>>3909600After fiddling around with front irises, I can safely proclaim that swirly bokeh cant be explained by optical vignetting. I could ever only get the edges to swirl with vignetting alone. There's an additional element to swirl that I suspect is either radial astigmatism or uncorrected coma. I have a 35mm lens with pretty bad radial astigmatism fully open, but I'm also not seeing the same kind of swirl you get from actual swirly lenses with that.
So what do you guys think, is it coma? I dont even quite see how internal vignetting could affect the absolute center of the frame like it seems to with helios/jupiter, petzval or early summicrons.
Pic related is taken with a front iris, you can see some swirl in the oof but no much.
