i had the tamron 17-50 f2.8 .....had the same proble3m with u, and end up with tamron....anyway with our low noise, just boost up the iso to 800 or 1600 during low light and it settles most of it....sumore u get zoom (some times u realize u need it)..............so go with tamron........unless u really goin for portrait then 50mm would be best......(i see this tamron as a more "general" lens.)