Buchan was born in Arbroath and studied at Duncan of Jordanstone College of Art in Dundee under Alberto Morrocco. After teaching in various schools, he returned to Dundee as a lecturer. Dennis has studied abroad in New York, Barcelona, Belgium, and Holland. He is now a member of the Royal Scottish Academy. His work fuses Scottish Colourist tradition with more modern, abstract expressionism and pop art, and can be seen in collections in the UK and the USA. His paintings, inspired by landscapes and seascapes, use everyday objects to create bold juxtapositions of form and colour. This is an early landscape entered into a competition in the Royal Scottish Academy in the 1960s.