He had recurring roles in the television medical drama Holby City, as Michael Beauchamp, and New Tricks as DAC Robert Strickland.
His other television credits include the part of novelist Lawrence Durrell in My Family and Other Animals (1987), Pip in Great Expectations and Colonel Fitzwilliam in the 1995 BBC adaptation of Pride and Prejudice as well as Tom Faggus in the BBC adaptation of Lorna Doone.
He has also appeared in episodes of Doc Martin, Foyle's War, Midsomer Murders and Agatha Christie's Poirot.
In 2010, Calf played the Foreign Secretary Anthony Eden in the BBC's revival of Upstairs, Downstairs, reprising his stage role as Eden (twenty years older as Prime Minister at the time of Suez) in Howard Brenton's Never So Good (2008).
In 2019 he played William Wickham, founder of the British foreign secret service, in some episodes of Poldark, series 5.