I know this is suppose to be for Canon lenses, but I have a question regarding the Tamron lenses. I have been considering upgrading from the 18-55 IS kit that came with my XSi and wanted to get something better. I have looked at the 17-55 f2.8 IS and am very impressed, but I haven't been able to get myself to purchase it. I just bought the 70-200 f4 IS so spending $900 is a little much at the moment. Eventually, I willget it and use one of these as the backup lens, but justnot now.
My question lies with the Tamron 17-50 f2.8 and the 28-75 f2.8. I don't take landscape pictures and will mostly use this to take pictures of the kids. However I do have a couple of weddings coming up that I will use it for. Does the 17-50 have better optics and performance compared to the 28-75 or are they pretty much the same? Most of the pictures I take will be toward the end of the 17-50 and somewhere in the middle on the 28-75. I appreciate any views that you may have.
Thanks.