Nikon Z 24-120mm f/4 S Review

Focusing

If you’re already familiar with the Nikon Z system, there’s not much to say about the Nikon Z 24-120mm f/4 S’s focusing performance. It’s just as fast and accurate as expected – which is to say, excellent on both counts. Whether because of the camera, the lens, or both, Nikon’s mirrorless system provides better pixel-level autofocus precision than Nikon DSLRs ever did (even if both are used in live view).

It’s especially obvious when I test lenses in the lab. The autofocus of Nikon Z lenses always hovers closely around the “perfect” point that maximizes our sharpness figures in Imatest. Of course, I still double-check things by focusing manually with macro rails, but my optimized results are usually only a hair better than the autofocus results. By comparison, DSLR autofocus has a much wider spread, even when using contrast-detect AF in live view.

The Nikon Z 24-120mm f/4 is no exception to this rule. As long as autofocus finds your subject, your subject will be sharp. The 24-120mm f/4 S also has no meaningful focus shift at any focal length in my testing (where the focus point changes as you change your aperture), which makes your job even easier when focusing.

Like most midrange zooms, the Z 24-120mm f/4 S is a varifocal design rather than a parfocal design. In other words, the focus point changes as you zoom the lens to different focal lengths. So, it’s best to zoom to your preferred composition before focusing – not the other way around. (Still, the Nikon Z 24-120mm f/4 S doesn’t change focus too dramatically upon zooming, so you can get away with small focal length changes without the need to refocus.)

Vignetting

The Nikon Z 24-120mm f/4 S has solid vignetting performance. As expected, its worst performance is at f/4 and 24mm. At most focal lengths, there’s just a hair more vignetting at infinity focus (IF) than close focus (CF), but it’s not enough of a difference to matter. Here’s the full vignetting chart, with the numbers measured in stops of light:

Any vignetting under one stop is negligible in my book, and anything under 1.5 stops doesn’t need to be corrected in post-processing most of the time. Wide open at f/4, the Nikon Z 24-120mm f/4 S does well at every focal length except 24mm, where it has more vignetting than I’d like. Stopping down to f/5.6 and especially f/8 makes vignetting a non-issue.

This is slightly better performance than the Nikon Z 24-70mm f/4 S at every focal length, which is not bad considering that the Z 24-120mm f/4 S is a more complex lens with a greater range of focal lengths. For context, here’s the Z 24-70mm f/4 S’s vignetting chart:

Against a blank field, here’s how the vignetting looks on the Z 24-120mm f/4 S under the worst conditions (24mm, f/4, close focus):

Better performance would have been welcome, of course, but this isn’t so bad. In real-world images, it will be less obtrusive than this, since subject details always obscure vignetting somewhat. Not to mention that a bit of vignetting is welcome for many photos.

Even so, if you’re an Adobe Lightroom user, I recommend turning your in-camera vignetting correction to medium or high (yes, even if you shoot RAW rather than JPEG). This signals Lightroom to apply a vignetting correction profile to your Nikon Z photos by default. Otherwise, you’ll need to fix any vignetting manually – without the lens-specific profile. It’s a time-saver to do it this way.

Distortion

Some distortion is always expected on a wide-to-telephoto zoom – usually signifiant barrel distortion at the wide end and pincushion distortion at the long end. The Z 24-120mm f/4 S is no exception. Here’s the progression of distortion at different focal lengths:

This is more distortion than I’d like, especially the 5% barrel distortion at the wide end. That puts the lens at a similar level as the Z 24-200mm f/4-6.3 VR and Z 24-70mm f/4 S, which max out at 5.82% and 4.43% distortion respectively. That isn’t a good thing. By comparison, the Nikon Z 24-70mm f/2.8 S keeps distortion under 3% at all focal lengths.

Especially with their more complex zooms, Nikon has been pushing high-distortion lens designs in recent years. Granted, their reasoning makes sense: Distortion is one of the easier lens flaw to correct in post-processing. When you stretch the image straight, you lose a bit of sharpness (especially in the corners), and the composition must be cropped a bit. But those issues are usually pretty minor. A lens that’s already sharp can handle it.

