There are only a few dozen pictures in this exhibition at the National Portrait Gallery. But what the show lacks in quantity it more than makes up for in the quality – and some of its stand-out works are as fine as anything ever put on to canvas. There are marvellous portraits of the literary giants Tolstoy, Turgenev, Chekhov and Dostoyevsky. But the two finest paintings here are of a dying, drink-addled Mussorgsky and of Baroness von Hildenbandt, reputedly the model for Anna Karenina. Both pictures are the work of the realist Ilia Repin. And both are worth the entrance fee alone.