The "moon landing filmed in a studio" story, which emerged before the mission series concluded in 1972, has flummoxed me from both ends. The idea that it was really faked is absurd, yet debunking has usually proceeded on technical grounds, such as lighting in the photos, by way of refuting specific claims the conspiracy buffs advance. This seems unnecessary to me.My favourite websites relating to space exploration (and mostly to the Apollo program): Moonbase Clavius, the ultimate Apollo hoax debunking website...
I have no doubt that a quality fake Apollo landing could have been put on in a studio with the technology available in 1969, provided enough money and effort were invested. But how would such a monumental effort be covered up? Hundreds of people would be in the know and inevitably some of them would leak. Meanwhile, NASA and its contractors kept some 80000 staff on the job making the rockets or doing other preparation needed to render the whole shindig convincing. After all, the launches had to be real even if the rockets weren't going to reach the moon, because they were witnessed by the general public on the ground.
This implausibility of eternal cover-up is enough reason for me to reject the conspiracy theory on sociological grounds. The government refused to officially acknowledge the existence of its National Reconnaissance Office, the program responsible for satellite spying on the Soviet Union, although it was public knowledge almost as soon as the first film canisters came down. Nixon couldn't shut the lid on Watergate. The government is able to keep some secrets involving technical or obscure material such as the identities of CIA agents. They cannot keep a major public policy initiative or issue of politics from the news very long.
Much simpler to believe that if we can launch a rocket to begin with, we ought to be able to send it to the moon with a few guys aboard. Do we have to answer the conspiracy buffs point for point, or do we simply assign them the burden of proof?