If you've always wanted your 50mm prime lens to be just a little bit wider, Tamron has you covered. Its SP 45mm f/1.8 Di VC USD ($599) has a focal length that almost matches the true normal diagonal of a full-frame camera sensor (43mm).
Very sharp; Minimal distortion; Wide maximum aperture; Optically stabilized; Good close focus capability; Weather-sealed design; Available for Canon, Nikon, and Sony SLRs
Shows color fringing; Edge performance isn't as strong as center; Heavy for its size