Sci-fi isn’t a highly regarded genre, and with good reason. I first came to grips with crappy science fiction when I was seven years old and wanted to watch “Stargate SG-1” on a Saturday afternoon. I had seen a commercial with lasers and spaceships and Michael Shanks squinting out from his big round ’90s glasses, and I was convinced that this was going to be the best thing I’d ever seen. My father humored me and we tuned in as the frenetic credits sequence started rolling.

The short story: I was wrong. It was not the best thing I had ever seen. I’m not sure my father and I even made it through the entire episode. I learned the important lesson that cool CGI and big guns don’t make something worth watching.

What early experience taught, later experience confirmed. The Star Trek franchise had the benefit of being generally better written and better acted than “Stargate,” but at the end of the day it provided little more than a self-righteous enactment of the now broken fantasies of Great Society-era America. “Babylon 5” was less didactic but more ridiculous. I knew that there was serious science fiction in literature—I’d read “A Canticle for Leibowitz” about five times before I was even in high school—but I had mostly given up on the idea of the well produced science fiction movie, considering “2001: A Space Odyssey” a singular fluke. Then I saw “Blade Runner” and doubled my collection.

Ridley Scott has had some hits, and he’s had some misses—I don’t think anyone has deliberately watched “G.I. Jane” since 1997—but “Blade Runner” is a masterpiece in a category of its own. Harrison Ford, then in his prime, is Rick Deckard, a bounty hunter who specializes in finding escaped replicants—genetically engineered robots who are human in all but their expiration date. The film is set in the Los Angeles of the future: grungy and smog-ridden, controlled by large domestic and foreign interests. This is not the bright IKEA-sleek future of “2001,” or even the alternating plastic garishness and urban decay of “A Clockwork Orange.” This is a future where everything is dark and dirty, and even at midday the sunlight is sick and yellow. In the financial uncertainty of the late 2000s, this looked a lot more like a real future.

“Blade Runner” shows Scott at the peak of his powers as a filmmaker. The careful use of beautifully detailed physical sets and props allows the limited special effects of the 1982 film industry to integrate almost seamlessly with the rest of the film, teaching a lesson that the modern masters of CGI could relearn: The cutting edge techniques of today are the claymation of tomorrow, and nothing can replace a real object in front of a camera. The camerawork itself is gorgeous. Few mainstream films show the same mastery of chiaroscuro that is found in “Blade Runner,” but perhaps the most distinctive feature of the movie is the restraint that Scott shows even as he’s being brilliant. In one scene, Deckard stands silhouetted in front of his apartment window after a fight. He drinks from a glass of water and a small ribbon of blood blooms from his lips into the clear liquid. This tiny detail, a mere drop of food dye, transforms the shot into what is arguably the most beautiful representation of a man drinking water ever made—but it doesn’t draw attention to itself. There is no close-up on the lips, no reaction from characters. It’s left to the viewer to see and to enjoy.

This stands in stark contrast to, for example, the work of Quentin Tarantino, who includes a similar detail in “Pulp Fiction” when John Travolta’s Vincent Vega shoots up. There’s the same backlit ribbon of blood in the clear liquid of the syringe, but Tarantino films it with an extreme close-up. He uses the camera to force viewers to see how clever he is; Scott, on the other hand, seems confident enough in himself and his audience to know that the viewers will notice it on their own.

Ours is an unsubtle era. Our metaphors are obvious and our allegories are simple; the good guys are very good, and the bad guys are inhuman. The noble poor live on garbage heaps and the evil wealthy live in luxury space ships and shoot guns at anyone who approaches them (as in Neill Blomkamp’s “Elysium”). The oppressed struggle from the filthy back of the train to the debauched front of the train (as in Bong Joon-ho’s “Snowpiercer”). All of our images are cartoons: Our action movies are soaked in blood, our romances are soaked in tears. In this ethos, “Blade Runner” holds a quiet majesty. It is a masterpiece that does not blow its own horn, and it is a masterpiece in a genre that doesn’t usually produce masterpieces. That’s why, no matter how many movies like “Prometheus” and “Exodus” Scott makes, he’ll always be one of my favorite directors. He elevated a schlock-driven genre to high art, and he did it without yelling about it at anybody.