I am going to the Vince Shute Wildlife Sanctuary to view the black bears here in a week. I have been there before and always come away unhappy with my shots. This time I will be using my new-to-me 40D with a Tamron 70-200mm 2.8 lens. I also have the Sigma 150-500 but from times past the 70-200 was always enough to get as close as I wanted. However, I never liked the exposure. The faces were always too dark or slighly blurred. I don't remember what settings I used last time I was there but this time I am thinking of going center-weighted with my metering and maybe 200-400 iso to freeze action since they never stop moving.