What are the common complaints about the bokeh of the Sigma 50mm f/1.4 ART

1. Onion ring effect: Some users have noted the presence of "onion rings" in the bokeh, which can detract from the overall smoothness of the out-of-focus areas[2].

2. Defined edges on highlights: When shooting wide open at f/1.4, the edges of background highlights can be more defined or pronounced compared to some other lenses, particularly when the out-of-focus area is in front of the focused subject[2].

3. Less pleasant bokeh when stopped down: While the lens performs well at f/1.4, some reviewers found that when stopped down to f/2.0 and beyond, the bokeh becomes less pleasant and more defined compared to lenses like the Nikon 50mm f/1.4G[2].

4. Color fringing: In some situations, visible color fringing can appear in out-of-focus areas, especially when the bokeh is in front of the focused area[2].

5. Inconsistent performance: The bokeh quality seems to vary depending on the shooting scenario. It performs better in some situations (e.g., background blur at f/1.4) but worse in others (e.g., foreground blur)[2].

6. Not as smooth as some competitors: While generally good, some reviewers found the bokeh not as smooth as higher-end options like the Nikon 58mm[4].

It's worth noting that despite these complaints, many users still find the overall bokeh quality of the Sigma 50mm f/1.4 ART to be good, especially considering its price point. The lens is often praised for its sharpness and overall image quality, with bokeh being just one aspect of its performance.