First off, I want to say that i am new to the forum although i have been lurking for awhile. I have already learned alot just from looking and i'm sure it won't stop. I recently purchased a canon rebel xsi with two lenses: the 18-55mm ef-s (came with the kit) and a 70-300 mm 1:4-5.6 is usm. I played with the camera a little and it's taking some great pictures. One thing i wanted to do is take a picture where the subject is in focus but everything else is blurry. Reading the manual, it says simply to lower the aperture to 5.6 and you will get the desired blurred background effect. I've tried this several times with no luck at all. I'm sure there is more to it but i'm not sure what i'm doing wrong or if the lens is simply not suited for that type of picture. Any help would be appreciated, thanks!