Nice shots! I went out today in Stockholm with my dog and my sister to try to get some similar action shots of my dog enjoying the snow, and of us sledding down some hills, but didn't really get any keepers. I was doing 1/250, 50mm f2, and ISO 640 to get proper exposures, but it just wasn't fast enough to get sharp images. I think I have this (hopefully) irrational phobia of going above ISO 800. When I got back I came to this thread and checked your settings, 1/1600! Must have been a bright day. Still, I'm going to try to get outside earlier tomorrow, because it was 1:30-2pm, cloudy, and the sun was already pretty far on its decent for the day. The nights are starting to get slightly shorter each day though