Anyone who has walked along a riverbank and gazed at the ever-changing patterns of light and shadow reflected in the river’s movement can recognize the basis of Ellen Kozak’s practice: fleeting optical sensation. Visiting the Hudson River each morning, Kozak often painted with the water floating below her easel and seat, positing the surface of the water as a thin boundary between two infinite views: the sky above, and the river below. Like a Zen rock garden, the thick brush strokes on the painting’s surface suggest solidity while simultaneously pointing to the fleeting and impermanent nature of observed reality itself.