I haven't seen a trailer for Step Brothers yet, but my guess by looking at the poster is that they are looking to amp up the cheese factor. So one of two things happened here... this thing was shot on normal film (most likely HD cameras ironically enough, since it's all digital it's the easiest to manipulate) and manipulated to look shitty, ala Grindhouse. The other possibility is that it was shot on shit quality film. This could be the case due to the fact that Will Ferrell and/or Judd Apatow movies are gauranteed to rake in skads of cash proportionate to their budget. Cheap film would definately increase the profit to budget ratio, but shitty film may actually be rare these days, so I'm gonna put my money on normal film shitted up on purpose.