Hello Ken,
If you're interested in purchasing this lens then read the following review (over 12 webpages) with glee. It's a fantastic result with excellent control of coma (see p7) and class leading (or close to it) resolution (see p4). The only downside is marginally worse vignetting compared with its Canon or Zeiss rivals, which cost many times more and of course no autofocus if you need it for daytime photography.
https://www.lenstip.com/index.html?t...wu&test_ob=442
Best
JA