Streetcar -- NEX-5N & Tokina 17mm f3.5. Click for larger.
One of the annoyances with ultra wide angle lenses is that they are very difficult to focus manually. That's because so much is sucked into the picture with such a wide viewing angle and everything looks smaller. This is especially bad if the adapter is not very precise. The adapter I have, is way past infinity at the mark. The lens reaches infinity between 5 and 10 meter mark on the distance scale.
CN Tower in the distance -- NEX-5N & Tokina RMC 17mm f3.5. Click for larger.
I think I will mark it on the lens so aid me focusing. Basically, at f8, anything from a few feet away to infinity is in focus, as long as I get the infinity mark correct.
In terms of sharpness, I have no issues with it. Naturally, we should not expect the same sharpness of a 17mm lens as the 50mm, but it's plenty sharp. The corners is acceptable stopped down on the NEX-5N, and I suspect they are not quite as good with full frame. Need to shoot this lens in a different lighting to see if it's the lens that produces odd colours or the lighting.
Beautiful new mural -- NEX-5N & Tokina RMC 17mm f3.5. Click for larger.