Wow, what a nasty venue. I was in a high school's bubble tonight shooting a track meet. Granted, the indoor setting was nice but the lighting was absolutely horrible. It had a white top which was very dark since it was night. It had a few mercury vapor lights hanging down but the corners of the bubble where the field events were held were very dark. The ambient lighting at ISO 1600 at 2.8 gave me a shutter speed of 1/60 to 1/125. I used an onboard speed light at +3, bouncing it off the top of the dome with manual settings of ISO 1250 2.8 and 1/250. I wasn't real happy with my results but hey, we all have our bad days.