Emile Hirsch ain't exactly doing hard time for his Park City assault case ... which might explain why he took one of the most clean-cut mug shots ever.
TMZ obtained the booking photo he took right after pleading guilty Monday for assaulting a Paramount exec in January during the Sundance Film Festival. He got 15 days in jail ... a $4,750 fine ... and 50 hours of community service.
Emile likes the formal look for his mug shots -- as evidenced by the one he took after initially turning himself in to cops. At least he took off his jacket and tie this time.