I currently own 70-200 F4., 24 - 105 F.4., F2.5 50mm macro., and F2.8 20 mm lens ( all Canon). As I am getting little use from the 2.5 50mm macro these days, I am thinking of selling the macro and 20 mm lens to help me finance the Canon F4 17 - 40 Zoom. On one hand it would reduce the number of lens and give me the opportunity of gaining a wider lens that I currently own. But on the other side of the equation , I am really only going to gain a focal length in the range of 17 - 24 mm (I do mainly landscape photos) and loose the advantage of a faster 20mm lens. Any comments would be appreciated.