My 3D pdf's all of the sudden are brightly lit and almost over exposed, even when I don't add any lighting at all in Live 3D. I turned off Global lighting before rendering to Live 3D in strata. Maybe I activated feature by accident? I don't know
There are differences in how Adobe Reader 9 handles lighting from how Reader 8 did which can make things look much brighter in 9. We've notified the engineers about this. All I can suggest is that you adjust the lights in Live to get it to look how you want in whichever version of Reader your users are running.