Stopped Down
As I closed the iris further, the glow continued to decrease. However I also noted an unexpected change. There is a big increase in off-axis blur and false color. I shot the same scene at about f/ 16
It's an interesting effect, however it's not what I was intending with this lens. I suspect that the iris is not positioned correctly. I haven't run this through any lens design software yet, but I suspect that the iris should be much closer to the rear elements. Once again, realities of amateur lens making show up. The size of my Ilex shutter doesn't allow me to mount it any closer to the rear elements.
At some point I will find a "lower profile" focuser, the correct positive meniscus, and a properly sized iris. For now I'm happy with the results of my latest, easy-to-use lens.