In this week we learned about the perspective of ellipses. It is quite counter-intuitive to draw these in perspective.
Because the major and minor axis are ALWAYS perpendicular to each other, you do not use the perspective in these guidelines.
It sounds like it is easy, but when you try it, it needs some time to sink in.
We applied these in sketching cameras and other objects with round shapes in them (e.g. cups and watches).