Yeah i know will but i have just learnt now that getting the better lens makes a lot of difference. i have used the sigma as well thats what i started with.

24-70 2.8 sigma is a nice lens saying that but make sure you upgrade your firmware on the 350d apparently canon made it so sigma lens didn't quite focus right . then they got cought and had to release it in a firmware update but didn't really advertise it.

told from service agent.