I have just purchased a canon eos 50d & am having some confusions. i need help desperately! my main point of buying this camera is to do portrait photography. i am most interested in photographing children and newborns/maternity. the lens that came with the camera at the time of purchase is a 28-135mm. when i search online for "newborn photography" or childrens photography" all of the photos that i see are beautifully crisp & clear with very blurred backgrounds. example-- http://img.photobucket.com/albums/v247/Bailey0286/kaphoto.jpg THAT is exactly what I am trying to achieve, however, I'm having a hard time. Do I need to purchase a different lens? I have changed my aperture to the highest number (which it told me in the manual would create a more blurred background) but when I do this, the shutter speed becomes so slow that it takes over 5 full seconds to capture the picture. With children moving around, I don't have that kind of time! Can someone PLEASE help me figure out what I need to do to achieve this beautiful blurred background effect? If i need to purchase an upgraded lens, I have no problem with that, but I don't know where to start. Thank you SO much!