London is full of august institutions which, whilst loved by tourists and locals alike, very rarely allow anyone to delve below their public fascade. Frederick Wiseman has made his name making (often) long documentaries capturing the essence of a range of subjects. With titles such as Deaf, Zoo, Meat and Domestic Violence 2, the octogenarian has a passion for pointing his camera into many areas of life. In recent times he’s honed in on Berkeley and the Paris Opera Ballet, and in his new film he peeps behind the doors of The National Gallery.

Filming through 2012, Wiseman covered the period which saw the Leonardo, Titan and Turner exhibitions and much more. Weighing in at just under three hours, National Gallery works on the premise of being an interested bystander. There are no interviews or prompts. Instead the film follows the running of the gallery from board meetings to events, tours and talks. The most fascinating aspects takes place in the bowels of the ancient edifice in the restoration department. Watching the cleaning and rehabilitation of works which are hundreds of years old, as well as discovering valuable insights about their creation, is truly remarkable cinema.

National Gallery is a fascinating insight into one of this country’s most well-loved and culturally important institutions. Ignore the length as the time flies-by.

National Gallery is in cinemas on Friday.