I recently purchased a lightweight 70-300 4-5.6 Canon zoom for my 5D. I wanted something for hiking. I was a little concerned that the quality might not be good, but the guys at BH recommended it for this type of recreational use. So far I’ve been really pleased. I have been able to work around low light situations with the ASA. Obviously this lens wouldn’t cut it for pro use, but for something small to have with it’s a fun find.
Here is a bear that I did as kind of a grab shot when I was driving from our camp site at Black Moshannon State Park to State College. It was pretty early in the morning and I thought the lens delivered.