The sharpness filter at the high setting produces a bright halo around dark details and a dark halo around light details in the image, as you can see around the antenna on the rooftop of the car:

At the medium setting, which is the default, the halo produced by the software filter is still noticeable (at 200% enlargment), but not so marked:

At the low setting the artifical halo is practically absent. The visual effect at 100% enlargement is a bit blurry, you may want to use this setting for a face closeup to hide the skin imperfections or if you intend to apply a sharpness filter on post production: