This was with my ancient non-AI Vivitar 85-205 zoom mounted on my D3200, taking pictures of the sunlight through some trees, intentionally out of focus, just to produce a pure bokeh effect. There' also a bit of a flare in this picture.
Taking the concept a bit farther, last night, I made this disk to go on the front of my equally-ancient non-AI 50mm ƒ1.4 lens:
And using this to take pictures, similar in technique to the previous one, I got this: