Charles and Camilla toured High House Production Park where students from South Essex College are taught a range of subjects.
They watched teenagers learning how to light a music performance - featuring a drummer, keyboard player and violinist - and make sure the sound levels were right.
Later they joined a Technical Theatre class where students were researching films and looking at the film career of Peter Sellers.
Megan Carey, 16, chatted to the Prince - a life-long fan of radio comedy show the Goons which featured Sellers - and said afterwards: "He seemed quite interested in what we were doing. He said to me 'you need to watch all of his films'."
Charles is patron of the Royal Opera House and in its cavernous production workshop he saw huge backdrops for productions and painted panels that will create the effect of a wood panelled room for a performance of Falstaff being staged in Amsterdam later in the year.
Alex Beard, chief executive of the Royal Opera House, said: "The prince was hugely impressed, this is probably the best production facilities available to any opera house in the world - in terms of its scale, facilities and available natural light."