both my tamron purchases have had drawbacks, the 90mm macro can give a false low battery warning with the d90, (a known issue). plus i bought the 11-18mm wide angle zoom. crappy resolution and sharpness, pasty colours and a hell of a lot of white fringing on the edges of most subjects. also, when using it,on some shots i noticed what i thought was sensor dust on my pics, switched to another camera and they were still there. something between the lens elements? i wouldnt waste my cash on another tamron thats for sure!