Lens Sharpness, Contrast and Color Rendition
As I reveal in my sharpness tests in the subsequent sections of this review, the performance of the Nikon 1 10mm f/2.8 is very good in the center throughout its aperture range, even wide open. The corners suffer from some chromatic aberration and vignetting, especially wide open. You can see many examples of lens sharpness taken in a controlled environment, along with comparisons against other lenses.
A quick note on lens sharpness that generally applies to all Nikon 1 Nikkor lenses. Due to the small size of the sensor and the nature of compact optics, an aperture of f/5.6 is rather small and often represents peak lens performance. While diffraction negatively effects images on DX and FX sensors above f/8-f/11, it greatly impacts lens performance at anything smaller than f/5.6 on CX sensors. In the case of the Nikon 1 10mm lens, try to shoot at apertures between f/2.8 and f/5.6 for optimal results and do not stop down beyond f/8 or you will see a very heavy loss of resolution and contrast due to heavy diffraction. Unlike some other 1 Nikkor lenses, the lens minimum aperture is limited to f/11. This is yet another negative consequence of a small sensor camera design.
Bokeh
Due to the wide-angle nature of the lens and its short focal length, obtaining good bokeh would require you to shoot wide open at f/2.8 and stay very close to your subject. Again, the tiny CX sensor has a negative impact on depth of field, so if you shoot portraits and your goal is to better isolate subjects from the background, you will be better off with a longer focal length lens like the 1 Nikkor VR 30-110mm, or you might want to wait until Nikon releases a fast prime lens. If you are very close to your subject and the background is not too close, you can get a relatively good-looking background when shooting wide open at f/2.8. The lens is equipped with a rounded 7-blade diaphragm, which helps in obtaining circular bokeh highlights.
Vignetting
As for vignetting, there is a very noticeable amount of vignetting wide open at f/2.8, which is greatly reduced when the lens is stopped down to f/4. Unfortunately, a slight amount of vignetting stays visible at all apertures:
RAW shooters will see more vignetting in their images, because vignetting is automatically reduced on JPEG images. If vignetting is an issue for you, it is easy to fix in post-processing, so I would not worry about it. Adobe has already added a lens profile for the Nikon 1 10mm f/2.8 into Lightroom 3.6 and their Camera RAW 6.6, so you can easily remove the effect of vignetting with a single click through the Lens Corrections sub-module in Lightroom.
Ghosting and Flare
Thanks to clever lens design and Super Integrated Coating, the Nikon 1 10mm f/2.8 lens handles flares and ghosting quite well – one of the reasons why Nikon did not include a lens hood. Here is a sample image with the sun right in the frame:
If you see the effects of flare and ghosting in your images, then simply use your hand to block the incoming light rays. I have done that a few times when shooting on the field and it worked great.
Chromatic Aberration and Distortion
As I have already pointed out, the Nikon 1 10mm f/2.8 suffers from some chromatic aberration in the corners. The type of chromatic aberration I saw in my lab tests is green on one side and magenta on another. The good news is that this sort of chromatic aberration is absent in the center and is only pronounced in the extreme corners when shooting at a close distance. I went through many image samples that I shot outdoors and I could not find any images that showed this kind of aberration, which means that it is generally not an issue.
Some visible barrel distortion is present, which is very typical for a wide-angle lens. It is slightly less pronounced compared to the Nikon 1 10-30mm VR at 10mm, plus you can easily get rid of it using the Lens Correction module in Lightroom/Camera RAW. The latest version of Lightroom and Adobe Camera RAW fully support the Nikon 1 10mm f/2.8 lens.
Let’s now move on to the good stuff – Sharpness tests.
Sharpness Test – Nikon 1 10mm Center Frame
The wide-open performance of the Nikon 1 10mm in the center is superb and stopping down the lens does not seem to noticeably improve sharpness or contrast:
Lens sharpness drops a tad at f/5.6 and gets worse by f/8, due to diffraction:
Diffraction is pretty bad at f/11 as can be seen below:
The Nikon 1 lenses should never be used at such small apertures – I would not recommend shooting beyond f/8. The sweet spot for this lens seems to be at around the f/4 mark.
Sharpness Test – Nikon 1 10mm Corner Frame
Let’s see how the lens performs in the corners. The lens would have looked much sharper, if it wasn’t for some chromatic aberration that is visible in the extreme corners. Heavy vignetting is also quite noticeable at maximum aperture, but gets much better when stopped down to f/4:
The sweet spot in the corners seems to be at f/5.6, although stopping down to f/8 does not seem to hurt the image as much either:
Again, stopping down further to f/11 significantly impacts image sharpness due to diffraction:
The Nikon 1 10mm seems to perform best at f/4 in the center and at f/5.6 in the corners. The wide open performance is superb and I would not recommend shooting at f/11 due to heavy diffraction. Let’s see how the lens compares to other 1 Nikkor lenses.