Harold Lloyd remains the least known of the great silent comedians, little more than an ineffaceable image – the man dangling from the sprung clock of a skyscraper – surrounded by cliches about those beloved American vanities, innocence and gumption. The blame for this public and critical neglect can be placed on the Lloyd doorstep. A savvy businessman who, like Charlie Chaplin and Irving Berlin, maintained ownership of almost all his major works, Lloyd doled out his films in clip shows and infrequent screenings for the better part of four decades, until his death, at 77, in 1971. In subsequent years his estate, administered by his granddaughter, Suzanne Lloyd, has marketed his legacy in theatrical retrospectives, screening on Turner Classic Movies, and even the publication of his 3-D nude photography – the hobby of a wealthy middle-aged man with a lot of time on his hands. Home video, however, has not yet lured her to the trough, and so his films have nothing like the currency of Chaplin’s and Keaton’s.

She may be right. DVDs have permanently altered our experience of the movies, but that doesn’t mean a great deal hasn’t been sacrificed along with the audience. Lloyd does as well by the audience as any filmmaker who ever lived, better than all but a handful. Which is why the four-week Lloyd festival at Film Forum through May 17 – its first Lloyd retrospective in three years – should move to the top of everyone’s cultural to-do list: Even if you could watch “Safety Last” and “The Freshman” to your heart’s content at home, that experience cannot replicate the tribal harmony of laughs and gasps, the collective heart-thumping pleasure of discovering or rediscovering a theatrical legacy of roller-coaster dynamics. The series comprises new 35mm prints of 18 features – 12 silents and six talkies – plus half a dozen of his 100 or so short films.

Some of the critical ambiguity emanates from Lloyd’s generosity in not claiming co-directorial credit. He was undoubtedly as responsible for setting up shots and constructing gags as Keaton – who, in claiming partial credit, at least satisfied the dictates of historians blinded by auteurist posturing. Yet Lloyd is not listed in any directory of directors, not even John Wakeman’s 2,400-page “World Film Directors.” The combination of unavailability and auctorial confusion has relegated Lloyd to a second tier, although it is common wisdom that he was “the third genius,” more popular than his rivals, and sometimes funnier.

It has also led to assumptions that require some revising. As a character, Harold (Harold Lloyd in “Safety Last,” Harold something-else in other films) is justly recalled as an indefatigable go-getter, whose modest attributes are pushed to the breaking point by his vast ambitions. Beyond that, he is encrusted in a few myths – regarding his methods and characterizations – that the work itself invalidates.

Despite Tom Dardis’s 1983 biography, “Harold Lloyd: The Man on the Clock,” which recounts a few of Lloyd’s contradictory explanations of how the 18-minute skyscraper scramble in “Safety Last” was accomplished, several observers hold to Walter Kerr’s insistence that it was all real, as evidenced by an abiding view of the street below. Kerr, in his exceptionally astute (but in this instance credulous) 1975 classic, “The Silent Clowns,” went so far as to argue that the scene works because the audience can trust the veracity of the camera. While it is true that process shots were not in use, Lloyd – though loath to undo a legend that so many wanted to believe – ultimately came clean about his construction of various smaller three- and four-story buildings on hills. Ingenious camera placement and scrupulous editing did the rest.

What fascinates today is Kerr’s need to cling to that myth every bit as tenaciously as Harold clings to the clock, a double metaphor: Harold frantically grasps time and Walter desperately clutches at time lost. Lloyd was undoubtedly an athlete of astonishing skill, rivaled among comedians only by Keaton, who once felt challenged enough to dismiss him as an acrobat. He takes real spills in every picture and climbs trees, fences, and all kinds of vehicles and animals with reckless flamboyance. Where Chaplin will gracefully avoid an open manhole, Harold will always plummet. Where Keaton usually runs from something, Harold almost always runs after something and catches it. He looks like Clark Kent, but his powers are inevitably exposed as superhuman. The idea that he put his life at risk, grabbing for the clock’s minute hand or a rope that slips through his fingers, or dancing on a precipice with a mouse in his pants, is not only quaint but irrelevant. Modern audiences assume that he is somehow safe, and they gasp and cheer and laugh all the same. You haven’t seen “Safety Last” until you’ve seen it in a crowd.

