Help me figure out a birthday gift for my documentary loving boyfriend.

My boyfriend doesn't really care to read fiction. He loves behind the scenes and the making of type documentaries.

I've given him the various Star Trek books including These Are The Voages, all three seasons.

Last year I gave him a behind the scenes of the making of Ghostbusters and he loved that.

He likes documentaries about the making of various things, the rise of companies, movies, etc.

He isn't into scandals or celebrity gossip.

I don't know what is out there since I mainly read fiction.

Any suggestions for me?