Did you know, KEE friends, that the shape of bokeh is not just round? Most recent lenses are now designed to produce bokeh with a round shape or what is known as a circular aperture. But for KEE friends who have old model lenses, maybe your lenses still produce polygonal bokeh shapes.
It turns out that the shape of the bokeh is influenced by the design of the aperture shape in such a way that it influences the shape of the resulting bokeh.
Circular aperture
Source : https://snapshot.canon-asia.com/
Non-Circular aperture