Question....I also have a Canon T3i and take shots of nature and pictures of the strange and wonderful in my travels. Some of the later are people. And sometimes I forego a remarkable shot because the subject is too close and I do not want to intrude. In the third world I often take a quick picture, then show it to then take a picture of their reaction. But this approach isn't always the answer. I need a lens that can capture someone from a distance, and give a reasonably sharp image. The question is: do I need image stabilization? While I understand how desirable it might be, cost is a concern. I would not be able to utilize a tripod in most circumstances.