Cone-axis ellipsoidal reflectors are the transfiguration of ellipsoidal reflectors. An ellipse axis that based on the first focal point(F1) turns an angle of   , and then half of the ellipse that has angle rotates one circle around the original axis. There will be a

spherical line formed in the second focal point(F2). When a light source is placed at the first focal point(F1) of the reflector, the ellipsoidal reflector redirects light that would otherwise miss the target are(F2).

These reflectors are coated with dichroic coating. Substrate is glass. Cone-axis ellipsoidal cold reflectors are ideal for illumination systems where high temperature lighting is not desired.