Lens review

Voigtlander Nokton 58 mm f/1.4 SL II

29 September 2010
Szymon Starczewski

4. Image resolution

The resolution test of the Voigtlander 1.4/58 (in the sense of MTF50 values) was based on RAW files from the full frame Nikon D3x. The measurement errors ranged from 0.3 to 1.9 lpmm.

Before we start discussing the Voigtlander’s results let’s remind how its immediate competitors fared in this category. Our tests proved that the combination of the classic 50 mm focal length and the f/1.4 maximum aperture is very difficult indeed. In fact only the Zeiss Planar 1.4/50, the Sigma 1.4/50 and the Pentax 1.4/55 brushed against the decency level here. The classic devices produced by Canon, Nikon and Sony failed to achieve as much; the same was true fro the Pentax 1.4/50. How the Voigtlander compares here? The graph below, presenting its resolution results in the frame center, at the edge of the APS-C sensor and full frame sensor, will help us assess its performance.

Voigtlander Nokton 58 mm f/1.4 SL II - Image resolution

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In the case of the test performed on the D3x the decency level is set near 30 lpmm. As you see the Voigtlander a bit misses the mark. It would be the easiest to compare the tested lens with the Nikkor AF-S 50 mm f/1.4 G, which has been tested on the same body; the Voigtlander prevails because at practically all apertures it gives better results than the Nikkor. On the other hand, though, at almost all apertures it fares a tad worse than the Carl Zeiss Planar T* 50 mm f/1.4 ZF. However it’s worth remembering that the latter was tested on the Nikon D200 and that body produces MTFs about 1-2 lpmm higher than the D3x so in reality the difference between the Zeiss and the Voigtlander is smaller than the mere comparison of appropriate graphs might suggest.

It doesn’t change the fact that by f/4.0 and f/5.6 the results of the Voigtlander are nearly record-breaking . It’s a feature you should expect from a good “prime” lens produced by such a prestigious company and we are pleased in this case the lens didn’t fail to meet our expectations.

At the edge of the APS-C sensor the problems with the contrast you can encounter not only at the maximum aperture but also near f/2.0. Only on stopping down to near f/2.2 you can enjoy a fully acceptable image quality. By f/4.0, though, even at the edge of the APS-C, the resolution results are already very high.

The edge of the full frame is even more demanding; small wonder we have to stop the lens down to f/2.8 to get a useful image. Such a result is a bit better than in the case of the Nikkor AF-S 1.4/50, tested on the D3x which had to be stopped down to almost f/4.0 to get an acceptable image at the edge of the full-frame sensor.

To sum up perhaps the Voigtlander 1.4/58 is not as sharp as the Zeiss Planar but it is noticeably cheaper and its achievements still take it to the top of the1.4/50 lenses class.