Nikon D3400 Optics

Zoom
A typical 3.1x zoom ratio for a DSLR kit lens, with mixed performance.

As previously mentioned, the Nikon D3400 comes bundled with the new Nikkor AF-P DX 18-55mm f/3.5-5.6G VR kit lens. This 3.1x zoom lens has a 35mm-equivalent focal length of about 27-83mm because of the D3400's 1.5x APS-C "crop factor."

Sharpness and contrast are excellent across most of the frame at full wide angle and f/8, however corners show some moderately high chromatic aberration and extreme corners show some minor blurring. Optical performance at a medium focal length of 35mm (52mm eq.) unfortunately isn't as good, with somewhat soft results across the frame, although chromatic aberration is very low. Performance at full telephoto is decent at f/8, with good sharpness and contrast across much of the frame, however the lens is not as sharp as at wide angle, particularly on the right-hand side of the frame. See below for our studio test results.

Macro
A slightly smaller-than-average macro area, with good detail overall. Flash throttled down well.

The Nikon D3400 captured a slightly smaller-than-average macro area (meaning it can focus closer than average) with the AF-P 18-55mm VR kit lens, measuring 2.22 x 1.48 inches (56 x 38 millimeters). Performance is good, just a touch soft across most of the frame, and there's not much additional softness in the corners. (Most lenses have more softening in the corners at macro distances.) The Nikon D3400's built-in flash throttled down well at minimum distance, resulting in a well-exposed image with fairly even flash coverage.

Geometric Distortion
Higher-than-average barrel distortion at wide angle from the 18-55mm kit lens.

The Nikon AF-P 18-55mm VR kit lens produced about 1.3 percent barrel distortion at wide angle, which is higher-than-average and quite noticeable in its images. At the telephoto end pincushion distortion is just under 0.1 percent, which is hardly noticeable. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).

Auto Distortion Control
Very low geometric distortion when Auto Distortion Control is enabled.

The Nikon D3400 offers an Auto Distortion Control feature to reduce geometric distortion automatically with most modern Nikkor lenses. As you can see it worked quite well with the 18-55mm lens, reducing barrel distortion at wide angle to only about 0.2%, and overcorrecting pincushion at telephoto slightly to about 0.1% barrel distortion. Note that some of the image is cropped away in the process at wide angle, though. Since this option is database driven, it's only available for Nikkor D, E and G-type lenses with certain optics such as Fisheye and Perspective Control lenses excepted. Auto Distortion Control is Off by default.

You can also apply Auto or Manual Distortion Control to JPEGs after the fact in the camera's Retouch menu, and Manual mode works with images from any lens.

Chromatic Aberration and Corner Sharpness
Low to moderately high C.A. in JPEGs, higher in uncorrected RAW files. Corners are soft when wide open, but improve when stopped down.

Chromatic Aberration. Chromatic aberration in the form of fairly bright blue and yellow fringing is moderately high in the corners at the full wide-angle, despite being suppressed by the D3400's image processor. (See below for crops from uncorrected RAW files.) At full telephoto, chromatic aberration is low and hardly visible. (This distortion is visible as a slight colored fringe around the objects at the edges of the field of view on the resolution target.)

Corner Sharpness. The AF-P 18-55mm VR kit lens produced somewhat soft corners at full wide angle when wide-open at maximum aperture, although corner performance is better than average for an inexpensive kit lens. All four corners show a similar amount blurring with the bottom right showing just a bit more, and softness doesn't extend very deep into the frame. The center is however quite sharp. At full telephoto, all four corners are also somewhat soft. The center is pretty sharp, though not quite as sharp as at wide angle.

Vignetting. There is some fairly strong vignetting (corner shading) at the wide end of the zoom and some mild vignetting at the telephoto end, as indicated by the darker corner crops. (Note that the D3400 has built-in shading correction for JPEGs with Off, Low, Normal (default) and High settings, and these images were taken with it set to Off.)

F8. Stopped-down to an aperture of f/8, corner performance improved at both wide angle and full telephoto with better sharpness and contrast, but chromatic aberration is still moderately high at wide angle. Center sharpness also improved, but full telephoto is still not as sharp as wide angle. Vignetting is negligible at wide angle and practically nonexistent at full telephoto.

Uncorrected Raw
Higher levels of C.A. in uncorrected Raw files.

As you can see from the crops above comparing camera JPEGs (on the left) to uncorrected NEF files (right), lateral chromatic aberration is higher in uncorrected RAW files. Thus, the D3400's JPEG engine is indeed suppressing lateral chromatic aberration, but there is lot to contend with in the corners at wide angle which it failed to eliminate entirely. The camera was much more successful at suppressing the lower amounts of chromatic aberration at full telephoto.


Bottom line: Fair to very good optical performance for a kit lens but it's a bit surprising how much chromatic aberration is present in the corners at wide angle, and that Nikon doesn't correct for distortion by default in a consumer model these days.

Coverage
Slightly better than average coverage accuracy from the optical viewfinder for an entry-level DSLR. Good accuracy from the LCD in Live View mode.

The Nikon D3400's optical viewfinder showed about 96 percent coverage with our Nikkor 60mm f/2.8 macro lens. This is better-than-average coverage for an entry-level digital SLR, exceeding Nikon's specification of 95%. However the viewfinder image is slightly shifted horizontally and vertically compared to the image sensor, which unfortunately is not that uncommon in consumer models. In Live View mode, the Nikon D3400's LCD showed about 99% coverage, which is good though we often see 100% coverage here.