Conclusion

The Sigma 30mm F1.4 DC A lens offers quite an unusual standard focal length of 45mm for APS-C DSLRs. It offers acceptable sharpness wide-open at f/1.4 (at least in the centre), excellent build quality, lovely bokeh and fast and quiet auto-focusing, all at a surprisingly affordable price.

The Sigma 30mm F1.4 DC A is tack-sharp in the centre from f/1.8 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 serious chromatic aberrations when shooting wide-open, along with obvious vignetting and some barrel distortion too.

Build quality is excellent, 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 and padded case. The internal HSM focusing proved to be quick and reliable on the Canon EOS 70D that we tested the lens with, and manual focus over-ride at any time is a great feature.

The price of the Sigma 30mm F1.4 DC A is very reasonable for such a fast, well-built lens. We do have some concerns about the image quality, though, particularly when shooting at that appealing f/1.4 maximum aperture, which prevent us from recommending the Sigma 30mm F1.4 DC A more highly.

Ratings (out of 5)
Design	4.5
Features	4.5
Ease-of-use	4.5
Image quality	3.5
Value for money	4