I am going on a trip to Asia, including Mount Everest, and I was told to make sure to bring a wide angle lens. Currently I have a Canon 40D with the stock EF - S 17-85mm f/4 - 5.6, and a Canon 70-200mm L IS. The only lens I could find wider is a 14mm L series (can't seem to find it on a Canadian site), and the Canon EF-S 10-22mm F/3.5 - 4.5? Is the 10-22mm really going to make that much of a difference over the 17-85mm for width? If not I'd rather spend my money on some other lens... Any suggestions appreciated. Thanks!