These were all taken with the Sigma 18-50mm EX Macro. I've been very happy with this lens, and especially for taking in the vast panoramas that a canyon like this offers.
I've only recently realized that there are many other advantages to a wide lens in addition to squeezing more into a frame. I need to do more to explore the kinds of unique vantage points that this lens allows. I didn't really exploit that here, but maybe in some future shots, I'll experiment some more. Meanwhile, I'm open to suggestions.
Nice shots, expecially the second one; I own a 18-50 2.8 too, and I am really very satisfied of it, just think it is one of the best lenses ever made. Also own a canon mount copy for a modified EOS 350D I use to shoot IR: well, I reached the best results in IR just with that lens without focusing problems and really crisp images