Entry is subject to regulations from country of origin. Contact your local South African embassy or representative for more information. Generally speaking visiting crews are divided into an Oversight Group (i.e. client, agency and production company personnel) and the Specialist Group (i.e actors, models, directors, technicians and the art department).
The Oversight Group from visa exempt countries can travel to South Africa without pre-applying at a South African Embassy or Consulate and will be allowed entry by presenting the relevant form, their travel itinerary and a letter from the South African Production Company to the immigration officials at the airport, their passports will then be endorsed with the relevant authorisation.