Los Angeles news reel photographers holding a party for newly arrived cameraman Dave Oliver after he was talked into starring in a Universal film after he stepped in front of a camera in a moment of desperation a few months earlier.

Dave Oliver is in middle of the photo wearing a fedora. As for who the rest are that I can recognize and identify:

Top row surrounding Oliver: (unknown), Irby Koverman, (unknown),  Mervyn Freeman,  (unknown),  (unknown)
Bottom row kneeling: (unknown), Marshall McCarroll, Sam Greenwald, (unknown)