If you find yourself standing above a transparent, shallow body of water you will notice that your angle of incidence ( that is the angle at which you look at the water) affects whether you can see through the water or whether you see only reflections upon the water. If you loook directly down you will be able to see through the water to objects on the bottom. The range of value difference among the objects under the water is not as wide as objects above the water ( the lights are lighter and the darks are darker above the water). As you slowly raise your eyes, ( your angle of sight or angle of incidence) you will be able to see less of what is under the water and more of the reflection on top of the water. The transition is subtle. In my painting note that the territory below the surface is also more blurred than objects above the water. That blur suggests that the water has some movement, a quality not found in the static forms above the water. Again, slowly raise your eyes and the area below the water gives way to the obscuring reflections on the surface ( the sky and other reflected objects) and, by the time your vision reaches the back area of the water it is entirely covered by reflection.