Sigma 18-125mm F3.5-5.6 DC Asp. IF

The Sigma AF 18-125mm f/3.5-5.6 DC is naturally a compromise but the package is a bit more sound compared to its more ambitious sister lens - the AF 18-200mm f/3.5-6.3 DC. Sigma seems to have followed a quite interesting design approach - ignoring distortions and focus on the rest and this works out pretty well. The lens is very sharp specifically around the wide end of the zoom range but the tele settings aren´t bad either. CAs are about average and vignetting could be a little better at wide-open aperture. Nonetheless these are viable compromises for an extremely compact 7x zoom. Unfortunately the AF performance of the lens isn't quite as promising. On the EOS 350D AF accuracy is totally unacceptable when using a focal length below 50mm - I haven't really experienced another lens (besides the 18-200mm) which performs as bad in this respect. Trusting the camera is no good idea here. I used the lens extensively during a recent vacation and after a couple of days I gave up and disabled AF for wide angle shots (Note: normally I'm using the central AF point only for better accuracy ...). The lens may work out better on an EOS 30D or EOS 400D.