"Amazing Race" Makes the Switch to High-Def

(CBS/AP) "The Amazing Race" will be showcasing its race around the world in HD for the first time Sunday, with an "Unfinished Business" edition starring former contestants.

"For a long time, people have said to me that they couldn't believe we weren't in HD," host Phil Keoghan said. "For me, it was just very frustrating because I didn't disagree with them. I think if there's any show on prime-time network television that lends itself to HD, it's 'The Amazing Race.' It screams for HD, and it's been screaming for HD for a long time."

PICTURES: "The Amazing Race: Unfinished Business"

Several other reality TV shows have been broadcast in HD for years. (CBS' "Survivor" upgraded to HD in 2009.) After years of blaming the expense and challenge of using HD equipment on the road, "Amazing Race" producers made the change for the 18th season, promising crisp images of racers climbing a glacier in Switzerland and interacting with animals in China.

The switch will be seen in the premiere episode, when 11 teams of veteran contestants who have never won the show's $1 million grand prize set off from a wind farm in Palm Springs, Calif., for sunny Sydney, Australia, where the challenges include diving into a murky shark tank and navigating a 16-foot skiff along the glistening Manly Cove.

This season's stops include Yokohama, Japan; Lijiang and Kunming, China; Kolkata and Varanasi, India; Vienna, Austria; Zermatt, Switzerland; and Rio de Janeiro, Brazil. The race also visits Liechtenstein for the first time, where teams were tasked with measuring the landlocked country on mo-peds.

Several game-changing twists return for the "Unfinished Business" edition. In the premiere, Keoghan informs the players that the last team to arrive on the mat will automatically face a U-turn, forcing the duo to perform both Detour challenges, while first-place finishers will receive the Express Pass, allowing a team to skip one task during the race.

The teams returning for their second race are: Bull-riding brothers Cord and Jet McCoy ; goth dating couple Kynt Cothron and Vyxsin Fiala; Harlem Globetrotters teammates Nathaniel "Big Easy" Lofton and Herbert "Flight Time" Lang; sisters Kisha and Jen Hoffman; former cheerleaders Jaime Edmondson and Cara Rosenthal; engaged couple Amanda Blackledge and Kris Klicka; friends Justin Kanew and Zev Glassenberg; mother-and-son Margie and Luke Adams; father-and-son Mel and Mike White; and fathers-and-daughters Gary and Mallory Erwin and Ron and Christina Hsu.