Good stuff mate. The second shot is a tricky situation to expose for. Either you expose for the land, and the sky blows out, or you expose for the sky and the land is black. Your camera has tried to do both, but ended up with a bit of a blown out sky and dark land anyway. You can combat this with a graduated filter which darkens the sky to the same exposure of the land and gives you detail in both. Or, if like me you don't have one, try to find some interesting shapes to silhouette against the nice sky and try to avoid merging them together (overlapping). You can also wait until the sun is below the horizon and is lighting the clouds from below for some great detail and colours. A tripod would help you use a lower ISO setting to reduce noise too. There's a nice article on it in this month's Digital Camera
