I'm using a light as an emitter in particular. I have camera and tracking position info that I've brought in from and XSI scene. Everything works great pretty much. The problem is I've parented the Light(emitter) to a null that holds the position tracking data from the scene and I'm having some scale problems. Even when the null is set to like, .5 scale, the size of my particles have to be set to a miniscule value, or else they're HUGE. This is a problem, becease effectively if means, I'm really, really tight on the emitter. Even with the size set to zero on the x, y, and z, the emitter is way to spread out. It's like being really, really close up to an atom. All the parts seem really spaced apart. even though from a normal perspective, they're more densly packed. And I need the light, because I want to be able to animate the emitter on a normal motion path.
Your scene units from XSI get interpreted as pixel values in AE so 1m = 1 Pixel or something like that. A common problem with 3D imports. You can post-scale all your data by using simple expressions like this: