Heading his own design studio for over 25 years he has worked as a graphic designer and art director for cultural institutions, publishers and semi-private corporations in the fields of corporate identities, posters, brochures and typography. A long-standing interest in photography resulted in Koeleman more and more choosing to shoot his own images for use in his graphic design work. Over the last five years this has developed into a complete and independent endeavour and his autonomous art work has been shown in many successful exhibitions all over the world.