A system for optical navigation includes a light source and an imaging system. The light source illuminates a navigation surface. The navigation surface reflects light from the light source. The imaging system is located approximately within a path of the reflected light. The imaging system includes a lens, a mask, and an image sensor. The lens receives reflected light from the navigation surface. The lens focuses a specular portion of the reflected light to a focus region. The mask is located at approximately the focus region. The mask filters out substantially all of the specular portion of the reflected light and passes at least some of a scatter portion of the reflected light outside of the focus region. The image sensor generates a navigation signal based on the scattered portion of the light that passes outside the focus region and is incident on the image sensor.