I have been trying out several wide angle lenses on my Sony A7. This weekend I managed to borrow a friend's Nikon 20 f1.8, a recent release. I also managed to spend the weekend in an area I simply love, southwest Portugal's coast.
So I went out at night with my daughter, set up the gear, programmed the camera for about two hours cumulative time. Each shot was 30 sec, ISO 1600. Now, aperture was just a nudge away from wide open on the Novoflex adaptor. At first, it is a bit disconcerting not knowing the actual aperture, but after a while, one gets used to it.
Focusing manually with the lens is not as difficult; of course the feel of the manual focus ring is not that great, there is no hard stop at infinity, and so on. But with zoom in the live view at 10X, it is easy enough to achieve focus on a bright star.
Since I arrived at arounf 9.30 pm, when it was not fully dark yet, I tried some landscape shots with the lens a bit stopped down. The lens is very good, sharp into corners and edges, and with surprisingly little barrel distortion on the horizon line.
I also shot some Milky Way photos, to try some panoramas, still working on those.
All in all, this seems to be a great lens: high performance, light, and not too expensive.
Regards.