Two Hot Shoes wrote in post #18842944
Perhaps you might describe the 'some backgrounds' you mentioned above Alan, I'd really like to see this for myself so I can learn to avoid using the lens in those situations.
It might just be me but I find the foreground rendering in your photo a good example for "suboptimal rendering". It would have been interesting to see, how the XF 90mm f/2 or the Canon 70-200 f/4 on a Canon FF body would have rendered this scene, as both of these are less prone to ugly rendering in my experience. I don't know whether it's a matter of OIS or the placement of aspherical elements or what, but the 16-55 (no OIS, so maybe not that), the 50-140 and the 80 are much more sensitive to background, forcusing distance and subject to background/foreground distance while the 35/1.4, 90/2 or 56/1.2 are much easier in this regard. I've even seen very ugly rendering from the 200/2.
Maybe it's because I use Fuji lenses more, but I have much less difficulties with the respective Canon equivalents, plus these are more flare resistant as well. It's certainly not an insurmountable problem, but it's well worth being aware of it. Plus some people see it, some don't. Some like "swirly bokeh", some don't.