Review Sigma 30 mm f/2.8 EX DN (M43)

22 April 2012

The Sigma 30 mm DN (Digital Neo “) was released in the first quarter of 2012. While Sigma was quick with the introduction of the Four Thirds system, it took a long time before micro-43 Sigma lenses were available. Fortunately change has come. Together with the Sigma 19 mm DN, this is the first lens that Sigma releases for the micro-43 or Sony NEX cameras.

For a few hundred dollars Sigma provides, according to our Sigma 30 mm EX DN test, a well-built lens with the same resolution as the famous Panasonic 20 mm.

The Sigma 30 mm 2.8 EX DN is a standard lens. In terms of angle, a focal length of 30 mm on a micro-43 camera has the same angle as a 60 mm lens on a camera with a full-frame sensor.

Sigma 30 mm f/2.8 EX DN, f/ 5.6

Construction and autofocus

The body is largely made of plastic, so the Sigma 30 mm EX DN is lightweight, but the mount is of metal. There is no distance scale on the Sigma 30 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 30 mm EX DN, it is nice to focus manually. For users of polarizing or gradation filters, it is nice to know that the lens does not rotate during focusing.

The Sigma 30 mm EX DN is fitted with a linear autofocus motor, which drives the lens elements directly without gears. This ensures accurate and silent autofocus, which is pleasant when both photographing and filming. Feature of this design is that the 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.

Image stabilization

The Sigma 30 mm EX DN does not have built-in image stabilization. Owners of an Olympus camera will not be bothered much, because at Olympus image stabilization is in the camera.

Vignetting

At full aperture, vignetting is half a stop and sometimes there will be barely visible vignetting. From aperture 4, vignetting is less than a quarter stop. In practice, you will rarely be troubled by vignetting when using the Sigma 30 mm EX DN.

Distortion

With a barrel-shaped distortion of 0.75%, the Sigma 30 mm 2.8 EX DN scores well. This is not visible to the naked eye in most of the photographs and, if necessary, also controllable afterwards with software.

Bokeh

The lens has a rounded 7-blade aperture, which, according to Sigma, creates an attractive bokeh in the blurred areas of the picture.

In our test, the bokeh of the Sigma 30 mm EX DN showed clear rings in the bokeh, which in practice sometimes translates into a troubled background.

Flare

In terms of design, with only 7 elements in 5 groups, you expect little flare. The Sigma 30 mm EX DN therefore comes without lens hood.

Yet the Sigma performed mediocre in terms of flare and we had to be more careful of flare during our test of the Sigma 30 mm EX DN than during the test of the Sigma 19 mm EX DN, which does come with lens hood, but does not suffer from flare .

Resolution

In terms of resolution, this lens is very good. At full aperture, the resolution in the center of the Sigma 30 mm EX DN is already very high, as evidenced by our test. The Sigma 30 mm EX DN reaches the highest resolution at aperture 5.6, after which the resolution decreases as a result of diffraction.

At all apertures, the resolution at the edges and the outer corners remains behind the resolution at the center. At the edges, the resolution amounts to approximately 80 – 90% of the resolution at the center. This difference is measurable, but not visible in practice. However, the resolution difference between the center and corners is also visible to the eye.

Here is a detail from a photograph taken with the Sigma 30 mm EX DN.

Chromatic aberration

The chromatic aberration is kept limited to a level that it will be visible only at large magnifications. However, the chromatic aberration of the Sigma 30 mm EX DN is not on the extremely low level that many other Sigma lenses show, such as the Sigma 105 mm, the Sigma 17-70 mm or the Sigma 17-50 mm.

Here is a practical example of chromatic aberration when using the Sigma 30 mm on a micro-43 camera. Left the image with a green dot that indicates the place of the magnification, which is also shown. Software-wise, this is easy to adjust afterwards though. In Lightroom, there is a wide range of lens correction profiles for Sigma lenses (for which ode to Sigma), but during the test no profile was available for this lens yet.

Conclusion Sigma 30 mm f/2.8 EX DN review

Pros

High resolution in the center
Solidly built and beautifully finished
Free pouch
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 30 mm EX DN is a lens that is comfortable in the hand, finished solidly and which focuses quickly and quietly. For a micro-43 lens, the Sigma 30 mm EX DN is not very compact, but that is precisely an advantage for those who wish to focus manually. The resolution of this lens is very high, comparable to the resolution of the twice as expensive Panasonic 20 mm. This makes the Sigma 30 mm EX DN a welcome addition to the range of micro-43 lenses.