Here’s a quick look at how I created some homemade “petzval swirl” bokeh that mimics photos taken with the new Petzval 58 Bokeh Control Art lens, which gets its function from an old Russian lens, the Helios 44-2.
Basically, on my 50mm 1.8 prime lens (Yes, a prime lens is a requirement!) I cut a small hole in light-proof paper over my lens hood, and taped it together, to produce some cheapo Petzval bokeh that swirls the background at wide apertures. Vignetting is a problem, however. You may have to change the size of the hole in the paper to remove this. It’s cheap, and works pretty well… but at the cost of looks.
Here's some images of the setup:
Below is an image taken with the *actual* Helios 44-2 58mm lens that this hack is based off of. These lenses are old and cheap, but can really only be bought from Russia, on ebay, so they take 2-4 months to make their way across the pond.