Interestingly, a lot of photographers will never notice this lens’s distortion, even if they shoot at 24mm and photograph something with straight lines, like architecture. That’s because Nikon automatically applies a distortion correction profile to the 24-120mm f/4 S by default – so, you always see straight lines when you’re composing the photo in-camera. On top of that, Nikon and Adobe apply a distortion correction profile to this lens in post-processing software, which cannot be disabled.

Ultimately, if you use Lightroom or Photoshop for photo editing, you may never see the Z 24-120mm f/4 S’s distortion in your photos at all. But it’s still there in the lens’s design behind the scenes.

Chromatic Aberration

The Nikon Z 24-120mm f/4 S does a reasonable job minimizing chromatic aberration, especially for a zoom, but it’s still visible under some conditions. Here’s the chart of lateral chromatic aberration at different focal lengths and apertures:

Rather than the small differences at various apertures, the more relevant consideration in this case is focal length. The Z 24-120mm f/4 S has the highest levels of lateral CA around 24mm and 35mm. It dips as you zoom to about 70mm, then increases a bit at the long end of the zoom range.

At the absolute highest, the lateral CA on the Nikon Z 24-120mm f/4 S measures 1.76 pixels in our tests. That’s better than the Z 24-200mm f/4-6.3 (2.64 pixels) and F-mount 24-120mm f/4G (2.85 pixels) but worse than the Z 24-70mm f/4 S (1.22 pixels) and Z 24-70mm f/2.8 S (1.17 pixels). So, it’s around the middle of the pack among Nikon’s midrange zooms.

In real-world photos, this most commonly manifests as a small purple fringe around high-contrast subjects like tree branches. Here’s an example photo from 24mm and f/16, cropped from the top-left corner. This crop is so extreme that you don’t need to click on the image to enlarge it; it’s already full-size:

So, not a bad performance, but there’s still some chromatic aberration there. Some Nikon Z lenses – both primes and zooms – have such low chromatic aberration that it’s never visible in real-world photos. Even so, this level is easy to correct in post-processing without leaving obtrusive artifacts behind.

Another type of chromatic aberration is the longitudinal variety, where out-of-focus regions behind your subject turn green, and out-of-focus regions in front of your subject turn purple. The Z 24-120mm f/4 S has mild longitudinal chromatic aberration. In the following crop, notice how the background blur in front of the focus point is a bit more purple, and the blur behind the focus point is a bit more green in color:

It’s not strong enough to be noticed most of the time, and I’ve certainly seen worse – but I’ve also seen better. Under some conditions, it can harm lens’s bokeh a bit. Speaking of…

Bokeh

Even though this is hardly an 85mm f/1.8 lens, you can still get plenty of out-of-focus blur with this Nikon Z 24-120mm f/4 S, especially at 120mm and f/4. If you focus closely enough, the same can be true at the wider focal lengths, too.

So, how does the bokeh look on the Z 24-120mm f/4 S? Well, it’s actually pretty bad. There’s some chopped-off or “cat’s eye” background blur in the corners at every focal length, although it’s most obvious at 120mm. Here’s an uncropped photo of the effect:

On top of that, out-of-focus specular highlights take on a texture and have harsh edges. To my eye, the worst of it happens in the transition zones where something is only slightly out of focus. The following crop shows some of those unwanted effects, both in the background and foreground:

That’s some pretty bad performance. The background has classic “soap bubble” bokeh, and the foreground almost goes full Rubinar. (You don’t want to go full Rubinar.) In short, the Nikon Z 24-120mm f/4 S is not a lens for photographers who want creamy backgrounds.

Still, bokeh is in the eye of the beholder. I found myself enjoying these normally unwanted effects when I took some slightly spooky forest photos at 120mm and f/4. The hard-edged, nervous bokeh made the background shimmer in an eye-catching way. Meanwhile, the longitudinal chromatic aberration added to the dark rainbow of out-of-focus colors. It’s not “good bokeh” by any means, but it looked right for the mood I wanted to convey this time.

And a 100% crop:

Make the most of what you have, I suppose.

Flare and Sunstars

I’ve been very impressed by the Nikon Z 24-120mm f/4 S in backlit situations. It has great control over flare compared to most zoom lenses, and it doesn’t lose much contrast even when the sun is in the frame.

