If you're shooting landscapes or architecture, this lens will surprise you. Of course you have to be careful as he is so vulnerable to the elements. The lens cap cannot be put on this bubble lens. This is an excellent lens for creating a professional image worthy of a calendar or book cover. It captures a huge chunk of the landscape and sky. The Canon 17-40 is a decent wide-angle zoom if you need zoom, but I have both and choose this lens at least 3 times out of 4. When hiking I often have a 14mm and my 24-105 with me. For landscape work, these two are almost always sufficient. Coming home from special places, this lens captures many of my favorite travel shots. Of course, this isn't a portrait lens at all. While it doesn't noticeably distort landscapes and the like, it can make a person look powerful and insane. It's expensive, but because it brings home top-notch images, it's worth the investment for a landscape photographer.