In the same model dome coater as in Case 11, we now compute for the thickness distribution on a spherical and concave lens surface situated in the same location. The concave surface has the same physical dimensions: 7 cm in diameter; its radius of curvature is -8 cm.
First we place the concave surface tangential to the dome surface. The resultant thickness distribution is highly nonuniform and asymmetric, shown in the left column of the figure below. Pivoting the surface by 13.4 degrees, the thickness distribution becomes more uniform and symmetric, as shown in the right column. The overall peak-to-valley nonuniformity before and after pivoting is 10.6% and 4.4%, respectively.