At the moment there are two waterproof lenses available for the Nikon 1 AW1: The AW 11-27.5mm f/3.5-5.6 zoom lens (included in the kit) and the smaller AW 10mm f/2.8 fixed focal length pancake lens. Since I will probably be using the zoom for more than 90% of my shots at the widest setting I was curious whether I would also get better image quality in addition to a more compact setup if I change to the 10mm lens.
All test images were shot from a stable Gitzo tripod using the self-timer. For focusing, AF was used, but every shot was repeated at least twice. By choosing the sharpest images for each setting afterward the risk for AF errors of the camera was reduced. All RAW images were processed with identical settings and sharpening of 50/0.7/50/0 in LR.
For the first two tests, I used again a flat wall at a medium focus distance of 5-10m.
This is an image of the first test subject followed by some 100% crops:
AW 10mm, f/2.8, center:
AW 10mm, f/4, center:
AW 11-27.5mm, @11mm, f/3.5, center:
AW 11-27.5, @11mm, f/4, center:
AW 10mm, f/2.8, corner:
AW 10mm, f/4, corner:
AW 11-27.5mm, @11mm, f/3.5, corner:
AW 11-27.5, @11mm, f/4, corner:
And here is an image of the second test subject followed by some 100% crops:
AW 10mm, f/2.8, center:
AW 10mm, f/4, center:
AW 11-27.5mm, @11mm, f/3.5, center:
AW 11-27.5, @11mm, f/4, center:
AW 10mm, f/2.8, corner:
AW 10mm, f/4, corner:
AW 11-27.5mm, @11mm, f/3.5, corner:
AW 11-27.5, @11mm, f/4, corner:
The third test was shot near infinity:
AW 10mm, f/2.8, center:
AW 10mm, f/4, center:
AW 11-27.5mm, @11mm, f/3.5, center:
AW 11-27.5, @11mm, f/4, center:
AW 10mm, f/2.8, right edge:
AW 10mm, f/4, right edge:
AW 11-27.5mm, @11mm, f/3.5, right edge:
AW 11-27.5, @11mm, f/4, right edge:
Stopping further down to f/5.6 very slightly reduces the overall sharpness on both lenses while using f/8 significantly reduces the IQ and should really be avoided.
At closer distances, the difference between the two lenses is very small. The 11-27.5mm zoom has slightly better corner sharpness and the 10mm lens has slightly better center sharpness wide open. Stopped down to f/4 the differences are negligible.
At infinity, the 11-27.5mm zoom has a much better image quality outside of the center area.
If you want to have a universal lens for all situations the kit-zoom is clearly the better choice. If you need a lens only for underwater photography or for images shot at close distances the 10mm lens is a very good alternative since it is much smaller. I will stay with the kit-zoom.
Wild Places 
Thanks, Boris. I just sent in my AW1 for repairs after a small leak in the battery compartment appeared after some light 3 meter snorkeling. The camera was repaired free, but they wanted $165 to repair the 11-27.5mm which is more than its retail price, so I’m looking to buy a new lens for underwater use. I’ll take your advice and go with the 10mm, as I don’t want to risk any possibility of further leakage, and build quality appears higher as you mentioned. It’s actually rated to 20m which is more than the camera (perhaps an AW2 will one day appear?) Also, I saw one review that stated the 10mm AW is made in Japan.
I’ve found I get much better results underwater by ignoring the manual and *NOT* using the underwater mode, which resorts to JPG only, but shooting in raw. The JPG engine in AW1, unlike in my d750, is not the best, and the underwater mode appears to be a gimmick.
I agree 100%. The IQ of the RAW images of the AW1 is so much better compared to the JPG images that I always shoot in RAW, even for family snapshots. And I’ve never used the underwater mode, only A, P and M.
Thanks for this comparison. I’m surprised and disappointed the fast prime under performs the kit lens. Still, I’m tempted to try the 10mm for underwater shots, as I am often getting blurry shots from lack of light and the wider aperture would help, although it’s really only 2/3 stop faster so I’d only buy if it was heavily discounted.
If you use the lens only underwater I would recommend the 10mm. The center sharpness is very good and underwater perfect corner sharpness is rarely needed. In addition there are a lot more reported leakage problems with the kit zoom. Even my kit zoom had to be exchanged under guarantee due to leakage. I’ve never heard of any problems with the 10mm lens.