Frustration!

[MN Shutterbug]

Cliff, don't be afraid to go all the way to ISO 3200 with the 50D. I shot a basketball game with the 50D and 85/1.8 and the results were quite satisfactory.

[beakgeek]

It looks like the camera locked onto to the signs behind the girls. Notice how in focus the word "Bold" is?

I did some swimming photography this year for my daughter's swim team and ran into this with the divers. Even though I was using center focus point, and tracking the diver, a number of times the back wall would be in focus and the diver was not. When the lens locked on the diver she was in focus. I was shooting with a Canon 40D, with a Canon 100mm f/2.8, ISO 1600, 1/250th at f/2.8. I was not allowed to use flash at any of the venues.

[SanJoaquin]

A newer body that goes to ISO 6400 will solve all your troubles. Getting your shutter speed up around 500 will negate their movements and yours too.

The in camera noise reduction in the newer bodies tames ISO 6400 down good enough for 8x10's.

[Dbl]

CFRay, I am not a big fan of the Canon auto ISO. It can work in certain circumstances but not being able to dial in Exposure compensation is not a good thing. It will work in the auto program and semi-auto program modes (P, Tv, Av) but I don't care for it. It does work better in Manual mode but you are limited at the upper end (no ISO expansion). For low light you often are shooting at the ISO with expansion to get usable shutter speeds so auto ISO really doesn't help.

[Swimmer]

Great discussion guys. Thanks.