Follow Lachlan Goudie ROI, renowned artist and judge of BBC One's The Big Painting Challenge, on a walk-through tour of Dulwich Picture Gallery's new exhibition of John Singer Sargent's watercolours.

'Sargent: The Watercolours' is open to the public 21 Jun - 8 Oct 2017. Find out more and book → http://bit.ly/2tQcQbG