As we know a circle view at an angle appears as an ellipse, as you see in the picture, the center of the camera aim to the center of the circle , the angle between the circle axis and the camera is ө, the azimuth between mojor axis(a) and the camera is ∞, the rotation of the camera is €, 1. How to predict an orientation of major and minor axis and the ratio of its axes(b/a)?? ,if we only know these ө,∞,€ angle, regardless of size of ellipses. 2. Is there any theory to apply this example?