Sigma 85mm f/1.4 DG HSM Art review: Resolution, dynamic range and distortion
The lens was paired with a Canon EOS 5D Mark III during our Applied Imaging tests.
Resolution
As the results show, it manages to resolve a similar level of sharpness in the centre at f/1.4 as it does when it’s stopped down to f/11. The peak of sharpness in the centre is best at around f/4, with the sweet spot between centre and edge sharpness located closer to f/5.6. Close the aperture down beyond f/11 and diffraction starts to play its part in softening images slightly. Overall, an impressive MTF performance.
Shading
Sigma 85mm f/1.4 DG HSM Art – Shading f/2.0
Sigma 85mm f/1.4 DG HSM Art – Shading f/2.8
The lens shows signs of vignetting (shading) when it’s used at its maximum aperture, with corners appearing approximately 1.3EV darker than the centre at f/1.4. You’ll find corner shading disappears quickly as the aperture is closed down. Corners are 0.5EV darker than the centre at f/2. Close down to f/2.8 you’ll be hard pushed to notice it in real-world images.
Curvilinear distortion
Sigma 85mm f/1.4 DG HSM Art – TV SMIA (%) – 0.1%
The curvilinear distortion performance is just as good as you’d expect for a short telephoto prime. You don’t have to fret about barrel or pincushion causing any issues. As the result from shooting our distortion chart above shows, straight lines appear straight on both the horizontal and vertical axes.
