Yep.. but strangely you can't set the seed in most Poser shaders. I figured out that with an X and Y scale of 128, the noise generated by Poser is exactly 1 pixel each grain. Anything bigger than that and you get rectangular splotches (which looks cool, and would be useful for digital compression errors). Also, if you set the ZScale to .001 * frame_number, that makes the grain change for each frame, giving a passable film grain (Assuming your noise min and max are within reason).