Compared to AF-S Nikkor 50mm f/1.4G

The big question facing potential buyers of the 58mm f/1.4G is how it compares to the much-cheaper 50mm f/1.4G, which on the face of it has a very similar specification, but is much smaller and cheaper. This decision isn't helped by the fact that, if you compare the studio test data of the lenses side-by-side, the 50mm appears to be ahead in some respects - most notably edge sharpness.

Here we're looking at images shot side-by-side on the two lenses under controlled conditions. We've made three comparisons - for sharpness in good light, for coma in night-time shooting, and for the rendition of out-of-focus backgrounds.

Sharpness compared

The rollover below shows how the two lenses compare on the D800. These images were shot on a tripod from the same position, with the lenses focused manually using magnified live view. The Raw files were processed in Adobe Camera Raw, with lens corrections disabled and standardised sharpening applied. Note that the comparison is slightly complicated by the difference in focal lengths - the crops from the 50mm are lower in magnification and come from closer to the centre of the frame - but that's unavoidable in this case.

Roll your mouse over the aperture labels to see the corresponding images, with 100% crops taken from the centre, edge and corner of the frame. Click on any image to download the full-resolution file.

AF-S Nikkor 58mm f/1.4G
F1.4
F2
F2.8
F4
F5.6
F8
F11
F16
AF-S Nikkor 50mm f/1.4G
F1.4
F2
F2.8
F4
F5.6
F8
F11
F16

The differences here are quite subtle, but some clear conclusions can be drawn. Both lenses give somewhat imperfect images wide open, but the 50mm is distinctly soft and hazy. The 58mm, in contrast, offers higher contrast, but at the cost of some visible magenta fringing from longitudinal chromatic aberration.

Both lenses improve dramatically on stopping down to F2, but the 58mm is visibly sharper all round. Stop down to F4 and it's clear that the soft corners predicted for the 58mm in chart testing aren't relevant for this three dimensional, distant subject - if anything the 58mm is outperforming the 50mm, rather than the other way round. Neither lens has any serious problem with lateral chromatic aberration, but there's a hint of colour fringing in the corner crops from the 50mm that's just not present with the 58mm.

Probably the most interesting information, though, comes from the fine detail in the foliage towards the edge of the frame (centre of the three 100% crops). Here the 58mm shows a dramatic advantage over the 50mm, even when taking the difference in magnification into account. The 50mm needs to be stopped down to F5.6 to pick out all the detail here; the 58mm matches it at about F2.8.

The take-home message here is that, with sufficiently dedicated pixel-peeping, we can see a real advantage for the 58mm over the 50mm in terms of sharpness. But we really do have to look closely.

Night-time comparison: Coma

In our second comparison we've taken the same set of shots a few hours later. The aim here is to look at coma and astigmatism - aberrations which cause point light sources towards the edge of the frame to flare out. Nikon says that the 58mm has been specifically designed to minimise this - let's see what this means in practice. Here we're taking crops from bright light sources towards the edge of frame - again with the 50mm these come from closer to the centre, which places it an advantage here.

Scene overview (AF-S Nikkor 58mm f/1.4G, F1.4)
AF-S Nikkor 58mm f/1.4G
AF-S Nikkor 50mm f/1.4G
F1.4, 100% crop F1.4, 100% crop
F2, 100% crop F2, 100% crop
F2.8, 100% crop F2.8, 100% crop
F8, 100% crop F8, 100% crop

This is one area where the 58mm surpasses the 50mm comfortably. Instead of flaring out dramatically at large apertures, point light sources are rendered much closer to circular. This means that the 58mm can be used wide open with much more confidence in these situations, and should also make it well-suited to demanding applications such as astrophotography.

For both lenses, stopping down beyond F2.8 does little to reduce coma any further, but instead results in 18-ray star patterns from the 9-bladed aperture diaphragm.

Portrait comparison - bokeh

The third comparison we're going to make regards the two lenses' rendition of out-of-focus areas of a scene, or 'bokeh'. This is an important consideration with fast primes, which are frequently used to give subject isolation against a blurred background. In the example below we've shot the two lenses from the same position at a series of apertures. But this time, rather then taking 100% crops, we've simply take crops from the corresponding area of the background for both lenses.

Scene overview (AF-S Nikkor 58mm f/1.4G, F1.4)
AF-S Nikkor 58mm f/1.4G
AF-S Nikkor 50mm f/1.4G
F1.4, background crop F1.4, background crop
F2.8, background crop F2.8, background crop
F5.6, background crop F5.6, background crop

Again the differences here are rather subtle, but the 58mm does a better job of smoothly blurring-away this particular area of the background. This is most noticeable with the F1.4 shots - the 50mm version looks noticeably 'busier' - but it persists to some extent as you stop down, too. This is easiest to appreciate by downloading and comparing the full-size images; there's nothing obviously wrong with those taken using the 50mm, but those from the 58mm just look nicer.

We noted the 50mm F1.4G's relatively attractive bokeh for its class in our review of that lens, and the 58mm takes this desirable characteristic just that bit further.