y issuing an <strong>RTG
ALL</strong> or an <strong>RTG 8</strong> command. The thickness of
surface 9 has now changed to 0.474615 mm in order to maintain paraxial
focus. There are other optimization methods described in the reference
manual which you should try.</p>

<h2>Lesson #9 - A Merit Function using Predefined and User-defined
  Operands</h2>

<p>Here is a simple example of a senseless (not intended to be a
meaningful figure of merit) merit function which is made up of ray
based and non-ray based use