Photos: 30 important actors under 30

Hit my radar as Joseph Gordon-Levitt’s helpful half-sister in “(500) Days of Summer” | Proved a keeper helping out the 12-year-old orphan in Martin Scorsese’s “Hugo”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the insistent young woman intent on finding her father’s killer in the Coen brothers’ “True Grit” | Proved a keeper as a sci-fi warrior looking out for the younger kid in “Ender’s Game”  (Carolyn Cole / Los Angeles Times)

Hit my radar as one of Brad Pitt’s sons in Terrence Malick’s ethereal family drama “The Tree of Life” | Proved a keeper as Ellis, a young southern romantic helping Matthew McConaughey’s fugitive in “Mud”  (Jim Spellman / WireImage)

Hit my radar as the young Briony whose act sparks a lifetime of “Atonement” for Keira Knightley | Proved a keeper as the skilled young assassin in action thriller “Hanna” with Eric Bana  (Ricardo DeAratanha / Los Angeles Times)

Hit my radar as Tommy, the popular kid who takes “Carrie” to the prom | Proved a keeper as Gus, half of the romantic couple in “The Fault in Our Stars” with Shailene Woodley  (Bob Chamberlin / Los Angeles Times)

Hit my radar as an unstable teen destabilizing a wedding in “Another Happy Day” | Proved a keeper as the teenage psychopath in “We Need to Talk About Kevin”  (Mel Melcon / Los Angeles Times)

Hit my radar as a teen gangster dealing with a space invader in the horror/comedy “Attack the Block” | Proved a keeper as Ugwu, the professor’s precious houseboy in “Half of a Yellow Sun”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the sensitive pregnant star of ABC Family’s “The Secret Life of the American Teenager” | Proved a keeper as George Clooney’s character’s cynical teen daughter in “The Descendants”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the Ozark Mountain teen defiantly searching for her dad in “Winter’s Bone” | Proved a keeper as an emotionally damaged woman opposite Bradley Cooper in “Silver Linings Playbook”  (Rick Loomis / Los Angeles Times)

Hit my radar playing a Mumbai teen and game show winner strung up for his knowledge in Danny Boyle’s “Slumdog Millionaire” | Proved a keeper as the irrepressible concierge who made the stay at “The Best Exotic Marigold Hotel” delightful  (Ricardo DeAratanha / Los Angeles Times)

Hit my radar as the young female wizard Hermione Granger in “Harry Potter and the Sorcerer’s Stone” and the rest | Proved a keeper as the sultry sister in “The Perks of Being a Wallflower”  (Vera Anderson / WireImage/Getty Images)

Hit my radar in “Panic Room” as Jodie Foster’s character’s daughter having to do or die after a home invasion | Proved a keeper outside of the “Twilight” zone as a moody teenage Joan Jett in “The Runaways”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the persistent kid prodding Hugh Grant’s character toward responsibility in “About a Boy” | Proved a keeper as a zombie falling in love and saving the world in the unexpected delight, “Warm Bodies”  (Craig Barritt / Getty Images)

Hit my radar as an aspiring writer in Southern Gothic witch-teen-romance “Beautiful Creatures” | Proved a keeper as Jasmine’s estranged stepson in “Blue Jasmine”  (Luis Sinco / Los Angeles Times)

Hit my radar as one of Scott’s evil exes in “Scott Pilgrim vs. the World” | Proved a keeper as a residential treatment worker with her own abuse issues in “Short Term 12”  (Ricardo DeAratanha / Los Angeles Times)

Hit my radar as Chekov in new-generation “Star Trek” along with Chris Pine and Zachary Quinto | Proved a keeper as a young man in a long-distance love opposite Felicity Jones in Drake Doremus’ romantic drama “Like Crazy”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the mentally fractured young woman in “Martha Marcy May Marlene” | Proved a keeper as another young woman with a twisted past in Spike Lee’s “Oldboy” opposite Josh Brolin  (Carolyn Cole / Los Angeles Times)

Hit my radar with her good girl pretending to be bad in teen comedy “Easy A” | Proved a keeper as the young writer embroiled in the civil rights-era South in “The Help”  (Robert Gauthier / Los Angeles Times)

Hit my radar as the strong silent Thresh on “The Hunger Games,” protector of Rue, one of the many to fall. | Proved his staying power as the easygoing decent boyfriend of Brie Larson’s blond magnet in “The Spectacular Now”  (Kevin Winter / Getty Images)

Hit my radar as a troubled teen in therapy with Gabriel Byrne in HBO’s “In Treatment” | Proved a keeper as Beat Generation’s Lucien Carr, the troubled one everyone loved, in “Kill Your Darlings”  (Ricardo DeAratanha / Los Angeles Times)

Hit my radar as the recovering alcoholic in love with teenager Haddie Braverman in the NBC drama series “Parenthood” | Proved a keeper as the young African American man gunned down at a Berkeley metro stop in “Fruitvale Station”  (Al Seib / Los Angeles Times)

Hit my radar for her fast patter as the quirky smart pregnant teen in “Juno” | Proved a keeper as a roller derby newbie coming of age in “Whip It”  (Wally Skalij / Los Angeles Times)

Hit my radar as the swoony vampire in “Twilight” | Proved a keeper after playing the arrogant young billionaire in David Cronenberg’s arty “Cosmopolis”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the conflicted Mormon teenager in HBO’s “Big Love” | Proved a keeper after her singing Sophia in “Mama Mia!” with Meryl Streep  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as the tart efficiency expert brought in to work with George Clooney’s firing specialist in “Up in the Air” | Proved a keeper as the therapist falling for Joseph Gordon-Levitt’s cancer patient in the comedy-drama “50/50”  (Jay L. Clendenin / Los Angeles Times)

Hit my radar as a suburban British teen coming of age with the help of Peter Sarsgaards’ playboy in “An Education” | Proved a keeper as a teen destined for death in the sci-fi thriller “Never Let Me Go”  (Ricardo DeAratanha / Los Angeles Times)

Hit my radar as Lisbeth Salander in David Fincher’s English-language version of “The Girl with the Dragon Tattoo” | Proved a keeper as a gauzy Texas gun moll opposite Casey Affleck in the crime/romance “Ain’t Them Bodies Saints”  (Jennifer S. Altman / For the Times)

Hit my radar as a country singer-songwriter scrapping by in “Country Strong” | Proved a keeper as Jack Kerouac’s buddy Dean and their complicated friendship in “On the Road”  (Ricardo DeAratanha / Los Angeles Times)