Sigma AF 30mm f/1.4 EX DC HSM (Nikon DX) - Review / Test Report
23 July 2008
Conclusion: It seems the primary design priority for the Sigma AF 30mm f/1.4 EX DC was to achieve the highest possible center resolution without caring too much about the rest. The border performance of the lens is just so-so at f/1.4 and only good when stopped down. Vignetting is high at large apertures and neither CAs nor distortion are overly impressive for a prime lens.
Sigma AF 30mm f/1.4 EX DC (Pentax K) Review / Test Report
23 July 2008
Conclusion: A quite strange design priority but there're applications for this. This is a pretty interesting lens if you want to isolate a (near-centered) object from the rest of the scene using an ultra-large aperture setting. The quality of the bokeh (out-of-focus blur) depends somewhat on the background/foreground structure - it can look "smeary" close to the image borders if the scene is a bit nervous. This is probably a side effect of the low resolution here.
Sigma AF 30mm f/1.4 EX DC HSM - Review / Test Report
22 July 2008
Conclusion: We all know that zoom lenses are compromises regarding speed and performance but we expect fix-focals to perform better than that. Sigma AF 30mm f/1.4 EX DC HSM may perform pretty good in absolute terms but for a fix-focal the lens disappoints a little. The center performance is exceptionally high but the borders are not all that impressive. The other image parameters such as distortions, vignetting and CAs are Okay but nothing to rave about.