In ON1 Photo RAW you can quickly and easily create and blend masks when editing photos. Use luminosity masks to blend filters and local adjustments to your photos easily. Luminosity masks will enable you to control your mask based on your photos bright and dark areas. Another easy way to blend a filter would be to use a color range mask. Color range masks allow you to create a mask using specific colors. Once you have a mask created, you can blend and refine it quickly using the masking tools.
The chisel mask tool will help you refine your edge so that you don’t have any extra fringe or overlapping edges. Double click the icon itself to chisel the edge away around the entire mask. If you are having trouble refining your mask around sharp edges such as hair or trees, use the refine brush to help you blend the mask more naturally. The refine brush is an excellent tool for small areas of tonal contrast, and it will help your mask look more realistic.