The Tamron 100-400mm f/4.5-6.3 Di VC USD is a light, affordable telezoom lens for full-frame SLRs, but image quality suffers toward the edge of the frame.
Long telephoto reach; Optical stabilization; Fluorine lens coat; Dust and moisture protection; Optional tripod collar available; Relatively light and compact; Affordable.
Soft edge performance at 100mm and 400mm; Vignette at maximum aperture; Some pincushion distortion.