Luis Buñuel on acting 

This is the best 'directing actors HOW TO' on the internet

This is probably the only surviving footage of him speaking Spanish.

¿Alguien ha visto esta tardeada completa? Fué en la Zona Rosa. Yo la ví en algún lado pero no la encuentro. Ya la encontré: Hay otros fragmentos en el documental “A Propósito de Buñuel”

My favourite part of this is how badly Buñuel acts his line

Un aragonès muy talentoso y extraordinariamente vivo que diria el sr Plà.

That´s exactly why it is difficult. Very few people relax enough on camera to do the job right. On the other hand, there´s the lines, movements one must remember while surrounded by the crew and passersby.These factors make relaxing on camera quite a task! CGI is the final solution to the high cost of extras casting, but you can´t make a GCI character play "The Godfather" as well as Brando.

George lucas knows that, CGI is the final solution ...