I'm going to Angel Falls next month, and I want to be able to take some great pics of the falls. I'm looking for a wide angle, and have been looking out for reviews of the recently released Sigma 10-20 f3.5 UWA lens. To all you landscape lovers and wide angle and UWA owners, is an UWA what I'm looking for? Or another lens altogether? I went there about a decade ago, armed only with a 35mm film camera (the cheap, no zoom kind you could buy at Walmart for about 15-20 bucks fifteen years ago), and I needed 3 horizontal pictures to get most of angel falls in a vertical panoramic, and I would still have liked something wider. I currently have my eye on the Sigma 10-20 f3.5 (I'm waiting for the reviews to come out), but I'd like to see what others have to say. The previous version of the Sigma (10-20mm f4-5.6) is about 200 dollars cheaper than the f3.5 version, and the Canon UWA (10-22mm f3.5-4.5) is 50 dollars more expensive than the Sigma f3.5. Currently, I have a Canon XTi, with the 18-55mm kit lens (non-IS version), 50mm f1.4 and 100mm f2.8 macro lens. I've had little luck with the kit lens when shooting waterfalls, and the 50mm and 100mm lenses are way too long to shoot the waterfall with. So, any tips? I've considered getting an UWA for a while now, so this is not a purchase based simply on this one trip.