i am newbee here and new to photography tooo. i hope my question is not stupid. I have nikon d90 with kit lens. i am very much interested in bird/wildlife photography and also macro photography. i want to buy good lens also balance my wallet. the option i got Sigma 70-300 APO DG Macro 1:2 @ 200$ Nikkor AF-S 70-300mm f/4.5-5.6G VR Zoom @ 400$ Also i want to know what is Magnification i have seen many photo lens of 70-300mm with magnification 1:2, 1:1, 1:4X like that... can any one suggest which lens i should buy, will sigma help me for both telephoto/macro photography in one lens? if yes will the picture be sharp? Do i need to consider the magnification ratio also while buying telephoto lens? advise me, thanks in advance.