Thanks a lot everybody!
1 - I wan't a lens that I can shoot landscapes and also use for shotting weeding and garduations.
2 - For shooting weedings, I believe I need a bright lens (Aperture of f/2.8 or less (2.0, 1.8, etc.))
3 - I wan't a lens that I can use in my Canon 50D, but that will also fit in a Fullframe (that I will buy next year).
Having that in mind, do you have any lens to recommend?
Thanks a lot!!