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Lens review

Sigma A 24 mm f/1.4 DG HSM

8 March 2015
Szymon Starczewski

8. Vignetting

First let’s check how the Sigma 1.4/24 manages when it comes to the vignetting on a small sensor of the Canon 50D. The appropriate thumbnails are presented below.

Canon 50D, f/1.4 Canon 50D, f/2.0
Sigma A 24 mm f/1.4 DG HSM - Vignetting Sigma A 24 mm f/1.4 DG HSM - Vignetting


There are chances to notice that aberration only at the maximum relative aperture where the vignetting reaches 25% (−0.83 EV). Already by f/2.0 the problem disappears almost completely because the value we determined was just 9% (−0.26 EV).

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Now let’s see how the situation changes when you progress to full frame.

Canon 5D III, f/1.4 Canon 5D III, f/2.0
Sigma A 24 mm f/1.4 DG HSM - Vignetting Sigma A 24 mm f/1.4 DG HSM - Vignetting
Canon 5D III, f/2.8 Canon 5D III, f/4.0
Sigma A 24 mm f/1.4 DG HSM - Vignetting Sigma A 24 mm f/1.4 DG HSM - Vignetting


We have to say it looks really grave. At the maximum relative aperture the vignetting gets to 64% (−2.94 EV) – it is a huge level. Still if you remind yourself the monstrous result of the Canon 1.4/24L II, that of −4.4 EV, the Sigma’s performance might start actually looking pretty good. Also the Samyang fared worse than the Sigma but only slightly so, with the vignetting amounting to 65% (−3.05 EV). The Nikkor 1.4/24G fared the best, with that aberration reaching just 54%.

On stopping down the aperture to f/2.0 the vignetting decreases to 41% (−1.54 EV) – it’s still a lot. Only by f/2.8 that aberration becomes moderate, dropping do 22% (−0.71 EV). The problems end by f/4.0 and f/5.6 where the brightness loss in the frame corners amounts to just 13% (−0.39 EV).

It’s clear that, like in the case of the coma, the vignetting is one of the most difficult aberrations to correct in a 1.4/24 class lens. None of the tested devices got even decent results in this category.

Sigma A 24 mm f/1.4 DG HSM - Vignetting