While Sigma was quick with the introduction of the Four Thirds system, it lasted until early 2012 before Sigma lenses for Micro FourThirds were for sale. A few weeks ago we discussed the Sigma 30 mm 2.8 EX DN, now it is the Sigma 19 mm 2.8 DN (Neo Digital)’s turn. Both Sigma EX DN lenses are also available with Sony NEX mount.

Construction and autofocus

The body of the Sigma 19 mm EX DN is largely made of plastic, so the Sigma 19 mm EX DN is light, but the mount is metal. There is no distance scale on the Sigma 19 mm EX DN.

Many micro-43 lenses are so small that focusing manually is difficult. But with the relatively broad, ridged focus ring of the Sigma 19 mm EX DN, it is nice to focus manually. For users of polarizing filters or gradation filters, it is nice to know that the lens does not rotate during focusing.

The Sigma 19 mm EX DN is fitted with a linear autofocus motor, which drives the lens elements directly without gears. This ensures accurate and silent autofocus. That is good for both photography and filming. Feature of this design is that internal lenses are loose. If you listen carefully, you can hear it when you shake the lens while it is not connected to a camera. For owners of a Panasonic micro-43 camera: the Sigma 19mm 2.8 EX DN is not equipped with image stabilization.

Vignetting

In practice, you will rarely be troubled by vignetting when using the Sigma 19 mm EX DN. At full aperture, the vignetting is half a stop and some slightly visible vignetting can sometimes appear. From aperture 4, vignetting is 1/3 stop..

Distortion

With a barrel distortion of 1.1%, the Sigma 19 mm 2.8 EX DN scores reasonably. For a lens with a fixed focal length, this is quite something. The distortion is visible to the naked eye. And it can easily be corrected with software afterwards.

Bokeh

In our test, the bokeh of the Sigma 19 mm EX DN showed clear rings in the bokeh, which in practice can translate into a troubled background. Sometimes, the Bokeh looks nice, especially when you are close to a topic. Here is a 100% image cropping of the Bokeh of a nearby shot.

Flare

Sigma claims that the multi-layer coating reduces flare and ghosting and provides a high contrast. This lens is indeed troubled remarkably little by ghosting, even if you do not use the supplied lens hood. We did not even manage to cause ghosting ourselves and flare too was only visible while shooting straight at the sun. For a 19 mm lens, that is a top performance.

Resolution

In terms of resolution, this lens is very good. Even slightly better than the Sigma 30 mm for micro-43. At full aperture, the resolution in the center of the Sigma 19 mm EX DN is already very high, as evidenced by our test. The Sigma 19 mm EX DN reaches the highest resolution in aperture 5.6, after which the resolution decreases as a result of diffraction.

At all apertures, the resolution remains especially in the outer corners behind on the resolution in the center. And the difference seems to be a bit larger in enhanced RAW files than in jpg files. At the edges, the resolution amounts to approximately 80 – 90% of the resolution in the center. This difference is measurable, but not visible in practice. The resolution difference between center and corners is visible to the naked eye.

Chromatic aberration

The chromatic aberration is kept limited to such a level that it will only be visible at large magnifications. It is too bad the chromatic aberration of the Sigma 19 mm EX DN is not on the extremely low level as many other Sigma lenses are, such as the Sigma 105 mm, Sigma 17-70 mm or the Sigma 17-50 mm.

Here is a 100% image cropping of a practical example of chromatic aberration when using the Sigma 19 mm on a micro-43 camera. Chromatic aberration is simple and effective to correct with software, by the way. In Lightroom is a wide range of standard lens correction profiles for Sigma lenses, but during the test there was no profile available for this lens yet.

Conclusion Sigma 19mm/2.8 EX DN review

Pros

• High resolution in the center
• Solidly built and beautifully finished
• Free pouch and lens hood
• low priced

Cons

• No built-in image stabilization
• Reasonable performance in terms of distortion and chromatic aberration
• Resolution in the corners is less than in the center

The Sigma 19 mm EX DN is a lens that is comfortable in the hand, solidly finished and that focuses quickly and quietly. This lens has remarkably little trouble with ghosting, even if you do not use the supplied lens hood. For a micro-43 lens, the Sigma 19 mm EX DN is not very compact, but this is precisely an advantage for those who wish to focus manually.