Thank you for the question. I did this pic in Sai but it is the same thing in Photoshop. First, just try to observe the light and dark parts of the ripples in the photos. And then, make two new layers and change their modes to draw these parts. Try to draw the dark parts in the layers with the "Multiply"or "ColorBurn" mode, and the light parts with the "Lighten"or"Screen" one. I hope it can be help. Just enjoy your drawing.