In Depth Study: How Shutter Speed and Aperture Mangle Bokeh with Electronic First Curtain Shutter (vs electronic shutter and mechanical shutter)
I was vaguely aware of bokeh differences with fast lenses at high shutter speeds, but since I usually shoot the sweet light whenever I can, it was never much of an issue.
In Making Sharp Images, I show how shutter speed and aperture mangle bokeh with electronic first curtain shutter versus electronic shutter and mechanical shutter. These findings will apply to all lenses of any brand on modern digital cameras with only slight variation.
This page takes a thorough look how bokeh changes depending on aperture, shutter speed, and type of shutter: