I have a Canon T3i and will be traveling to Africa in August. The only lens I own is the Canon 18-135mm IS kit lens. I'm not ready to fully commit to purchasing some expensive glass, and therefore going to rent a lens to test it out. I still want to take great pics, so which lens should I rent? The pictures I'm interested in taking are street scenes (markets, people, colors, children)...so street photography and candid portraits as I walk and explore the streets. Since i'm renting, I would like to try out some of the more expensive glass. Or is there a lens that will take care of all my travel scenery needs (i'm guessing my 18-135mm will be adequate for wide angle landscape scenes).