also to set the tone of a Tate Britain exhibition that explores the equivalence of flesh and paint in depictions of the body that even at their most tender and sensual rarely stray far from the brutal and disturbing.

“I start out as an outsider, usually photographing other outsiders, and then at some point I step over a line and become an insider,” wrote American photographer Bruce Davidson. “I don’t do detached observation.” A large number of the images in Another Kind of Life were taken by photographers who took care to befriend their subjects.

On entering the gallery, you are greeted by the cheeping of birds. A flock of zebra finches flies around a circular cage and comes to rest on the branches of the apple tree “planted” in Mark Dion’s latest installation (main picture), before taking off on another circuit. Despite being confined inside an aviary, they seem happy enough; how, though, does one tell?

Colours had meanings for Emil Nolde. “Yellow can depict happiness and also pain. Red can mean fire, blood or roses; blue can mean silver, the sky or a storm.” As the son of a German-Frisian father and a Schleswig-Dane mother, Nolde was raised in a pious household on the windswept flat land on the border on Germany and Denmark that his family farmed.

“Let the light in” has been the fundraising slogan for the two-year project to revamp and modernise the Southbank Centre’s Hayward Gallery, and adjacent Queen Elizabeth Hall and Purcell Room. And that is just what has happened, with two triumphs at the Hayward.

Titian! Mantegna!  Rubens! Dürer! Veronese! Van Dyck! Raphael! Velazquez! About 140 works which were once part of Charles I’s 2,000-strong collection are reunited in a sumptuous collaboration between the Royal Academy and the Royal Collection. It is a marvellous selection covering the 15th to the 17th centuries, the Northern and Southern Renaissance and the baroque.

When I began studying art history, my Bible was Ernst Gombrich’s The Story of Art. The reproductions are mostly in black and white and, thumbing through my dusty old copy, I find a photograph of the Jesuit church in Rome, whose ceiling was transformed by the painter Giovanni Battista Gaulli into a glorious vista of the heavens teaming with cherubs, angels and saints.

It seems they’re having trouble with the lights. Thirty-five past five and they’re not yet on. “Typical,” laughs a woman, surveying the huddle of hi-vis chaperones. Palm fronds wave in the wind, suits leave work. St James’s Square slowly fills with people. The huddle of technicians breaks up and in a short moment, candy coloured bulbs strung in rainbow belts between plane trees light up and everyone goes “Oooooh” and gets out their phone.

In the dark days of January, white cube galleries are luminous spaces. This is especially true of Pi Artworks right now: the Fitzrovia gallery is showing an incandescent array of 23 paintings by Selma Parlour. Taken in at once and at first sight, her abstract works arrest the eye with unlikely chords of colour and angular planes that suggest competing vanishing points.

Art fairs are vaguely promiscuous. So much art, so many galleries, so very many curators. They’re a glut for the eye yet curiously anodyne — the ranks of white cubicles could belong to a jobs fair, except there’s a Miró round the corner. And it’s impossible not to price-perv, that sly flick of the eye down to the label just happens.