Tokina AT-X 107 DX Fisheye AF 10-17mm F3.5-4.5

Fisheye lenses are special effect items so the sheer optical quality is not really a primary aspect. However, the Tokina does generally a very good job. It sharp enough for its purpose and the high degree of barrel distortion is naturally a feature to enjoy and not a bug. However, the Tokina lens clearly has some downsides. The primary weaknesses are chromatic aberrations (color shadows at the borders) and, more so, purple fringing (color blooming). Lateral CAs can be reduced easily via imaging tools but this is more difficult with PF. Compared to similar products such as the Nikkor AF 10.5mm f/2.8 DX or Olympus Digital Zuiko 8mm f/3.5 the price of the Tokina lens is very attractive at around 500€/US$. The Tokina has a superb build quality. Typical for fisheye lenses it's a hell of a fun to use but remember that this is not a mainstream lens like conventional (corrected) ultra-wide lenses.