Bradley Cooper obliges fans with photos at the 'Hangover' premiere. (Jordan Strauss, Invision via AP)
(CBS NEWS) It wasn't all laughs Monday night at the Los Angeles premiere of "The Hangover Part III."
The new comedy serves as the final installment in the "Hangover" film trilogy, and for some of the cast members -- including Bradley Cooper and Ken Jeong -- it's been tough saying goodbye to the series which pushed many of them into the spotlight.
Cooper told reporters at the L.A. premiere that it's been a "bittersweet" time for the cast during the promotional tour of the film.
"We started at the press junket in Vegas and we all sort of were kind of shocked at how emotional it is at the ending of the road. It is nice that we kind of have a two-week tour to ritualistically say goodbye."
Jeong said that starring as criminal mastermind Mr. Chow has changed his life "from black-and-white to technicolor."
"Seeing everyone together, you really get a sense of perspective, that yeah, it is kind of sad."
You can see the Wolfpack in action one last time when "The Hangover Part III"opens in theaters on Friday.
Ken Lombardi, CBS News