Ken MacGregor — often erroneously spelt "McGregor" in many Doctor Who reference works, including the official BBC website — provided lighting for The Highlanders alongside George Summers.
He had a long career in lighting, having credits spanning the thirty years between 1955 and 1985. He appears to have started his lighting career on The Benny Hill Show and would go on to light some of the biggest British comedy legends, like Ronnie Corbett in The Two Ronnies. He worked on a number of BBC adaptations of classic literature, such as Moll Flanders, with Paul Lavers and Barry Jackson and Jane Eyre, starring Michael Jayston. He also lit famous period pieces, like The Edwardians and The Onedin Line, starring Peter Gilmore and Howard Lang. Furthermore, he was also heavily involved in studio bound "light entertainment" shows like The Black and White Minstrel Show and The Val Doonican Music Show.