I recently bought an SLR camera a few months ago, and am now looking into to getting some better lenses for it. The camera is a Canon Rebel 2000 (EOS 300) and came with a Canon 28-80mm lens. The lens is okay, but not great. I have already decided on a 300mm lens, but not on a replacement for the 80mm one. I have narrowed it down to two lenses. They are the Sigma - 28-135mm F3.8-5.6 IF Macro Lens and the Sigma - 28-105mm F2.8-4 Aspherical lens. Here are links to the Ritz Camera website so you can see some of the statistics: http://www.ritzcamera.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&langId=-1&productId=7465726&topCategory=1004&cat1=1022&cat2=914962 and http://www.ritzcamera.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&langId=-1&productId=7465721&topCategory=1004&cat1=1022&cat2=914962#description. Which one do you think is a better lens? What is most important to me is sharpness, so which one is sharper? How much sharper? Would this lens work well for very close up aviation photography? Would there be any other similarly priced lenses that you think are better? Also, in maybe a year or so, I would possibly like to upgrade to an Elan 7e (EOS 30) if I am really enjoying photography. I like it a lot now, but for me, that is a sizeable investment, so I want to really like it before I buy the Elan 7e. Would those lenses fit the Elan 7e? Thank you very much for your help!