Conclusion

The Sigma 30mm F1.4 DC DN C lens offers quite an unusual standard focal length of 45mm for APS-C compact system cameras and a slightly longer 60mm for Micro Four Thirds cameras. It offers acceptable sharpness wide-open at f/1.4 (at least in the centre), good build quality, nice bokeh and fast and quiet auto-focusing, all at a very affordable price.

The Sigma 30mm F1.4 DC DN C is tack-sharp in the centre from f/2 onwards, although you need to stop down to f/4 to get acceptable results at the edges of the frame. Disappointingly the lens does suffer from obvious chromatic aberrations when shooting wide-open at f/1.4, along with some vignetting, although stopping down to f/2 almost completely removes the purple and green fringing that is so prevalent at f/1.4.

Build quality is very good, with the brass lens mount and sober all-black design adding to the high-quality feel, and Sigma have even generously included a very good circular lens hood. The auto-focusing system proved to be pretty quick and reliable on the Sony A7R II that we tested the lens with, and manual focus over-ride at any time is a great feature.

The modest asking price of the Sigma 30mm F1.4 DC DN C is very reasonable indeed for such a fast, well-built lens. We do have some concerns about the image quality, particularly when shooting at that headline-grabbing f/1.4 maximum aperture, but overall the Sigma 30mm F1.4 DC DN C is well worth considering.

Ratings (out of 5)
Design	4.5
Features	4
Ease-of-use	4
Image quality	4
Value for money	4.5