Throughout the zoom range, I found practically no flare when the sun was in the corner of the frame or outside the composition. The greatest amount of flare occurred when I composed the sun about halfway into the frame. This was true at every focal length. Stopping down made the dots of flare a bit more defined, but it didn’t add any additional flare.

As for sunstars on the Z 24-120mm f/4 S, they were better than I expected, and definitely above average for a zoom like this. Although I’ve occasionally seen better sunstars on wide-angle primes, I can’t complain about this at all:

If you stop down the lens to f/16 and partly obscure the sun with something in your frame, you can get good sunstars with this lens pretty consistently. You’ll have the most luck at 24mm, but the sunstars aren’t bad at longer focal lengths, either. Note that if the sunstar looks too big and blotchy in your photo, you probably haven’t obscured the sun enough.

In short, photographers can comfortably use the Z 24-120mm f/4 S when bright points of light are in the composition. The lens handles them very well, both in terms of flare and sunstars.

Sharpness

In our image quality tests so far, the Nikon Z 24-120mm f/4 S’s performance has ranged from bad (bokeh and distortion) to solid (vignetting and chromatic aberration) to very good (flare and sunstars). But what about the test that’s on everyone’s mind: sharpness?

Here, the Nikon Z 24-120mm f/4 S puts in a great performance with very crisp results throughout the zoom range and aperture range. Below, you can compare the lens’s focal lengths and see the strongest and weakest points. Fair warning – the difference between strongest and weakest on the 24-120mm f/4 S is much smaller than on most lenses!

Below are our Imatest charts from the wide to the long end of the focal length range. I’ll start with the performance at 24mm:

35mm:

50mm:

70mm:

105mm:

120mm:

That’s great sharpness all around – something that will become even clearer on the next page of this review, where I’ve juxtaposed these figures against those of other lenses on the market.

For now, though, what stands out to me the most is the impressive consistency of the Nikon Z 24-120mm f/4 S’s sharpness. You can pick any focal length from 24mm to 120mm, set any aperture from f/4 to f/8, and get sharp photos with very comparable performance among them. (If your aperture is especially narrow, like f/16, the effects of diffraction reduce the 24-120mm’s sharpness. But that’s true of any lens.)

Normally, midrange zooms have clear weak points somewhere in the range. The Nikon Z 24-120mm f/4 S manages to avoid this curse. It’s a bit weaker at 120mm, but only a bit – making this one of the most consistent zoom lenses I’ve seen. That’s an impressive feat for a 5x zoom.

That said, I did measure a bit of field curvature on the Nikon Z 24-120mm f/4 S. It’s not enough to harm real-world landscape photos under most conditions, though.

What about sharpness on more distant subjects? I find that performance is similarly high at infinity focus across all the focal lengths. It may be slightly less sharp at 105mm and 120mm in the corners compared to the corners at other focal lengths, but not by much.

Here are 100% crops at infinity focus starting at 24mm. Click to see them full resolution:

35mm:

50mm:

70mm:

105mm:

And 120mm:

What about close-focus distances? There, sharpness remains excellent in the center at every focal length, including at f/4. Corner sharpness at macro distances is definitely weaker, although that’s rarely a concern for close-up photos, where your corners are likely to be out of focus and/or unimportant.

In any case, here are 100% crops from both the center and corner, starting with the center at 120mm and f/4. (The excerpted area is the same size as the infinity focus photos above):

Next is a crop from the extreme top-left corner, again at 120mm and f/4. (Yes, the crop below is in focus, and it has no motion blur. This lens just loses some detail under these extreme conditions.)

That’s definitely the weak point of the lens: f/4 corner performance at close-focus distances. Still, since it’s hardly ever relevant to real-world photos, I wouldn’t worry. More importantly, center sharpness close-up remains extremely high.

Overall, you don’t need to worry much about focal length, aperture, or focusing distance if you want to take sharp photos with the Nikon Z 24-120mm f/4 S. It’s sharp all-around – a very forgiving lens.

How do these results compare to the performance of other lenses that you may be considering? That’s what I’ve covered next. So, click the menu below to go to the following page of this review, “Lens Comparisons.”