Finland is celebrating its centenary this year and the National Gallery's exhibition of four paintings by Akseli Gallen-Kalela (1865-1931) of a very large lake in central Finland is a beguiling glimpse of the passion its inhabitants attach to its scenic beauty, in winter darkness and here, summer night. Finland possesses almost 190,000 lakes, depending on your definition.

What does it take to be included in the Taylor Wessing Photographic Portrait Prize exhibition? This year 2,423 photographers entered 5,717 images: 2,373 of those photographers are left wondering what it takes to make the grade. Remarks from the judges are a little on the Delphic side: "Those we have selected provoked a connection that resonated in all of us."  "It’s always tricky to whittle down to the contenders." "We simply nominated our favourite pictures…".

Ilya and Emilia Kabakov’s Tate Modern exhibition features an installation made in 1985 of a Moscow bedsit, its walls lined with political posters. There’s a gaping hole in the ceiling made when the occupant apparently catapulted himself through the roof to escape the incessant clamour of propaganda bombarding Soviet citizens on a daily basis.

Jules Dalou, Edouard Lantéri, Jean-Baptiste Carpeaux, Charles-François Daubigny, Alphonse Legros, Giuseppe de Nittis?

The Imperial War Museum’s Age of Terror: Art since 9/11 brings together art made in response to the immediate events and long-term consequences of the events of 11 September.

Might a painting ever achieve the veracity of a sculpture, a "real" object in space that we can walk around and view from every angle? Could the documentary quality of an engraving ever be equalled by a painting? And how could painting respond to photography – drawing with light – an invention that in the 19th century prompted a thorough reconsideration of painting’s purpose.

Some 50 portraits by Paul Cézanne – almost a third of all those the artist painted that have survived – are on view in this quietly sensational exhibition. Eye-opening and heart-breaking, it examines his art exclusively in the context of his portrayal of people for the first time.

Born into an artistic Swedish-speaking household in Helsinki, Tove Jansson’s first, and most enduring, ambition was to be a painter. Although best known as the illustrator behind the creatures of Moominvalley, those plump white hippopotamus-like folk with an existential longing for adventure, Jansson came to regard her widely successful creations as a distraction from what she considered to be her “real work”.

This is the latest in a line of beautifully curated, closely focused exhibitions that the Courtauld Gallery does so well. Its subject is the great Russian-French painter Chaim Soutine (1893-1943) who, remarkably, has not had a UK exhibition devoted to his work for 35 years.

During his time at the Slade David Bomberg — the subject of a major new retrospective at Pallant House Gallery — was described as a "disturbing influence". The fifth son of Polish-Jewish parents who fled the pogroms, he grew up at the turn of the 20th century in the East End of London where neighbours lived on top of one another and space was scarce.