He is most known for his collaborations with film auteurs such as Andrea Arnold, Sally Potter, Stephen Frears, Ken Loach, Noah Baumbach, Yorgos Lanthimos and Mike Mills.

He received Academy Award nominations for Best Cinematography for Yorgos Lanthimos' The Favourite (2018) and Poor Things (2023).

[3] He attended and graduated the Dún Laoghaire Institute of Art, Design and Technology.

[4] Ryan is a frequent collaborator on Andrea Arnold's films, including Wasp, Red Road, Fish Tank, Wuthering Heights and American Honey.

[5][6] He has worked with Ken Loach on the films The Angels' Share, Jimmy's Hall, and I, Daniel Blake.