In this image, the spillover of the white onto the couple’s shoulders can make things complicated for selections by other means. Calculations provide an easy way to create a solid starting-point for the mask. Begin by selecting the Red channel for the Source 1. And the Blue channel for Source 2. Tick the Invert box for the Blue channel and set the blending to Vivid Light. This will yield a high contrast selection with the outlines clearly visible. A quick visit to Levels and then some minor touch-ups with your tools and you’ve got an exceptional mask around these beachcombers.