If you enjoy experimenting with bokeh shapes, I’ve found a perfect tutorial for you. Mathieu Stern is known for his solutions which are so simple that they are ingenious. In under a minute, he’ll teach you how to create spectacular “bokeh explosion” with a simple modification of the lens.
Mathieu uses a MIR-1B, a cheap Russian lens you can find online or probably even at flea markets. Here’s what you’ll need for this hack:
So, what are you to do with these items? All you need to do is remove the front lens, reverse it, and put it back where it was. And voila, you have your lens with explosive bokeh ready to go. Of course, be careful not to damage the lens. Everything else seems pretty easy and takes only a minute or so to get it done.
When you reverse the front element, the lens will be sharp in the middle. Around the edges, it will have the effect which is a bit similar to zooming in while exposing. Here’s how it turned out for Mathieu during the night:
It can give cool results during the day as well:
I’m guessing you don’t need to use precisely MIR-1B to achieve the effect. One of the comments says you can also use a Helios 44-2, and some other lenses could work as well. So, if you are willing to experiment with old lenses, this is one of the ideas you could definitely try.
[How to Create a Stunning Bokeh Explosion at Night | Mathieu Stern]