Panasonic Leica Summilux DG 25mm f/1.4

Announced in June 2011 at the same time as the Panasonic Lumix DMC GF3, this lens is the equivalent of a 50mm for a 24 x 36mm frame.
This lens is a rather high-end lens that is intended for those who want to work without using flash even in low-light conditions.
Further, the reduced depth of field inherent to its wide aperture will allow users to isolate their subjects, making this a lens that appears to be ideal for still life and portraits — at least on paper. But it’s important to verify the following points relevant to those particular use cases:

  • Good resolution and uniformity in the field, even at wide aperture.
  • Sufficient brightness.
  • Relatively good control of distortion and chromatic aberrations.

For the moment, DxOMark measurements for the Panasonic Leica Summilux DG 25mm f/1.4 are available for the following cameras:

Measurements for other cameras, such as the Olympus PEN EP3, the Olympus PEN EPM1, and the Panasonic Lumix DMC G3 and GF3 will be available soon.

Panasonic Leica Summilux DG 25mm f/1.4 mounted on an Olympus PEN EPL2

Panasonic Leica Summilux DG 25mm f/1.4 mounted on a Panasonic Lumix DMC GH2

With a DxOMark score of 20 on both the Panasonic GH2 and the PEN EPL2, the Leica 25mm f/1.4 achieves very good results, very close to those of the other high-end micro 4/3 lenses reviewed recently.

As with the M. Zuiko Digital ED 12mm f/2.0 and the M. Zuiko Digital ED 45mm f/1.8, the sharpness for this lens is what it should be on the GH2 and even on the lower-resolution PEN EPL2. So we expect that its results on an Olympus OM-D EM5 will be similar as well.

Strong points Weak points
Optimal use from f/1.4 to f/4 Visible distortion
Very good sharpness, uniform starting at f/2.8 A maximum loss of brightness of 1.2EV in the corners at f/1.4 (but the  flaw disappears starting at f/2.8).
A bright lens Chromatic aberrations visible in the corners
Very good quality-to-price ratio  
Light-weight lens  

Comparisons

Panasonic Leica 25mm f/1.4 vs Olympus M. Zuiko Digital ED 12mm f/2

Here we compare the two lenses on a Panasonic GX1. The uses are different, of course: on the one hand, you have a wide-angle, and on the other, you have a more general-use lens. But still, these 4/3 prime lenses have a lot in common:

  • The same strong points:
    • Good sharpness both in the center and in the field.
    • Good brightness (a T-stop of 1.7 for the Leica and 2.2 for the Zuiko).
  • The same weak points:
    • Distortion a bit strong.
    • Perceptible chromatic aberrations.

As for the housing finish, we prefer the Zuiko. The Leica is mostly plastic (except for the metal mount).

Panasonic Leica Summilux DG 25mm f/1.4 on a Panasonic GH2 vs Nikon 1 NIKKOR 10mm f/2.8 on a Nikon 1 V1

The verdict is in and cannot be appealed: the 12-point difference in DxOMark score in favor of the Leica 25mm puts it clearly ahead of the Nikon 10mm.
As with our review of the Olympus M. Zuiko Digital ED 12mm f/2.0, we regret the lack of lens available on a Nikon 1.

The advantages of the Panasonic Leica Summilux DG 25mm f/1.4:

  • Better resolution and uniformity in the field.
  • Much brighter.
  • A superior quality-to-price ratio.

The advantages of the Nikon 1 NIKKOR 10mm f/2.8:

  • Distortion is better corrected.
  • Half as expensive.
  • 2.5 times lighter and much more compact.

Conclusion

Our measurements of the Panasonic-Leica lens confirm that micro 4/3 lenses are quality optics, with results at least as good as those for entry-level APS-Cs. Still, pay attention to the autofocus speed — the weak point of hybrid cameras (but a priori showing some improvement with the latest Panasonic and Olympus models).

For this lens in particular, the price seems a bit high, so don’t hesitate to take a look at the latest Olympus prime lenses in the same price range (the Olympus M. Zuiko Digital ED 12mm f2.0 and the M. Zuiko Digital ED 45mm f1.8). They have the same optical performance, but a better housing finish. This said, if you want the equivalent of a 50mm lens on your micro 4/3, the Leica is the lens for you — at least for the moment.