cjkorb wrote:
Unless your using a tri-pod, the most common problem when shooting at full extension is camera shake. When shooting close up, it's easy to get a shadow from the lens but shooting from 20 feet or more, I can't imagine why you would be getting sporadic shadows on the bottom of your photo's. As far as the focus problem, try using "spot focus" when you shoot at a object and see what it turns out like.
The "focus assist button" makes for a more steady focus. The shadow issue has pretty much gone away for now.
Thank you for your response.