I saw “Tropic Thunder” the other night and it was OK, but what I really enjoyed were the previews, and, no, I don’t mean the hilarious fake previews that are part of the film. There was the preview for “Burn After Reading,” the new Coen Brothers film, and the preview for “Choke,” an adaptation of the Chuck Palahniuk (“Fight Club) novel starring the always-good-but-little-known Sam Rockwell. By the end of these previews, I was practically drooling in my seat. I didn’t want to see “Tropic Thunder.” I wanted to see more previews.

If you ask me, the fall movie season cannot come soon enough. I went to see “Tropic Thunder” not because I was dying to see it, but because I really wanted to see a movie, and it seemed like something I might like, at a time when cinephiles have few options. Late summer is a fallow period for moviegoers; most of the good big summer movies have already been released, and studios are trying to unload uninspired duds such as “The House Bunny” and “Death Race” upon hapless audiences. But come fall the prestige movies start arriving. It’s the start of what I consider Oscar season, because if you’re like me and you like to see all the movies nominated for Oscars in major categories (acting, screenplay, director, film) you’ve got to start paying attention in the fall, when these movies start arriving in theaters. I’m sure it seems crazy, to be thinking about the Oscars in August, and I’ve been accused of being crazy before, but you try watching a dozen Oscar nominated movies in four weeks, which is what I do every February, and you’ll understand why I like to get a head start.

But back to “Tropic Thunder,” which was a decent enough film to watch before the really good films arrive in theaters. The film is basically a parody of Vietnam war movies such as “Apocalypse Now” and “Platoon,” as well as a parody of Hollywood culture. To some, the film might seem a bit too inside (SPOILER ALERT! DO NOT READ ANY FURTHER IF YOU DO NOT WANT TO KNOW WHO PLAYS THE VENAL MOGUL LES GROSSMAN!) — Tom Cruise does a spot-on impersonation of a venal mogul, and British comedian Steve Coogan is very good in an all-too-brief appearance as a rookie director in way over his head — but I enjoyed its take-no-prisoners attitude toward Tinseltown. This stuff was insightful, and funny and had the ring of truth. Because “Tropic Thunder” is often very dumb, although very dumb in a way that is often very funny, I always enjoyed these flashes of wit and intelligence.

Much has been made of the use of the word “retard” in reference to a character played by the dim action star Tugg Speedman (Stiller) in the fictional movie “Simple Jack,” and whether this is offensive, but the movie really seems to be making fun of films like “I Am Sam” and “Forrest Gump” and “Rain Man,” and how big-time actors win awards and nominations for playing mentally challenged people, and making fun of those movies is something I totally approve of. If anything’s offensive, it’s probably Robert Downey Jr.’s portrayal of Kirk Lazarus, a five-time Oscar winner and insufferable Method actor, who dyes his skin black so he can play an African-American soldier. I read one essay wondering why this performance hadn’t inspired more outrage, which you can find here; my theory is that Downey negates most criticism in an excellent and surprisingly subtle performance that suggests how ridiculous this all is. His exchanges with the black actor actor/rapper played by Brandon T. Wright really are funny, and occasionally even smart.

Overall, “Tropic Thunder” isn’t always as funny as it thinks it is, but it never really drags, and the big action climax is a lot of fun. I’d say it’s more of a grab bag of funny moments than a consistently funny comedy, but the funny moments are often very funny, which certainly counts for something. Part of your patience for “Tropic Thunder” will depend on your affection for Ben Stiller, who directed this film. When I asked my friend Bill if he planned to see “Tropic Thunder” he said, “I don’t think Ben Stiller’s funny.” I happen to think Ben Stiller’s funny, which is probably why “Tropic Thunder” made me laugh. But it could have been funnier, and it was so loud and meaningless and dumb that it made me think that fall can’t come soon enough. “Burn After Reading” opens on Sept. 12, and I, for one, can’t wait.