More Sigma tests. These shots are looking for the onion ring in lights. They are pretty much what I've seen in the numerous examples around. I did a quick garage setup with just a garage light overhead and what you see in the background.
ISO 100, f2, Exposure comp -2/3EV
At closer inspection you can see it on ones that don't have clipped lights. I guess if you make large prints...
And here is using the lens more candidly. So if you shoot these kinds of shots all the time, having a lens with gaussian blurred spheres might be more appealing.
ISO 2800, f1.6, Exposure comp -1EV
ISO 1600, f2.2, Exposure Comp -1EV