Sigma has a superb selection of wide-angle primes. Michael Topham reviews the latest addition

Product Overview

Overall rating:

Sigma 28mm F1.4 DG HSM Art

Product:

Sigma 28mm F1.4 DG HSM Art review

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Price as reviewed:

£1,099.00

Sigma 28mm F1.4 DG HSM Art review: Resolution, shading and curvilinear distortion

Resolution

Sigma 28mm F1.4 DG HSM Art MTF50 on Canon EOS 5DS R

Our Image Engineering MTF tests were carried out with the lens coupled to Canon’s 50-million-pixel DSLR, the EOS 5DS R. The solid red line shows that there’s an improvement when you stop down from the maximum aperture, with centre sharpness peaking around f/4. Corner sharpness peaks slightly later in the aperture range and to find the sweet spot of edge-to-edge sharpness users will want to use the lens at f/5.6. Push beyond f/8 to f/11 or f/16 and you’ll begin to notice softening from diffraction.

Shading

Shoot wide open at f/1.4 and you’ll be able to make out gradual vignetting at the edge, which measures approximately 1.7EV darker than the centre of the frame. Stop down to f/2 and you’ll find it reduces considerably, and by f/2.8 it’s essentially gone altogether. If the vignetting at large apertures disturbs you, it can be fixed in post-processing using programs such as Adobe Lightroom or DxO Optics Pro.

Sigma 28mm F1.4 DG HSM Art @ f/1.4

Sigma 28mm F1.4 DG HSM Art @ f/2

Sigma 28mm F1.4 DG HSM Art @ f/2.8

Sigma 28mm F1.4 DG HSM Art @ f/4

Curvilinear distortion

The results from our distortion tests reveal that the lens does exhibit barrel distortion, however it’s well controlled and crucially doesn’t drop below a figure of -1.0 TV SMIA [%]. The recorded figure (-0.9 TV SMIA [%]) isn’t quite as impressive as the the Sigma 24mm F1.4 DG HSM Art (-0.7 TV SMIA [%]), however you’ll find that the barrel distortion is barely visible in real-world images.

Uncorrected curvilinear distortion, -0.9% TV SMIA

  1. 1. Sigma 28mm F1.4 DG HSM Art review: Introduction
  2. 2. Sigma 28mm F1.4 DG HSM Art review: Features
  3. 3. Sigma 28mm F1.4 DG HSM Art review: Build & Handling
  4. 4. Sigma 28mm F1.4 DG HSM Art review: Image Quality
  5. 5. Sigma 28mm F1.4 DG HSM Art review: Resolution, shading and curvilinear distortion
  6. 6. Sigma 28mm F1.4 DG HSM Art review: Verdict
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