My idea of an indoor sports shoot!

[DerekSalem]

Thanks for the info. I guess, thinking back, that maybe the building was much darker than I thought. I was a ring steward last time so the only pictures I took were with my iPhone when I wasn't working.

I won't be watching any agility or flyball... mostly all leves of obedience and conformation. The upper OB classes will have jumps/retrieves, though... hmm. I was able to get very close to the ring every day I was there, so I'm not sure that I will have to whip out the 70-300mm.

How will a fast shutter speed affect a wide open aperture & a high(ish) ISO? I want to capture the dogs' gaits in the ring, so a slow shutter speed won't work... will it?

Well you're going to *need* a wide-open aperture in order to get your shutter speed fast enough and the scene bright enough...and you'll probably have to max out the ISO (think ISO3200 or ISO6400). Dogs move quickly and the place won't be very bright. You're probably going to need something faster than 1/200s shutter speed (probably around 1/400) which means you'll have to have ISO6400 on your lenses. If you can rent an f/2.8 telephoto it would make things easier.