I recently got a Canon Digital Rebel XT, a 50mm f/1.8 lens and an extension tube set - 12mm, 20mm, and 36mm . I am still not able to find how to get a good focal length using what I have. The focal length is really narrow, basically most flowers will be blurred at least in one spot when I take a photo, unless the flower is really flat. How can I get quality focus and close up? I can afford another lens but dont know if I need one - any suggestions with working with what I have or suggestions on if I should get another lens?