Nikon Z DX 18-140mm f/3.5-6.3 VR Review

Focusing Characteristics

The Nikon Z DX 18-140mm f/3.5-6.3 autofocuses fairly quickly and quietly, better than expected. Accuracy is as high as any other Nikon Z lens – which is to say, excellent. Although it’s true that some lenses can rack focus a little faster, this lens is speedy enough for basic sports and wildlife needs.

Because of the narrow maximum aperture (f/3.5 at 18mm, gradually dimming to f/6.3 as you zoom in), focusing in low light can be a challenge. And you can’t improve things by focusing at the brightest focal length of 18mm, then zooming in – the lens’s focus position changes as you zoom. In particularly low light, you may need to wait a second or two before the camera is able to lock onto your subject properly.

In terms of close-focusing capabilities, the maximum magnification of this lens is an impressive 0.33x (1:3 magnification). This means you can fill the frame with a subject that is just 7.1 cm / 2.8 inches wide with a Nikon DX camera. Although that’s not technically macro photography territory, it’s pretty close, and it adds to the lens’s versatility.

Distortion

The Nikon Z DX 18-140mm f/3.5-6.3 has fairly high distortion throughout the zoom range. This isn’t a surprise for a wide-to-telephoto zoom (cheap or not). Here’s the full graph of distortion measurements as determined in Imatest:

The maximum barrel distortion of -5.91% at 18mm is quite pronounced. At 24mm, there is hardly any distortion. As you zoom into 35mm and longer, the lens holds pretty steady around 2.5 to 3.0% pincushion distortion, which is not too bad.

Here’s a simulation of -5.91% barrel distortion and 2.96% pincushion distortion for reference:

Keep in mind that this distortion will be automatically corrected in most post-processing software, so you may never even see it in the first place. Still, correcting -5.91% barrel distortion comes with a small penalty: a little less sharpness in the corners of the image as they are stretched back in place.

Vignetting

In uncorrected images, the Nikon Z DX 18-140mm f/3.5-6.3 has moderately high levels of vignetting wide open, though it depends on your focal length. It’s worst at 18mm and f/3.5, which is no surprise. There is minimal difference between vignetting at close focus and infinity focus with this lens, but I’ll show both charts regardless:

The maximum of 2.34 stops is significant, but hardly the worst we’ve seen. It’s low enough that you can reduce or remove it in post-processing without revealing too much excess image noise in the corners of the photo.

As you zoom into 24mm and beyond, the vignetting on this lens is extremely manageable, even when shooting at maximum aperture. This is a lot better than I expected!

Lateral Chromatic Aberration

Nikon has kept lateral chromatic aberration pretty well-managed on the Nikon Z DX 18-140mm f/3.5-6.3, especially compared to a lot of cheap zooms. It’s still not zero, but as you can see from the chart below, it never reaches extreme levels:

Anything under about one pixel in our measurements is almost impossible to notice in real-world images, even with chromatic aberration corrections turned off. Once you reach over the 2-pixel mark, it can be difficult to remove this chromatic aberration without leaving some artifacts behind in the photo (either lingering color or haloing effects).

The exact amount depends on your focal length and aperture, but the Nikon Z DX 18-140mm f/3.5-6.3 ranges from 0.50 pixels of lateral CA to 2.04 pixels. This covers everything from negligible to a little high. Still, even at its worst, you should not experience any significant issues correcting chromatic aberration in post-processing with this lens.

Sharpness

Now the moment you’ve all been waiting for! The Nikon Z 18-140mm f/3.5-6.3 VR is pretty sharp, especially at the wide end. Even the telephoto performance is totally reasonable, though.

Here’s how it performs throughout the zoom range:

This is a totally respectable performance. In the range from 18mm to 50mm, it’s downright impressive – and even from 70mm onward, it’s reasonably sharp the whole time. This will become clear on the next page of this review, which includes head-to-head lens comparisons.

The sharpest aperture on this lens ranges from f/4 to f/8 depending on the focal length, although keep in mind that this is only for photos of a flat subject. If you need more depth of field, you shouldn’t hesitate to use apertures like f/11 or even f/16, despite those apertures losing some sharpness because of diffraction.

Keep in mind that the numbers in the charts above are only directly comparable to measurements on Photography Life from other Nikon DX lenses. However, you can still look at our Nikon FX sharpness tests to see how that particular lens would perform on DX – just look only at the “center” and “mid” values of the FX lens in question, and divide them by 1.5. That will show you how it performs in the center and corners on DX, if you want to compare it directly to the numbers above.

Flare and Sunstars

Usually, complex zoom lenses like this one are textbook examples of bad flare performance. As soon as the sun gets in your photo, you’re likely to see bright reflections of light across the image, and a significant loss in contrast.

The Nikon Z DX 18-140mm f/3.5-6.3 is not totally an exception, but it depends on the photo. If the sun is too bright in your photo, you’ll get some substantial rainbow-like flare near the sun itself. Take a look at the following two examples:

However, if the sun is sufficiently covered by something in the photo, the Nikon Z DX 18-140mm f/3.5-6.3 retains excellent contrast and exhibits hardly any flare. Just make sure that you keep the front of the lens clean – for whatever reason, dust on the front element of this lens invites a little more flare than usual.

As you can see from the photo above, the sunstars on this lens are also surprisingly nice. If you stop down your lens to f/11 or f/16 and cover the sun enough, you’ll get well-defined 14-blade stars.

The next page of this review dives into the sharpness numbers a bit more, with some comparisons against other lenses that Nikon users may be considering. So, click the menu below to go to “Lens Comparisons”: