How do I use the Find Edges filter?

Here we’ll use the filter to bring out a focal point. Start with a photo and duplicate the layer. Apply Find Edges to the duplicate. Change the blend mode to Luminosity and add a layer mask. With a soft, round brush, paint black to restore some of the original photo. To paint back the effect, use white. Jockey back and forth between white and black to get the optimal look. Apply a Hue/ Saturation adjustment layer and slide Saturation to the left. Paint black in the mask to bring back the colour of the focal point. Finally, apply a Levels adjustment layer.