This summer I took our old, family SLR that stayed broken for a couple of decades and realized that I could actually use the lens.
It's fairly normal, 50mm Pentacon that you can find for about 20$.
Generally speaking, it's a "boring" lens.
It will not create any weird bokeh, flares, nothing...
It's as boring as Canon 50/f1.8.
Let me show you some examples I took during the night.
Helios sometimes annoys me at low aperture numbers because the flares are... Artistic...
Here's the first photo. There is no notable vignetting, sharpness is reasonable but not great and the contrast is fair.
Bokeh is very "neutral", no prominent hallos.
Now, the flares. Those are very discrete and a bit blue-ish and you can easily detect and remove them in postprocessing.
Short conclusion
For night conditions, this ultra-cheap lens performs very well.
I'll test it more in the daylight and according to my previous experience, it's not the best imaginable. But you will see