The artist Ben Johnson has painted every building on the Liverpool skyline in one picture. He painted all 30,000 tiles of the Dome of the Rock, each with seven layers of paint. And he's spent the equivalent of 17 years on one artwork. He is, he admits, a bit obsessive.

For the exhibition Modern Perspectives (8 December 2010 - 23 January 2011), the artist Ben Johnson completed his painting of Trafalgar Square live at the National Gallery. This timelapse captures the 47 days of the exhibition, compressed into less than a minute.

Studio International visited the Alan Cristea gallery to talk to the painter Ben Johnson. This is his second exhibition at the gallery, comprising five new paintings of half-real, half-imagined interiors. Born in Wales, a graduate of the Royal College of Art, Johnson has been making extraordinary hyper-real paintings for around four decades. We asked him about his new works. Interview by MK PALOMAR Filmed by Martin Kennedy

Ben Johnson talks about his latest work, a view of Trafalgar Square from the roof of the National Gallery. Ben Johnson will be completing the painting live in Room 1 at the National Gallery during the course of his Modern Perspectives exhibition.