Hi and welcome to the Nikonites Community. Lots of friendly folks here who like to talk photography and about their Nikons. If you have any questions I'm sure there is someone here that can help you with answers. That lens, if it's the Sigma 24-70 mm f/2.8 EX DG HSM, then its a full frame lens. Using it on a D80, which is a DX body, you effectively have a 48-140mm lens. It gives you the advantage of being able to upgrade at some point to a full frame body or stay with a DX. When you complete five forum posts you will be able to up load to your gallery. We would like to see some of your work.