What went wrong with this shot D5100 with f/1.8 lens

One thing I have learned in my years of shooting, esp using new gear, is to read up and try to understand the basics, then go practice. And you don't have to wait for another event. Find a similar scene and shoot with both lenses / different techniques and see which give the results you like.

I also have learned to take each lens on a tripod and shoot a real world shot at every f stop so I can see what compromises in IQ I am making if I need to venture from "best setting". I know for some lenses wide open isn't a good option, for others it has very little impact on IQ. Don't just read reviews because every sample of a lens can be different as well.

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Stacey