Paramount has released a group photo from the upcoming action comedy Tropic Thunder, starring Ben Stiller, Robert Downey Jr, and Jack Black.

See the image at right and click for larger view.

The new image provides another look at Robert Downey Jr.’s character (that’s him between Ben Stiller and Jack Black), a serious actor who dyes his skin to play a role originally written for a black actor (see First Look: ‘Tropic Thunder’).

In the Ben Stiller-directed flick, a group of actors shooting a big-budget Vietnam War movie get send out into the jungle to face — unbeknownst to them — real-life dangers after the film’s writer and director get fed up with them.

The movie within a movie includes (left to right in photo) novice thesp Sandusky (Jay Baruchel), rap star Alpa Chino (Brandon T. Jackson), pampered action superstar Tugg Speedman (Ben Stiller), Kirk Lazarus (Robert Downey Jr.), an over-the-top Australian-born method actor who has gone to extremes to get into character, gross-out comedy star Jeff Portnoy (Jack Black), and the film’s director Damien Cockburn (Steve Coogan).

Bill Hader and Nick Nolte also star.

An age-restricted trailer for the comedy, which Stiller also co-wrote, was released this week (see ‘Tropic Thunder’ Age-Restricted Teaser Trailer).

Tropic Thunder hits theaters on August 15, 2008.