I am going to a convention in San Diego soon and have been looking for tips for taking pictures. I mostly take pics of waterfalls and flowers, but am wanting to improve my technique with people. I have an XTi and have 24-105 f4 IS Canon and a 50 f1.8 Canon as well. I am renting the Canon 70-300mm f/4.5-5.6 DO IS just to play with. I have an external flash also. I also have a manfrotto tripod and monopod. Wasn't wanting to lug the tripod with me around the convention though... My question is, which lens would you use most of the time to get candids of people in the convention hall? I see advangtages to all of them, and could swap out, but just wanted some tips. I have tried to find some previous threads or links, but nothing that was really covering this kind of event. Thanks for any help.