Sigma AF 20mm f/1.8 EX DG RF (FX) - Review / Test Report - Sample Images & Verdict
Lens Reviews - Nikon / Nikkor (full format)

Sample Shots

The following sample shots were taken with a D3x and RAW-converted via CaptureOne.

I apologize for not including really usable f/1.8 shots in the gallery. There are two images shot at that aperture, but in both not really much is in focus, so they do not allow to judge the lens' sharpness across the frame at such a large aperture setting. However, the first f/1.8 shot in the second row illustrates the amount of flare the lens can produce in backlight conditions. In the image in the penultimate row the focus is unfortunately ended slightly behind the sign, but the shot illustrates the large amount of vignetting instead.

Click on a thumbnail to view the original file (opens in a separate window).

Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 160
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/250s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 160
Focal Length 20.0mm
Aperture: f/5.6
Exposure 1/1250s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 160
Focal Length 20.0mm
Aperture: f/1.8
Exposure 1/8000s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 160
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/320s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 100
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/200s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/5.6
Exposure 1/1000s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/640s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/4.5
Exposure 1/800s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/400s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 160
Focal Length 20.0mm
Aperture: f/9.0
Exposure 1/500s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/640s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/6.3
Exposure 1/320s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/5.0
Exposure 1/800s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/320s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/6.3
Exposure 1/500s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/8.0
Exposure 1/200s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/5.6
Exposure 1/320s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/3.5
Exposure 1/2000s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 125
Focal Length 20.0mm
Aperture: f/1.8
Exposure 1/8000s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/4.5
Exposure 1/2000s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/5.6
Exposure 1/1250s
Make NIKON CORPORATION
Model NIKON D3X
ISO Speed 200
Focal Length 20.0mm
Aperture: f/4.5
Exposure 1/640s

Verdict

Just like its slightly longer sister lenses, the Sigma AF 20mm f/1.8 EX DG leaves us with mixed feelings. The center resolution of the lens is very good to excellent, while the borders and corners disappoint especially at large apertures. Vignetting is very pronounced wide open. CAs and distortion are well under control, especially for such a wide lens.

The bokeh is somewhat nervous at large apertures, but improves considerably when stopped down a little.

Unlike its sister lenses, the EX does not feature a moving inner lens tube and consequently doesn't suffer from wobbling. In fact, the lens is very solid and the build quality leaves nothing to complain about.

In summary, the verdict remains the same for all three lenses: not an attractive choice for landscape shooters, but because of the very short minimum focus distance it's an interesting lens to shoot close-ups with wide perspectives. The maximum magnification is lower than with the two longer lenses of the trio, but due to the short focal length the perspective can be more dramatic.

Optical Quality:    
★★★★★
Field Quality:    
★★★★★ (Landscapes)
★★★★★ (Close-up fun)
Mechanical Quality:
★★★★★
Price/Performance:
★★★★★

Click here for an explanation of our star ratings


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