This is a basic template with the purpose of including all arguments / table variables to make it easily known which values can be accessed.
gameevent.Listen( "hltv_cameraman" )
hook.Add( "hltv_cameraman", "hltv_cameraman_example", function( data )
local index = data.index -- The Entity:EntIndex() of the new Cameramen-- Called when a Client becomes the Cameramanend )