Another myth is that Lloyd is never personally funny – only the gags are. He is a not especially sympathetic everyman to whom funny things happen. Yet no one played chagrin better than Lloyd, and some of the brightest moments in his peak years, between 1924 and 1928, are inserts of Harold registering everything-happens-to-me mortification, as when he mistakes a doughboy’s helmet for a traffic button in “Hot Water” or loses his suit, thread by thread, in “The Freshman.” Perhaps his hapless arrogance in his once widely televised talkies retrospectively robbed his silent self of poetical expressiveness, much as Keaton’s barking voice spoiled the beauty of the great stone face. Lloyd’s most appealing quality is the modesty of his acting, as opposed to the crashing immodesty of his characters. He suffers no pity – I can’t think of a single tear jerking moment. In life, he similarly refused to call attention to the fact that he lost his right thumb and index finger to an explosive; if you watch closely, you can see that he wears a form-fitted glove and does most physical business with his left hand.

The more intriguing received wisdom regarding Harold is his putative niceness, when in fact his characters’ serious flaws primed audiences with points of identification. It’s a stretch to compare him with Macbeth, though not so much if one remembers Mary McCarthy’s description of the Scottish golfer, the murderous Babbitt, prey to over-imagination and delusion. “Function is / Smothered in surmise, and nothing is / But what is not,” could serve as a motto for either man.

Lloyd’s favorite gag, which appears multiple times in each of his films, involves the pitfalls of surmise. Harold is forever confusing one object for another, one man for another, one sound for another, and forever paying the cost. Sometimes the director plays the joke on the audience, as in the opening scene of “Safety Last,” when a prison and noose turn out to be a railway station and mail hook, or during the climactic fight of “The Kid Brother,” when his iron head turns out to be an iron bar. The hero enters “Girl Shy” with his posterior, when a customer mistakes him for a pair of trousers. But usually the joke is on Harold: He ruins two false touchdowns in “The Freshman” because he mistakes a hat for a football and a steam whistle for the referee’s.

Nothing is but what is not. In “Girl Shy,” he pretends to be a great lover; in “The Kid Brother,” a sheriff; in “The Freshman,” the big-man-on-campus football star. In the end, he will become all of those things, but getting there requires the conscience of a narcissist. To get what he wants, Harold steals more cars that one can count, lies, boasts, and leaves other people’s lives and property in a shambles. In “Girl Shy” his pride is so great that, when he thinks his book won’t be published, he punishingly wounds the woman he loves rather than confess his failure. A title card informs us that the town bully hates the innocent he plays in “The Kid Brother” because Harold had once sold him doorknobs as eggs. Yet we identify with him so completely that we usually support the liberties he takes with law and civility. And if we don’t, those fantastic climaxes would close the sale: He rings one variation after another on the big football game or the big fight or the big chase, leaving us all but breathless and very pleased at the outcome.

These climaxes are the most evident examples of Lloyd’s genius at building up a gag; he wastes and wants not. One of his most underrated films, the hour-long “Hot Water,” involves three two-reel situations with Harold and his wife (played by the best and most frequent of his leading ladies, the pixie-like and, when necessary, gimlet-eyed Jobyna Ralston) and her unbearable family. In the first episode, he wins a live turkey and must manipulate it and an armful of packages on a trolley along with a spider and short fused riders. The turkey disappears during the second part, which concerns a new car that is soon demolished, but makes a brief and unforgettable reappearance in the third, when Harold mistakes its claw for the long arm of the law.

If this last section, with its ghosts and constantly misinterpreted dialogue, had been released as a short, it might have become a classic. It is a virtuoso compilation of old and new bits played with relentless speed and savoir faire – and the priceless help of Josephine Crowell, the Canadian born barnstormer said to be born in 1849. She doesn’t look nearly that old (though she is clearly too old to have such young children). She required much stunt doubling, but Lloyd was willing to let his supporting players have a few laughs, and Crowell gets plenty, not least when she rises from bed at the hip, like Boris Karloff in “The Black Cat.”

Many of Lloyd’s gags were imitated in sound comedies, from “Bringing Up Baby” to “Road to Utopia.” Others cannot fail to remind filmgoers of “The Birds” (Harold assaulted by pigeons) or “The French Connection” (a motor chase that narrowly misses a woman and her baby carriage), and literally dozens of other films. I am not suggesting that these moments were copied, only that Lloyd’s films are so copiously imagined that they unfold as a lexicon of movie bits. Lloyd also overtly copied himself, and the replay of “The Kid Brother” fight in his 1932 talkie, “Movie Crazy,” illustrates what he lost when he gained dialogue. Though the scene is played almost entirely without speech, its very possibility weighs him down physically and imaginatively. In the early film, he imprisons the villain in a dozen life preservers and then rows him to shore (not unlike Keaton and the diving suit in “The Navigator”), a nice piece of business – impossible, but believable in a silent film. With sound, time itself is altered, and Lloyd settles for one preserver, this time used to pin down his own arms. Sound ties up the audience, too, telling us more than we want to know about Harold – who, speechless, is whatever we choose to make of him.