Ian McKellen has created an unforgettable portrait of a man’s dwindling hours, using his (with apologies to “Lord of the Rings”) wizardly technique to forge a heartrending blend of indignation, sorrow, nobility, and bone deep melancholy.

His King Lear isn’t half bad, either.

When he’s not putting his stamp on the role for gray-bearded stage icons, Mr. McKellen is arguably doing even more with far less as Sorin, the aging landowner who is, by a generous estimation, the fifth- or sixth-largest role in Chekhov’s “The Seagull.” Trevor Nunn’s sporadically stunning but ultimately wearying pair of Royal Shakespeare Company productions at the Brooklyn Academy of Music

have more than their share of questionable conceits and overripe performances. But Mr. McKellen leads by example in both, proving as skillful a fine-tipped miniaturist as he is a towering muralist. Would that more of his collaborators followed his lead. Mr. McKellen, for all his acclaim, has been accused of hiding behind his exquisitely honed craftsmanship at times. And the first few minutes of “King Lear,” a wordless addition by Mr. Nunn in which a tremulous Lear mutely blesses the assembled masses, his eyes rolling back like a mad monk, threaten a reliance on physicality over emotional honesty. Perhaps acknowledging this tendency, Mr. McKellen has turned his king into a man perpetually aware of his wrath but not always in control of it, a tyrant who must grab his own fist to keep from swinging it.

Lear may describe himself as “a man / More sinned against than sinning,” but judging from the way he menacingly removes his belt in the face of slights from his older daughters Regan and Goneril (Monica Dolan and Frances Barber), this is clearly a king who did his share of sinning when he was able. And the jolt of recognition as he tells his Fool (an endearingly shabby Sylvester McCoy) that “nothing can be made out of nothing,” a near repetition of the phrase he used right before exiling his beloved daughter Cordelia (Romola Garai), makes bracingly clear just how often he has spoken or acted with unwise haste in the past.

Sorin, meanwhile, would have you believe that he himself has been made out of — or at least into — nothing. A retired midlevel government official, this fading functionary is ready at the drop of a ruble to list all the regrets and misgivings of his life. He genially suggests to Trigorin (Gerald Kyd), the short story writer who is bedding Sorin’s sister, the vainglorious actress Arkadina (Ms. Barber), that the story of his own life should be titled “The Man Who Wanted To.” (Mr. Nunn and the entire company collaborated on the droll, if somewhat anachronistic, Chekhov translation.) Rallying his diminishing energies for a pathetic trip into town, allowing a flash of lechery to surge through his harmless flirtations with Nina (Ms. Garai), finally whisking himself away from the merry group like a grizzled wolf preparing to die, Mr. McKellen’s Sorin is a devastatingly sad charmer.

But these performances do not take place in a vacuum. Given Mr. Nunn’s grandiose, padded efforts, they seem to take place on a soundstage. “Cinematic” is an adjective often used admiringly when discussing stage direction, but Mr. Nunn tests the limits of this “attribute.” It can be hard to find, let alone suffer with, the characters in his “Lear,” which is stuffed to the gills with torches, table-toppling sword fights, Old Master tableaux (although Christopher Oram’s unit set and Neil Austin’s lighting are beyond reproach), a thunderous musical score by Steve Edis, protracted wordless additions, and extras by the dozen.

And while “The Seagull” is naturally less sprawling — Mr. Edis’s score is confined here to plaintive and rather lovely snippets of chamber music — Mr. Nunn has nonetheless opted to stage the suicide attempt of Konstantin (Richard Goulding) for no apparent reason beyond giving the hordes of servants something to do. He has also conceived of Arkadina, Trigorin, Konstantin, and the rest as an unusually unappealing lot. When the impressionable young Nina (Ms. Garai) swoons with envy at these poseurs, narcissists, drama queens, and melancholics, it’s hard not to think her a bit of a simpleton.

Surprisingly, very few members of the esteemed RSC troupe display equal aptitude at their roles. Ms. Barber’s raspy hauteur as Goneril far outshines her histrionic Arkadina, while Guy Williams’s blustery Cornwall negates his endearingly servile work in “The Seagull.” Ms. Dolan strikes many of the same, rather obvious notes as Regan and the depressive Masha. Only Ben Meyjes and, to a lesser degree, Ms. Garai join Mr. McKellen in succeeding twice. Mr. Meyjes delivers a memorably large-hearted Edgar, who bonds with the crazed Lear in the writhing, debased guise of a hermit, a Caliban to Mr. McKellen’s Prospero (or, if you prefer, a Gollum to his Gandalf). What a treat, then, to see him the next night as Medvedenko, the milquetoast schoolteacher who pines for Masha. Two performances, one broad, one reserved, both wonderful.

But the busloads of ticket holders aren’t heading to Brooklyn for Edgar. They want to see Mr. McKellen, our era’s closest equivalent to Gielgud and Guinness, and they will not be disappointed by either performance. (Note: Mr. McKellen is scheduled to appear in only two of the remaining eight “Seagull” performances; William Gaunt, a fine Gloucester in “King Lear,” spells him the rest of the time.) Lear may have the thunderous soliloquies — and a brief but much-discussed nude scene — but he is not the only “ruin’d piece of nature” brought to stirring life. One is a man who wanted to; the other, a man who wanted to and did and lived long enough to regret it. Both somehow manage to be heard over Mr. Nunn’s unnecessary clamor.

‘King Lear’ and ‘The Seagull’ in repertory until September 30 (651 Fulton St., between Ashland and Rockwell places, Brooklyn, 718-636-4100).