|
I haven't read anything that said Tamrons can't AF, the knocks on Tamron and Sigma lenses are that they don't AF as fast as the Canons. I've read very good reviews on Tamron 17-55mm f/2.8 and WA on Sigma and Tokina.
My suggestion is that spend sometime reading forums such as: dpreview.com (xti forum), photozone.de and fredmiranda.com
These sites should give you plenty of reading on users take on equipments and lenses. Check the vendor on reselleratings.com before buying your equipments if you are not familiar with them.
The easiest camera to use personally is the Nikon D50 with the 18-200mm VR (all around) and Sigma 105mm macro lenses.
Buying the camera is the easy part getting lenses is another story. Nowadays people probably change a camera in 3 yrs and if you don't like your camera you can get a new one in about 18 months (Canon upgrade their line in about 18 months) but the lenses will be with you for a long time.
Good luck with your selection.
|