jt49

You should (in most cases) work with the default value of -100. I just compared the full screen view of a static image that I presented in PTE at values 0 and -100, and compared the results with IrfanView. At a value of 0 the image is slightly more soft. The slider sharper/smoother is to be used to control the process of mipmapping (anti-shimmering) in case of animations rather than to sharpen/blur static images. See here. jt

Another way: Settings > Preferences > Timeline > Tracks jt