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Lens review

Sigma A 135 mm f/1.8 DG HSM

14 April 2017
Maciej Latałło

8. Vignetting

First let’s check the performance of the Sigma A 1.8/135 on the smaller sensor of the Canon 50D – appropriate thumbnails can be found below.

Canon 50D, f/1.8 Canon 50D, f/2.0
Sigma A 135 mm f/1.8 DG HSM - Vignetting Sigma A 135 mm f/1.8 DG HSM - Vignetting


Even at the maximum relative aperture the vignetting level can hardly be called bothersome, reaching just 19% (−0.61 EV). The problem disappears practically completely on stopping down the aperture to f/2.0 where it decreases to 11% (−0.34 EV); by f/2.8 it becomes completely invisible being just 5% (−0.14 EV).

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Now let’s see how the situation changes on full frame.

Canon 5D III, f/1.8 Canon 5D III, f/2.0
Sigma A 135 mm f/1.8 DG HSM - Vignetting Sigma A 135 mm f/1.8 DG HSM - Vignetting
Canon 5D III, f/2.8 Canon 5D III, f/4.0
Sigma A 135 mm f/1.8 DG HSM - Vignetting Sigma A 135 mm f/1.8 DG HSM - Vignetting


At the maximum relative aperture the brightness loss in the frame corners reaches 42% (−1.56 EV). Even though the result is high, the tested lens actually fares better than the slower Canon and Samyang. The vignetting level of the Zeiss Apo Sonnar was a bit lower but that lens features a slower aperture. If you stop down the Sigma to f/2.0 its vignetting level drops to 31% (−1.08 EV) so it fares better than the Zeiss by f/2.0. By f/2.8 the vignetting problem becomes negligible as it reaches just 12% (−0.37 EV), and by f/4.0 it disappears practically completely (7% and −0.20 EV).

Below we present averaged out values of brightness loss shown in concentric circles as you move further away from the frame centre. The numerical value for every image, expressed in percents, shows the area limited from the top and right by 100% and from the bottom by the presented curve. The area indicates how much light overall is lost due to the vignetting effect. Please don’t mix these percentages with the values given at the beginning of the chapter because they aren’t directly connected.

Sigma A 135 mm f/1.8 DG HSM - Vignetting

f/1.8 f/2 f/2.8


Canon 5D Mk III, JPEG, f/1.8
Sigma A 135 mm f/1.8 DG HSM - Vignetting