Vaughn made his feature debut last year with Layer Cake, after working as Guy Ritchie's producer on Lock, Stock and Two Smoking Barrels and Snatch.
Vaughn was previously represented by The Paul Weiland Film Company, although he has yet to direct an ad. Earlier this year, he was linked with the agency Beattie McGuinness Bungay.
Vaughn joins a roster that includes the directors David LaChapelle, Paul Hunter, Joseph Khan and Jake & Jim. The company has also signed Alan Friel from TTO.
Exposure Films launched in London in 2002 with backing from the US production company HSI.
The Exposure Films managing director, Nicola Dorling, said: "HSI is our heritage. Many of the US directors have recently shot jobs for UK agencies, while UK talent has been busy Stateside. It's judicious to strengthen our offering into one entity to offer global reach."