Carol's opening shot is, while probably not the "best" of 2015, is at any rate one that lays out the tenor of the film to come to best effect. There's a curlicue pattern in metal, almost Art Deco, if not for the dull color, and the camera lingers on it to allow us to appreciate how interesting and beautiful it is, how even in its lack of context, it evokes something about post-WWII design. Then the camera pulls back and we find we've been looking at a grate in a New York sidewalk. It's nothing so crude as a metaphor about finding beauty in places where we're trained not to look for it; Carol deserves better than being reduced to metaphors anyway. But it's a striking metaphor, anyway, to begin a story of lesbian desire in the '50s, and its appeal to the aesthetic construction of space in both the '50s and of movies set in the '50s but shot more recently puts us smack dab in Todd Haynes country.

The director's first feature film in an intolerable eight years is his third project set in the middle of the 20th Century, following the 2002 melodrama Far from Heaven and the ambitious but perhaps not outrageously successful 2011 HBO miniseries Mildred Pierce. It's closer in style to the latter than the former: there's no pastiche of 1950s filmmaking vocabulary to be found in Haynes's directorial style, nor in Edward Lachman's desperately gorgeous cinematography. If the film "looks like the '50s", as it most astonishingly does, that's because of Sandy Powell's brilliant costumes and Judy Becker's smartly fussed-over production design, the latter of which is almost shameless in its ultra-realistic evocation of quotidian spaces - living rooms, restaurants, departments stores (this film's department store scenes are really just the best, reason enough to see the film just to gasp in delight at the deep staging and the highly precise clutter of the set decoration by Heather Loeffler.

The way Lachman shoots these immaculately designed spaces is quite fascinating and weird. It's not Far from Heaven, that's for damn sure. It's an actual film-on-film, rather curiously using Super 16 stock, which would be a remarkably bold choice even if we didn't live in a nearly all-digital age. The grain explodes; the colors blur a little; the blacks get really inky and the fall-off between what is in focus and what is not is unpredictable and extreme. I have been fighting for some long while to put the subjective effect of this style into words, and the best thing I've been able to come up with works like this: so Far from Heaven is shot like a Douglas Sirk melodrama, right? Haynes and Lachman were basically copying that form. Carol is like copying something that doesn't exist: it's like watching a '50s Douglas Sirk Technicolor film noir. Through the lush beauty of the almost floating color palette, there's grotty urban misery baked into the film's look.

Taken as a whole, the visual scheme of Carol seems to me to be working in something like this way: we have a remarkably detailed re-creation of the style and spaces of the 1950s, and we have a film that uses that style to signify meaning in countless remarkable ways (I'm especially tickled by the color-coding of the costumes, which is nothing remotely as blunt as I've just implied, but more a way of literalising emotional states and power imbalances between characters who "own" spaces and characters who do not - take a gander at Rooney Mara wearing a blue dress in a predominately yellow house; complementary colors that nevertheless strikingly stand out from each other), and we have a pair of actresses in Cate Blanchett as Carol Aird and Mara as Therese Belivet who are both enormously good at turning their faces into waxy masks while their eyes work overtime. It's a film about surfaces - but the graininess, the rough contrastiness of the superficially soft and gauzy cinematography, these make it a film also about what is not surfaces.

In other words, it's thematically exactly what you suppose the story about two women falling in love during the Eisenhower administration would be, doubly so when it comes from the director of Far from Heaven, and if there's one thing that tempers my immediate gut response to the film (which was, for the record "This is his second-best film after Safe), it's that Carol is alarmingly straightforward for a Todd Haynes film. What compensates for this is that it's a titanically great version of a straightforward thing. This is a plain old romantic drama, the best one since, easily, Brokeback Mountain (I recently read a fascinating notion that old-fashioned romantic dramas can now really only work as homosexual love stories because there's no other way to effectively put roadblocks in between couples that a 2010s audience will buy. I don't think that I agree, but it's an interesting thought experiment, and of course I've completely lost track of where I read it). Basically, we have here an exercise in building wonderfully convincing characters - Phyllis Nagy's screenplay, adapting Patricia Highsmith's novel The Price of Salt, is a masterpiece both structurally (it presents Therese as the protagonist of the first half, Carol as the second, and makes that contrast feed much of the romantic tension of the whole movie) and psychologically, with immensely persuasive characters built up through highly performative behavior and perfectly-phrased dialogue from women who need to talk around their feelings, like snipers setting up a shot.

For all its visual magnificence, Carol is always most enthralling when it invites us to do nothing but watch and observe: Blanchett and Mara aren't evenly matched (but then, I'm rarely all that persuaded by Mara in anything), but the contrast between Blanchett's formidable control, releasing passion and eros with clockwork precision before closing back under that impenetrable face (which, more than once, is benefited by eye lighting that goes all black in exactly the right way at the right time), and Mara's more tentative, fluttery approximation of the same, fits their characters so well that I can't even say that one is better than the other. Much of the film finds just these two actors responding and crucially not-responding to each other, and it's great.

Though it's certainly a two-woman show, Carol finds room to be impossibly generous to very nearly every human being who appears onscreen. This is especially true of Sarah Paulson's Abby Gerhard (Carol's former lover) and Kyle Chandler's Harge (Carol's soon-to-be-former husband), who are given an unexpected amount of flesh and depth for their apparently functional roles. Harge especially - he's basically the film's bad guy, and we receive him that way, but the script and Chandler and Haynes are so eager for us to understand why he thinks and acts as he does that it's next to impossible not to empathize with him. Both characters are granted a surprising amount of space in the narrative and the images - one of my favorite shots in the film is a wide shot of a restaurant interior, with Paulson visible in a booth and Blanchett hidden off to one side; the scene where they confront each other (the only moment in the film where neither Carol nor Therese is present) is one of those extraordinary flash-points where you realise that there's a whole human experience going on in each of their lives and either of them could be the hero of a film just as rich and nuanced as Carol. It is the greatest kind of humanity in cinema.

This is beyond a doubt one of 2015's most essential movies, and while my brain says that it's of course not for everybody, I sort of can't believe that's true. Yes, there's a level of tight formal control that comes off as slightly fussy; the constant winter settings and the brittle (but also sometimes sentimental) deployment of Christmas and Blanchett's glacial visage all contribute to making it "chilly". Though the opening shots (a car with Therese about to embark on a Remember That Love Affair flashback, the windows just caked with steamy condensation) already point out that this is, after all, a story of how love thaws and warms. Chilliness is no accident - chilliness (and then its absence) are the damn point.

Everything about the film is stately, confident, classical; as the saying goes, they don't make 'em like this any more, but of course they couldn't make 'em this explicitly Sapphic when they did make 'em like this. It's a radical throwback, terrific moviemaking of exceptionally potent emotions and character.