(Yet another one of those posts.)
Representing claustrophobic situations on screen should be simple enough: you take a person, put them in a confined space, and then you bury them alive. Doesn't matter if they're Buffy (in "Bargaining"):
Or Bones (in "Aliens in a Spaceship"):
Or some character played by Ryan Reynolds (in a dull film I wish I hadn't seen):
Each of those cramped shots communicates to the audience that, like Everett in O Brother, Where Art Thou, someone's in a tight spot. But that's the problem: it communicates the narrow confines in which the characters find themselves, but because the "coffin shot" has become so clichéd, it does so the same way that a sequence of reverse shots inside a car communicates that the participants of a given conversation are driving. Only the oblique angle of the shot of Reynolds comes close to doing what a "coffin shot" is intended to do: duplicate in the audience the claustrophobia felt by the character. (And it only does so because of the odd angle. Most the film uses more conventional "coffin angles" and is as enervated as the other shots above.) Point being: filmmakers are quite proficient at representing people in enclosed spaces and communicating that said people are feeling claustrophobic, but they're not nearly as accomplished at making the audience feel the confinement represented the on screen.
From the examples above, it's obvious that two techniques don't work: 1) placing characters in an enclosed space for a short duration and 2) placing characters in an enclosed space for a long duration. The first falls victim to convention, whereas the second flirts dangerously with boredom. (I disagree vehemently with Ebert on the effectiveness of Buried.) But if acclimation to convention has vitiated the tools with which a director could cajole claustrophobia from the audience (and if said director's not interested in making a tedious stunt of a film), how can an episode or a film be claustrophobic?
The answer is: holistically. By which I mean, burying characters for X-amount-of-claustrophobic-time won't cut it, because that still leaves Y-amount-of-non-claustrophobic-time acting as an atmospheric counterweight. The entire episode or film must be shot with claustrophobia in mind. To use the episode of Bones as an example, too many shots in the episode are scaled too long:
Does this long shot feel claustrophobic to you? Of course not. It's a brightly lit long shot: the lighting (and depth of field) allows the audience to observe details in the fore-, mid- and background, while the scale assures the audience that there's plenty to observe in all those grounds. To think counterfactually for a moment, it's not that shot couldn't be made more claustrophobic. Had the director cropped out some unnecessary visual information:
Still a long shot, but by focusing more narrowly on Agent Booth and the lab technician, the space on-screen seems more cramped. If those officers in the back were to scoot a few feet to the left, the composition of the shot would be more structured, creating an impression in the audience that the characters are bookended or boxed in. Tweak every shot in the episode thus and it'd be possible to create an atmosphere that would inspire claustophobic identification in the audience. ("Sympathetic identification with characters feeling claustrophobic" sounded like too much of a mouthful, but that's essentially what I mean here.)
All of which I write as preface to a post about Andrew Gunn's direction of the Doctor Who episode "Victory of the Daleks," because unlike the above, Gunn seems to understand that claustrophobia is a cumulative effect. More on that in the next post.