Sigma AF 18-50mm f/3.5-5.6 DC (Nikon mount) - Review / Lab Test Report
25 July 2005
Conclusion: The Sigma AF 18-50mm f/3.5-5.6 DC is an budget lens which comes with a couple of weaknesses but also surprising strengths. At 18mm the level of distortions and CAs is quite extreme. Vignetting is also an issue at 18mm and 50mm - the latter is quite unusual especially because it doesn't really help much to stop down here.
Sigma AF 18-50mm f/3.5-5.6 DC - Review / Test Report
23 July 2005
Conclusion: The Sigma AF 18-50mm f/3.5-5.6 DC is not a lens without flaws - specifically quite extreme distortions and very high CAs at 18mm as well as soft borders at wide-open aperture at 18mm and 28mm. Nonetheless you can get lots of bangs for your (few) bucks with this lens. If you limit your aperture settings to f/5.6 and smaller the resolution figures are pretty impressive and quite comparable to much more pricey zooms out there.