Dennis specialises in aerial photography using fixed wing aircraft and helicopters. Operating out of Atlantic Flight Training Academy Cork Airport, Weston Airport Dublin and Abbeyshrule Aerodrome Longford, he covers the entire island of Ireland. He has also undertaken assignments in New York and Haiti.

Dennis also does aerial photo work for the corporate sector and his clients include: AIB, Commissioners of Irish Lights, Cork City Council, Doyle Shipping Group, Fáilte Ireland, Hooke & MacDonald, PJ Hegarty & Son, Nangle & Niesen, Dublin Port Company, O’Callaghan Properties, OFlynn Group, JCD Group, Cushman & Wakefield.

He has produced four books of aerial photography and is currently working on a fifth.